1
|
Andrade MR, Azeez TA, Montgomery MM, Caldwell JT, Park H, Kwok AT, Borg AM, Narayanan SA, Willey JS, Delp MD, La Favor JD. Neurovascular dysfunction associated with erectile dysfunction persists after long-term recovery from simulations of weightlessness and deep space irradiation. FASEB J 2023; 37:e23246. [PMID: 37990646 DOI: 10.1096/fj.202300506rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 09/19/2023] [Accepted: 09/26/2023] [Indexed: 11/23/2023]
Abstract
There has been growing interest within the space industry for long-duration manned expeditions to the Moon and Mars. During deep space missions, astronauts are exposed to high levels of galactic cosmic radiation (GCR) and microgravity which are associated with increased risk of oxidative stress and endothelial dysfunction. Oxidative stress and endothelial dysfunction are causative factors in the pathogenesis of erectile dysfunction, although the effects of spaceflight on erectile function have been unexplored. Therefore, the purpose of this study was to investigate the effects of simulated spaceflight and long-term recovery on tissues critical for erectile function, the distal internal pudendal artery (dIPA), and the corpus cavernosum (CC). Eighty-six adult male Fisher-344 rats were randomized into six groups and exposed to 4-weeks of hindlimb unloading (HLU) or weight-bearing control, and sham (0Gy), 0.75 Gy, or 1.5 Gy of simulated GCR at the ground-based GCR simulator at the NASA Space Radiation Laboratory. Following a 12-13-month recovery, ex vivo physiological analysis of the dIPA and CC tissue segments revealed differential impacts of HLU and GCR on endothelium-dependent and -independent relaxation that was tissue type specific. GCR impaired non-adrenergic non-cholinergic (NANC) nerve-mediated relaxation in the dIPA and CC, while follow-up experiments of the CC showed restoration of NANC-mediated relaxation of GCR tissues following acute incubation with the antioxidants mito-TEMPO and TEMPOL, as well as inhibitors of xanthine oxidase and arginase. These findings indicate that simulated spaceflight exerts a long-term impairment of neurovascular erectile function, which exposes a new health risk to consider with deep space exploration.
Collapse
Affiliation(s)
- Manuella R Andrade
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Tooyib A Azeez
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - McLane M Montgomery
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Jacob T Caldwell
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Hyerim Park
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Andy T Kwok
- Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Alexander M Borg
- Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - S Anand Narayanan
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Michael D Delp
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Justin D La Favor
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| |
Collapse
|
2
|
Kunkel ON, Rand TA, Pyle JG, Baumfalk DR, Horn AG, Opoku‐Acheampong AB, Ade CJ, Musch TI, Ramsey MW, Delp MD, Behnke BJ. Head-up tilt does not enhance prostate tumor perfusion or oxygenation in young rats. Physiol Rep 2022; 10:e15548. [PMID: 36564177 PMCID: PMC9788965 DOI: 10.14814/phy2.15548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/25/2022] Open
Abstract
Solid tumors contain hypoxic regions that contribute to anticancer therapy resistance. Thus, mitigating tumor hypoxia may enhance the efficacy of radiation therapy which is commonly utilized for patients with prostate cancer. Increasing perfusion pressure in the prostate with head-up tilt (HUT) may augment prostate tumor perfusion and decrease hypoxia. The purpose of this study was to determine if an increase in the vascular hydrostatic gradient via 70° HUT increases tumor perfusion and decreases tumor hypoxia in a preclinical orthotopic model of prostate cancer. Male Copenhagen rats (n = 17) were orthotopically injected with Dunning R-3327 (AT-1) prostate adenocarcinoma cells to induce prostate tumors. After tumors were established, prostate tumor perfusion and hypoxia were measured in rats during level (0°) and 70° HUT positions. To compare the magnitude of the hydrostatic column to that present in humans, ultrasound was used to measure the heart to prostate distance in male human subjects to estimate the prostate vascular hydrostatic pressure with the upright posture. In young rats, no differences were detected in prostate tumor perfusion or prostate tumor hypoxia with 70° HUT versus the level position. However, from the retrospective study, young rats increased prostate vascular resistance to HUT, whereas aged rats lacked this response. Tumor vessels co-opted from existing functional vasculature in young rats may be sufficient to negate increases in perfusion pressure with HUT seen in aged rats. Additionally, in humans, the estimated hydrostatic column at the level of the prostate is five times greater than that of the rat. Therefore, 70° HUT may elicit increases in prostate/prostate tumor blood flow in humans that is not seen in rats.
Collapse
Affiliation(s)
- Olivia N. Kunkel
- Department of KinesiologyKansas State UniversityManhattanKansasUSA
| | - Taylor A. Rand
- Department of KinesiologyKansas State UniversityManhattanKansasUSA
| | - Joseph G. Pyle
- Department of KinesiologyKansas State UniversityManhattanKansasUSA
| | | | - Andrew G. Horn
- Department of KinesiologyKansas State UniversityManhattanKansasUSA
| | | | - Carl J. Ade
- Department of KinesiologyKansas State UniversityManhattanKansasUSA
| | - Timothy I. Musch
- Department of KinesiologyKansas State UniversityManhattanKansasUSA,Department of Anatomy and PhysiologyKansas State UniversityManhattanKansasUSA
| | - Michael W. Ramsey
- Department of Sport, Exercise, Recreation, and KinesiologyEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Michael D. Delp
- Department of Nutrition, Food and Exercise SciencesFlorida State UniversityTallahasseeFloridaUSA
| | - Bradley J. Behnke
- Department of KinesiologyKansas State UniversityManhattanKansasUSA,Johnson Cancer Research CenterKansas State UniversityManhattanKansasUSA
| |
Collapse
|
3
|
R Andrade M, Azeez TA, Montgomery MM, Caldwell JT, Park H, Narayanan SA, Delp MD, La Favor JD. The Impact of Long‐Duration Exposure to Microgravity and Galactic Cosmic Radiation on Corpus Cavernosum Function. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r5470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
4
|
Kwok AT, Mohamed NS, Plate JF, Yammani RR, Rosas S, Bateman TA, Livingston E, Moore JE, Kerr BA, Lee J, Furdui CM, Tan L, Bouxsein ML, Ferguson VL, Stodieck LS, Zawieja DC, Delp MD, Mao XW, Willey JS. Spaceflight and hind limb unloading induces an arthritic phenotype in knee articular cartilage and menisci of rodents. Sci Rep 2021; 11:10469. [PMID: 34006989 PMCID: PMC8131644 DOI: 10.1038/s41598-021-90010-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/15/2021] [Indexed: 11/18/2022] Open
Abstract
Reduced knee weight-bearing from prescription or sedentary lifestyles are associated with cartilage degradation; effects on the meniscus are unclear. Rodents exposed to spaceflight or hind limb unloading (HLU) represent unique opportunities to evaluate this question. This study evaluated arthritic changes in the medial knee compartment that bears the highest loads across the knee after actual and simulated spaceflight, and recovery with subsequent full weight-bearing. Cartilage and meniscal degradation in mice were measured via microCT, histology, and proteomics and/or biochemically after: (1) ~ 35 days on the International Space Station (ISS); (2) 13-days aboard the Space Shuttle Atlantis; or (3) 30 days of HLU, followed by a 49-day weight-bearing readaptation with/without exercise. Cartilage degradation post-ISS and HLU occurred at similar spatial locations, the tibial-femoral cartilage-cartilage contact point, with meniscal volume decline. Cartilage and meniscal glycosaminoglycan content were decreased in unloaded mice, with elevated catabolic enzymes (e.g., matrix metalloproteinases), and elevated oxidative stress and catabolic molecular pathway responses in menisci. After the 13-day Shuttle flight, meniscal degradation was observed. During readaptation, recovery of cartilage volume and thickness occurred with exercise. Reduced weight-bearing from either spaceflight or HLU induced an arthritic phenotype in cartilage and menisci, and exercise promoted recovery.
Collapse
Affiliation(s)
- Andy T Kwok
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Nequesha S Mohamed
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Johannes F Plate
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Raghunatha R Yammani
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA.,Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Samuel Rosas
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Ted A Bateman
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Eric Livingston
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Joseph E Moore
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Bethany A Kerr
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA.,Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jingyun Lee
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.,Proteomics and Metabolomics Shared Resource, Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Cristina M Furdui
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.,Proteomics and Metabolomics Shared Resource, Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Li Tan
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Mary L Bouxsein
- Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Virginia L Ferguson
- Department of Mechanical Engineering, University of Colorado At Boulder, Boulder, CO, USA
| | - Louis S Stodieck
- BioServe Space Technologies, Aerospace Engineering Sciences, University of Colorado At Boulder, Boulder, CO, USA
| | - David C Zawieja
- Department of Medical Physiology, Texas A&M University Medical School, Bryan, TX, USA
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Xiao W Mao
- Division of Biomedical Engineering Sciences (BMES), Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA
| | - Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA. .,Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| |
Collapse
|
5
|
Chen Z, Stanbouly S, Nishiyama NC, Chen X, Delp MD, Qiu H, Mao XW, Wang C. Spaceflight decelerates the epigenetic clock orchestrated with a global alteration in DNA methylome and transcriptome in the mouse retina. Precis Clin Med 2021; 4:93-108. [PMID: 34179686 PMCID: PMC8220224 DOI: 10.1093/pcmedi/pbab012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/27/2021] [Accepted: 05/13/2021] [Indexed: 01/30/2023] Open
Abstract
Astronauts exhibit an assortment of clinical abnormalities in their eyes during long-duration spaceflight. The purpose of this study was to determine whether spaceflight induces epigenomic and transcriptomic reprogramming in the retina or alters the epigenetic clock. The mice were flown for 37 days in animal enclosure modules on the International Space Station; ground-based control animals were maintained under similar housing conditions. Mouse retinas were isolated and both DNA methylome and transcriptome were determined by deep sequencing. We found that a large number of genes were differentially methylated with spaceflight, whereas there were fewer differentially expressed genes at the transcriptome level. Several biological pathways involved in retinal diseases such as macular degeneration were significantly altered. Our results indicated that spaceflight decelerated the retinal epigenetic clock. This study demonstrates that spaceflight impacts the retina at the epigenomic and transcriptomic levels, and such changes could be involved in the etiology of eye-related disorders among astronauts.
Collapse
Affiliation(s)
- Zhong Chen
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Seta Stanbouly
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Nina C Nishiyama
- Division of Radiation Research, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Xin Chen
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Michael D Delp
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL 32306, USA
| | - Hongyu Qiu
- Center for Molecular and Translational Medicine, Institute of Biomedical Science, Georgia State University, Atlanta, GA 30303, USA
| | - Xiao W Mao
- Division of Radiation Research, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Charles Wang
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| |
Collapse
|
6
|
Caldwell JT, Jones KMD, Park H, Pinto JR, Ghosh P, Reid-Foley EC, Ulrich B, Delp MD, Behnke BJ, Muller-Delp JM. Aerobic exercise training reduces cardiac function and coronary flow-induced vasodilation in mice lacking adiponectin. Am J Physiol Heart Circ Physiol 2021; 321:H1-H14. [PMID: 33989084 DOI: 10.1152/ajpheart.00885.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that adiponectin deficiency attenuates cardiac and coronary microvascular function and prevents exercise training-induced adaptations of the myocardium and the coronary microvasculature in adult mice. Adult wild-type (WT) or adiponectin knockout (adiponectin KO) mice underwent treadmill exercise training or remained sedentary for 8-10 wk. Systolic and diastolic functions were assessed before and after exercise training or cage confinement. Vasoreactivity of coronary resistance arteries was assessed at the end of exercise training or cage confinement. Before exercise training, ejection fraction and fractional shortening were similar in adiponectin KO and WT mice, but isovolumic contraction time was significantly lengthened in adiponectin KO mice. Exercise training increased ejection fraction (12%) and fractional shortening (20%) with no change in isovolumic contraction time in WT mice. In adiponectin KO mice, both ejection fraction (-9%) and fractional shortening (-12%) were reduced after exercise training and these decreases were coupled to a further increase in isovolumic contraction time (20%). In sedentary mice, endothelium-dependent dilation to flow was higher in arterioles from adiponectin KO mice as compared with WT mice. Exercise training enhanced dilation to flow in WT mice but decreased flow-induced dilation in adiponectin KO mice. These data suggest that compensatory mechanisms contribute to the maintenance of cardiac and coronary microvascular function in sedentary mice lacking adiponectin; however, in the absence of adiponectin, cardiac and coronary microvascular adaptations to exercise training are compromised.NEW & NOTEWORTHY We report that compensatory mechanisms contribute to the maintenance of cardiac and coronary microvascular function in sedentary mice in which adiponectin has been deleted; however, when mice lacking adiponectin are subjected to the physiological stress of exercise training, beneficial coronary microvascular and cardiac adaptations are compromised or absent.
Collapse
Affiliation(s)
- Jacob T Caldwell
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | | | - Hyerim Park
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, Florida
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - Payal Ghosh
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, Florida
| | - Emily C Reid-Foley
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - Brody Ulrich
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, Florida
| | - Brad J Behnke
- Department of Kinesiology, Johnson Cancer Research Center, Kansas State University, Manhattan, Kansas
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| |
Collapse
|
7
|
Willey JS, Britten RA, Blaber E, Tahimic CG, Chancellor J, Mortreux M, Sanford LD, Kubik AJ, Delp MD, Mao XW. The individual and combined effects of spaceflight radiation and microgravity on biologic systems and functional outcomes. J Environ Sci Health C Toxicol Carcinog 2021; 39:129-179. [PMID: 33902391 PMCID: PMC8274610 DOI: 10.1080/26896583.2021.1885283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Both microgravity and radiation exposure in the spaceflight environment have been identified as hazards to astronaut health and performance. Substantial study has been focused on understanding the biology and risks associated with prolonged exposure to microgravity, and the hazards presented by radiation from galactic cosmic rays (GCR) and solar particle events (SPEs) outside of low earth orbit (LEO). To date, the majority of the ground-based analogues (e.g., rodent or cell culture studies) that investigate the biology of and risks associated with spaceflight hazards will focus on an individual hazard in isolation. However, astronauts will face these challenges simultaneously Combined hazard studies are necessary for understanding the risks astronauts face as they travel outside of LEO, and are also critical for countermeasure development. The focus of this review is to describe biologic and functional outcomes from ground-based analogue models for microgravity and radiation, specifically highlighting the combined effects of radiation and reduced weight-bearing from rodent ground-based tail suspension via hind limb unloading (HLU) and partial weight-bearing (PWB) models, although in vitro and spaceflight results are discussed as appropriate. The review focuses on the skeletal, ocular, central nervous system (CNS), cardiovascular, and stem cells responses.
Collapse
Affiliation(s)
| | | | - Elizabeth Blaber
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | | | | | - Marie Mortreux
- Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center
| | - Larry D. Sanford
- Department of Radiation Oncology, Eastern Virginia Medical School
| | - Angela J. Kubik
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | - Michael D. Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University
| | - Xiao Wen Mao
- Division of Biomedical Engineering Sciences (BMES), Department of Basic Sciences, Loma Linda University
| |
Collapse
|
8
|
Mao XW, Nishiyama NC, Byrum SD, Stanbouly S, Jones T, Holley J, Sridharan V, Boerma M, Tackett AJ, Willey JS, Pecaut MJ, Delp MD. Spaceflight induces oxidative damage to blood-brain barrier integrity in a mouse model. FASEB J 2020; 34:15516-15530. [PMID: 32981077 PMCID: PMC8191453 DOI: 10.1096/fj.202001754r] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 12/18/2022]
Abstract
Many factors contribute to the health risks encountered by astronauts on missions outside Earth's atmosphere. Spaceflight-induced potential adverse neurovascular damage and late neurodegeneration are a chief concern. The goal of the present study was to characterize the effects of spaceflight on oxidative damage in the mouse brain and its impact on blood-brain barrier (BBB) integrity. Ten-week-old male C57BL/6 mice were launched to the International Space Station (ISS) for 35 days as part of Space-X 12 mission. Ground control (GC) mice were maintained on Earth in flight hardware cages. Within 38 ± 4 hours after returning from the ISS, mice were euthanized and brain tissues were collected for analysis. Quantitative assessment of brain tissue demonstrated that spaceflight caused an up to 2.2-fold increase in apoptosis in the hippocampus compared to the control group. Immunohistochemical analysis of the mouse brain revealed an increased expression of aquaporin4 (AQP4) in the flight hippocampus compared to the controls. There was also a significant increase in the expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) and a decrease in the expression of the BBB-related tight junction protein, Zonula occludens-1 (ZO-1). These results indicate a disturbance of BBB integrity. Quantitative proteomic analysis showed significant alterations in pathways responsible for neurovascular integrity, mitochondrial function, neuronal structure, protein/organelle transport, and metabolism in the brain after spaceflight. Changes in pathways associated with adhesion and molecular remodeling were also documented. These data indicate that long-term spaceflight may have pathological and functional consequences associated with neurovascular damage and late neurodegeneration.
Collapse
Affiliation(s)
- Xiao W Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Nina C Nishiyama
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
- Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Seta Stanbouly
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Tamako Jones
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Jacob Holley
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Alan J Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
- Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Michael J Pecaut
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, USA
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| |
Collapse
|
9
|
Tarasova OS, Kalenchuk VU, Borovik AS, Golubinskaya VO, Delp MD, Vinogradova OL. Simulated Microgravity Induces Regionally Distinct Neurovascular and Structural Remodeling of Skeletal Muscle and Cutaneous Arteries in the Rat. Front Physiol 2020; 11:675. [PMID: 32695017 PMCID: PMC7339929 DOI: 10.3389/fphys.2020.00675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/26/2020] [Indexed: 01/10/2023] Open
Abstract
Introduction: Mechanical forces and sympathetic influences are key determinants of vascular structure and function. This study tested the hypothesis that hindlimb unloading (HU) exerts diverse effects on forelimb and hindlimb small arteries of rats in functionally different regions of the skeletal muscle and skin. Methods: Male Wistar rats were subjected to HU for 2 weeks, then skeletal muscle arteries (deep brachial and sural) and skin arteries (median and saphenous) were examined in vitro using wire myography or isobaric perfusion and glyoxylic acid staining. Results: HU increased lumen diameter of both forelimb arteries but decreased diameter of the sural artery; the saphenous artery diameter was not affected. Following HU, maximal contractile responses to noradrenaline and serotonin increased in the forelimb but decreased in the hindlimb skeletal muscle feed arteries with no change in skin arteries; all region-specific alterations persisted after endothelium removal. HU increased the sensitivity to vasoconstrictors in the saphenous artery but not in the sural artery. In the saphenous artery, initially high sympathetic innervation density was reduced by HU, sparse innervation in the sural artery was not affected. Electrical stimulation of periarterial sympathetic nerves in isobarically perfused segments of the saphenous artery demonstrated a two-fold decrease of the contractile responses in HU rats compared to that of controls. Conclusion: HU induces contrasting structural and functional adaptations in forelimb and hindlimb skeletal muscle arteries. Additionally, HU had diverse effects in two hindlimb vascular regions. Hyper-sensitivity of the saphenous artery to vasoconstrictors appears to result from the shortage of trophic sympathetic influence. Importantly, HU impaired sympathetically induced arterial vasoconstriction, consistent with the decreased sympathetic constrictor response in humans following space flight.
Collapse
Affiliation(s)
- Olga S Tarasova
- State Research Center of the Russian Federation, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | | | - Anatoly S Borovik
- State Research Center of the Russian Federation, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | | | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, Florida State University, Tallahassee, FL, United States
| | - Olga L Vinogradova
- State Research Center of the Russian Federation, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
- Faculty of Basic Medicine, M.V. Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
10
|
Kwok A, Rosas S, Bateman TA, Livingston E, Smith TL, Moore J, Zawieja DC, Hampton T, Mao XW, Delp MD, Willey JS. Altered rodent gait characteristics after ~35 days in orbit aboard the International Space Station. Life Sci Space Res (Amst) 2020; 24:9-17. [PMID: 31987483 DOI: 10.1016/j.lssr.2019.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/23/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
The long-term adaptations to microgravity and other spaceflight challenges within the confines of a spacecraft, and readaptations to weight-bearing upon reaching a destination, are unclear. While post-flight gait change in astronauts have been well documented and reflect multi-system deficits, no data from rodents have been collected. Thus, the purpose of this study was to evaluate gait changes in response to spaceflight. A prospective collection of gait data was collected on 3 groups of mice: those who spent~35 days in orbit (FLIGHT) aboard the International Space Station (ISS); a ground-based control with the same habitat conditions as ISS (Ground Control; GC); and a vivarium control with typical rodent housing conditions (VIV). Pre-flight and post-flight gait measurements were conducted utilizing an optimized and portable gait analysis system (DigiGait, Mouse Specifics, Inc). The total data acquisition time for gait patterns of FLIGHT and control mice was 1.5-5 min/mouse, allowing all 20 mice per group to be assessed in less than an hour. Patterns of longitudinal gait changes were observed in the hind limbs and the forelimbs of the FLIGHT mice after ~35 days in orbit; few differences were observed in gait characteristics within the GC and VIV controls from the initial to the final gait assessment, and between groups. For FLIGHT mice, 12 out of 18 of the evaluated gait characteristics in the hind limbs were significantly changed, including: stride width variability; stride length and variance; stride, swing, and stance duration; paw angle and area at peak stance; and step angle, among others. Gait characteristics that decreased included stride frequency, and others. Moreover, numerous forelimb gait characteristics in the FLIGHT mice were changed at post-flight measures relative to pre-flight. This rapid DigiGait gait measurement tool and customized spaceflight protocol is useful for providing preliminary insight into how spaceflight could affect multiple systems in rodents in which deficits are reflected by altered gait characteristics.
Collapse
Affiliation(s)
- Andy Kwok
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Samuel Rosas
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, United States; Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Ted A Bateman
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Eric Livingston
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Thomas L Smith
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Joseph Moore
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - David C Zawieja
- Department of Medical Physiology, Texas A&M University, College Station, TX, United States
| | - Tom Hampton
- Mouse Specifics, Framingham, MA, United States
| | - Xiao W Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA, United States
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, United States
| | - Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, United States.
| |
Collapse
|
11
|
Overbey EG, da Silveira WA, Stanbouly S, Nishiyama NC, Roque-Torres GD, Pecaut MJ, Zawieja DC, Wang C, Willey JS, Delp MD, Hardiman G, Mao XW. Spaceflight influences gene expression, photoreceptor integrity, and oxidative stress-related damage in the murine retina. Sci Rep 2019; 9:13304. [PMID: 31527661 PMCID: PMC6746706 DOI: 10.1038/s41598-019-49453-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/19/2019] [Indexed: 11/08/2022] Open
Abstract
Extended spaceflight has been shown to adversely affect astronaut visual acuity. The purpose of this study was to determine whether spaceflight alters gene expression profiles and induces oxidative damage in the retina. Ten week old adult C57BL/6 male mice were flown aboard the ISS for 35 days and returned to Earth alive. Ground control mice were maintained on Earth under identical environmental conditions. Within 38 (+/-4) hours after splashdown, mice ocular tissues were collected for analysis. RNA sequencing detected 600 differentially expressed genes (DEGs) in murine spaceflight retinas, which were enriched for genes related to visual perception, the phototransduction pathway, and numerous retina and photoreceptor phenotype categories. Twelve DEGs were associated with retinitis pigmentosa, characterized by dystrophy of the photoreceptor layer rods and cones. Differentially expressed transcription factors indicated changes in chromatin structure, offering clues to the observed phenotypic changes. Immunofluorescence assays showed degradation of cone photoreceptors and increased retinal oxidative stress. Total retinal, retinal pigment epithelium, and choroid layer thickness were significantly lower after spaceflight. These results indicate that retinal performance may decrease over extended periods of spaceflight and cause visual impairment.
Collapse
Affiliation(s)
- Eliah G Overbey
- University of Washington, Department of Genome Sciences, Seattle, WA, USA.
| | - Willian Abraham da Silveira
- Queen's University Belfast, Faculty of Medicine, Health and Life Sciences, School of Biological Sciences, Institute for Global Food Security (IGFS), 19 Chlorine Gardens, Belfast, Northern Ireland, BT9 5DL, UK
| | - Seta Stanbouly
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, 92350, USA
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Nina C Nishiyama
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, 92350, USA
| | | | - Michael J Pecaut
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, 92350, USA
| | - David Carl Zawieja
- Department of Medical Physiology, Texas A&M University, College Station, Texas, USA
| | - Charles Wang
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, 32306, USA
| | - Gary Hardiman
- Queen's University Belfast, Faculty of Medicine, Health and Life Sciences, School of Biological Sciences, Institute for Global Food Security (IGFS), 19 Chlorine Gardens, Belfast, Northern Ireland, BT9 5DL, UK
| | - Xiao Wen Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, 92350, USA
| |
Collapse
|
12
|
Mao XW, Byrum S, Nishiyama NC, Pecaut MJ, Sridharan V, Boerma M, Tackett AJ, Shiba D, Shirakawa M, Takahashi S, Delp MD. Impact of Spaceflight and Artificial Gravity on the Mouse Retina: Biochemical and Proteomic Analysis. Int J Mol Sci 2018; 19:E2546. [PMID: 30154332 PMCID: PMC6165321 DOI: 10.3390/ijms19092546] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/23/2022] Open
Abstract
Astronauts are reported to have experienced some impairment in visual acuity during their mission on the International Space Station (ISS) and after they returned to Earth. There is emerging evidence that changes in vision may involve alterations in ocular structure and function. To investigate possible mechanisms, changes in protein expression profiles and oxidative stress-associated apoptosis were examined in mouse ocular tissue after spaceflight. Nine-week-old male C57BL/6 mice (n = 12) were launched from the Kennedy Space Center on a SpaceX rocket to the ISS for a 35-day mission. The animals were housed in the mouse Habitat Cage Unit (HCU) in the Japan Aerospace Exploration Agency (JAXA) "Kibo" facility on the ISS. The flight mice lived either under an ambient microgravity condition (µg) or in a centrifugal habitat unit that produced 1 g artificial gravity (µg + 1 g). Habitat control (HC) and vivarium control mice lived on Earth in HCUs or normal vivarium cages, respectively. Quantitative assessment of ocular tissue demonstrated that the µg group induced significant apoptosis in the retina vascular endothelial cells compared to all other groups (p < 0.05) that was 64% greater than that in the HC group. Proteomic analysis showed that many key pathways responsible for cell death, cell repair, inflammation, and metabolic stress were significantly altered in µg mice compared to HC animals. Additionally, there were more significant changes in regulated protein expression in the µg group relative to that in the µg + 1 g group. These data provide evidence that spaceflight induces retinal apoptosis of vascular endothelial cells and changes in retinal protein expression related to cellular structure, immune response and metabolic function, and that artificial gravity (AG) provides some protection against these changes. These retinal cellular responses may affect blood⁻retinal barrier (BRB) integrity, visual acuity, and impact the potential risk of developing late retinal degeneration.
Collapse
Affiliation(s)
- Xiao W Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA 92350, USA.
| | - Stephanie Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA..
- Arkansas Children's Research Institute, Little Rock, AR 72202, USA.
| | - Nina C Nishiyama
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA 92350, USA.
| | - Michael J Pecaut
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University School of Medicine and Medical Center, Loma Linda, CA 92350, USA.
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Alan J Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA..
- Arkansas Children's Research Institute, Little Rock, AR 72202, USA.
| | - Dai Shiba
- JEM Utilization Center, Human Spaceflight Technology Directorate, JAXA, Tsukuba 305-8505, Japan.
| | - Masaki Shirakawa
- JEM Utilization Center, Human Spaceflight Technology Directorate, JAXA, Tsukuba 305-8505, Japan.
| | - Satoru Takahashi
- Department of Anatomy and Embryology, University of Tsukuba, Tsukuba 305-8575, Japan.
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306, USA.
| |
Collapse
|
13
|
Evanson KW, Goldsmith JA, Ghosh P, Delp MD. The G protein-coupled estrogen receptor agonist, G-1, attenuates BK channel activation in cerebral arterial smooth muscle cells. Pharmacol Res Perspect 2018; 6:e00409. [PMID: 29938113 PMCID: PMC6011940 DOI: 10.1002/prp2.409] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 05/22/2018] [Indexed: 11/07/2022] Open
Abstract
The G protein-coupled estrogen receptor (GPER) is a significant modulator of arterial contractility and blood flow. The GPER-specific activator, G-1, has been widely used to characterize GPER function in a variety of tissue types. Large conductance, calcium (Ca2+)-activated K+ (BK) channels are sensitive to 17β-estradiol (17β-E2) and estrogenic compounds (e.g., tamoxifen, ICI 182 780) that target estrogen receptors. The purpose of this study was to investigate the effects of G-1 on BK channel activation and function in cerebral arterial myocytes. Inside-out and perforated patch clamp were utilized to assess the effects of G-1 (50 nmol·L-1-5 μmol·L-1) on BK channel activation and currents in cerebral arterial myocytes. Pressurized artery myography was used to investigate the effects of G-1 on vasodilatory response and BK channel function of cerebral resistance size arteries. G-1 reduced BK channel activation in cerebral arterial myocytes through elevations in BK channel mean close times. Depressed BK channel activation following G-1 application resulted in attenuated physiological BK currents (transient BK currents). G-1 elicited vasodilation, but reduced BK channel function, in pressurized, endothelium-denuded cerebral arteries. These data suggest that G-1 directly suppresses BK channel activation and currents in cerebral arterial myocytes, BK channels being critically important in the regulation of myocyte membrane potential and arterial contractility. Thus, GPER-mediated vasodilation using G-1 to activate the receptor may underestimate the physiological function and relevance of GPER in the cardiovascular system.
Collapse
Affiliation(s)
- Kirk W. Evanson
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Jacob A. Goldsmith
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Payal Ghosh
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Michael D. Delp
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| |
Collapse
|
14
|
Muller-Delp JM, Hotta K, Chen B, Behnke BJ, Maraj JJ, Delp MD, Lucero TR, Bramy JA, Alarcon DB, Morgan HE, Cowan MR, Haynes AD. Effects of age and exercise training on coronary microvascular smooth muscle phenotype and function. J Appl Physiol (1985) 2017; 124:140-149. [PMID: 29025901 DOI: 10.1152/japplphysiol.00459.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Coronary microvascular function and blood flow responses during acute exercise are impaired in the aged heart but can be restored by exercise training. Coronary microvascular resistance is directly dependent on vascular smooth muscle function in coronary resistance arterioles; therefore, we hypothesized that age impairs contractile function and alters the phenotype of vascular smooth muscle in coronary arterioles. We further hypothesized that exercise training restores contractile function and reverses age-induced phenotypic alterations of arteriolar smooth muscle. Young and old Fischer 344 rats underwent 10 wk of treadmill exercise training or remained sedentary. At the end of training or cage confinement, contractile responses, vascular smooth muscle proliferation, and expression of contractile proteins were assessed in isolated coronary arterioles. Both receptor- and non-receptor-mediated contractile function were impaired in coronary arterioles from aged rats. Vascular smooth muscle shifted from a differentiated, contractile phenotype to a secretory phenotype with associated proliferation of smooth muscle in the arteriolar wall. Expression of smooth muscle myosin heavy chain 1 (SM1) was decreased in arterioles from aged rats, whereas expression of phospho-histone H3 and of the synthetic protein ribosomal protein S6 (rpS6) were increased. Exercise training improved contractile responses, reduced smooth muscle proliferation and expression of rpS6, and increased expression of SM1 in arterioles from old rats. Thus age-induced contractile dysfunction of coronary arterioles and emergence of a secretory smooth muscle phenotype may contribute to impaired coronary blood flow responses, but arteriolar contractile responsiveness and a younger smooth muscle phenotype can be restored with late-life exercise training. NEW & NOTEWORTHY Aging impairs contractile function of coronary arterioles and induces a shift of the vascular smooth muscle toward a proliferative, noncontractile phenotype. Late-life exercise training reverses contractile dysfunction of coronary arterioles and restores a young phenotype to the vascular smooth muscle.
Collapse
Affiliation(s)
- Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Kazuki Hotta
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Bei Chen
- Department of Physiology and Functional Genomics, University of Florida , Gainesville, Florida
| | - Bradley J Behnke
- Department of Kinesiology and Johnson Cancer Research Center, Kansas State University , Manhattan, Kansas
| | - Joshua J Maraj
- Department of Physiology and Functional Genomics, University of Florida , Gainesville, Florida
| | - Michael D Delp
- Department of Nutrition, Food & Exercise Sciences, Florida State University , Tallahassee, Florida
| | - Tiffani R Lucero
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Jeremy A Bramy
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - David B Alarcon
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Hannah E Morgan
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Morgan R Cowan
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| | - Anthony D Haynes
- Department of Biomedical Sciences, Florida State University , Tallahassee, Florida
| |
Collapse
|
15
|
Hotta K, Chen B, Behnke BJ, Ghosh P, Stabley JN, Bramy JA, Sepulveda JL, Delp MD, Muller-Delp JM. Exercise training reverses age-induced diastolic dysfunction and restores coronary microvascular function. J Physiol 2017; 595:3703-3719. [PMID: 28295341 PMCID: PMC5471361 DOI: 10.1113/jp274172] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 02/20/2017] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS In a rat model of ageing that is free of atherosclerosis or hypertension, E/A, a diagnostic measure of diastolic filling, decreases, and isovolumic relaxation time increases, indicating that both active and passive ventricular relaxation are impaired with advancing age. Resting coronary blood flow and coronary functional hyperaemia are reduced with age, and endothelium-dependent vasodilatation declines with age in coronary resistance arterioles. Exercise training reverses age-induced declines in diastolic and coronary microvascular function. Thus, microvascular dysfunction and inadequate coronary perfusion are likely mechanisms of diastolic dysfunction in aged rats. Exercise training, initiated at an advanced age, reverses age-related diastolic and microvascular dysfunction; these data suggest that late-life exercise training can be implemented to improve coronary perfusion and diastolic function in the elderly. ABSTRACT The risk for diastolic dysfunction increases with advancing age. Regular exercise training ameliorates age-related diastolic dysfunction; however, the underlying mechanisms have not been identified. We investigated whether (1) microvascular dysfunction contributes to the development of age-related diastolic dysfunction, and (2) initiation of late-life exercise training reverses age-related diastolic and microvascular dysfunction. Young and old rats underwent 10 weeks of exercise training or remained as sedentary, cage-controls. Isovolumic relaxation time (IVRT), early diastolic filling (E/A), myocardial performance index (MPI) and aortic stiffness (pulse wave velocity; PWV) were evaluated before and after exercise training or cage confinement. Coronary blood flow and vasodilatory responses of coronary arterioles were evaluated in all groups at the end of training. In aged sedentary rats, compared to young sedentary rats, a 42% increase in IVRT, a 64% decrease in E/A, and increased aortic stiffness (PWV: 6.36 ± 0.47 vs.4.89 ± 0.41, OSED vs. YSED, P < 0.05) was accompanied by impaired coronary blood flow at rest and during exercise. Endothelium-dependent vasodilatation was impaired in coronary arterioles from aged rats (maximal relaxation to bradykinin: 56.4 ± 5.1% vs. 75.3 ± 5.2%, OSED vs. YSED, P < 0.05). After exercise training, IVRT, a measure of active ventricular relaxation, did not differ between old and young rats. In old rats, exercise training reversed the reduction in E/A, reduced aortic stiffness, and eliminated impairment of coronary blood flow responses and endothelium-dependent vasodilatation. Thus, age-related diastolic and microvascular dysfunction are reversed by late-life exercise training. The restorative effect of exercise training on coronary microvascular function may result from improved endothelial function.
Collapse
Affiliation(s)
- Kazuki Hotta
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Bei Chen
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | - Bradley J Behnke
- Department of Kinesiology & Johnson Cancer Research Center, Kansas State University, Manhattan, KS, USA
| | - Payal Ghosh
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - John N Stabley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeremy A Bramy
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Jaime L Sepulveda
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| |
Collapse
|
16
|
Delp MD, Charvat JM, Limoli CL, Globus RK, Ghosh P. Apollo Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep Space Radiation Effects on the Vascular Endothelium. Sci Rep 2016; 6:29901. [PMID: 27467019 PMCID: PMC4964660 DOI: 10.1038/srep29901] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/22/2016] [Indexed: 01/30/2023] Open
Abstract
As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth's protective magnetosphere into the more intense deep space radiation environment. The primary purpose of this study was to determine whether mortality rates due to cardiovascular disease (CVD), cancer, accidents and all other causes of death differ in (1) astronauts who never flew orbital missions in space, (2) astronauts who flew only in low Earth orbit (LEO), and (3) Apollo lunar astronauts, the only humans to have traveled beyond Earth's magnetosphere. Results show there were no differences in CVD mortality rate between non-flight (9%) and LEO (11%) astronauts. However, the CVD mortality rate among Apollo lunar astronauts (43%) was 4-5 times higher than in non-flight and LEO astronauts. To test a possible mechanistic basis for these findings, a secondary purpose was to determine the long-term effects of simulated weightlessness and space-relevant total-body irradiation on vascular responsiveness in mice. The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction. Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD among astronauts exposed to deep space radiation.
Collapse
Affiliation(s)
- Michael D. Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Jacqueline M. Charvat
- Wyle Science, Technology and Engineering Group, Johnson Space Center, Houston TX 77058, USA
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California Irvine, Irvine, CA 92697, USA
| | - Ruth K. Globus
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Payal Ghosh
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306, USA
| |
Collapse
|
17
|
Ghosh P, Behnke BJ, Stabley JN, Kilar CR, Park Y, Narayanan A, Alwood JS, Shirazi-Fard Y, Schreurs AS, Globus RK, Delp MD. Effects of High-LET Radiation Exposure and Hindlimb Unloading on Skeletal Muscle Resistance Artery Vasomotor Properties and Cancellous Bone Microarchitecture in Mice. Radiat Res 2016; 185:257-66. [PMID: 26930379 DOI: 10.1667/rr4308.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Weightlessness during spaceflight leads to functional changes in resistance arteries and loss of cancellous bone, which may be potentiated by radiation exposure. The purpose of this study was to assess the effects of hindlimb unloading (HU) and total-body irradiation (TBI) on the vasomotor responses of skeletal muscle arteries. Male C57BL/6 mice were assigned to control, HU (13-16 days), TBI (1 Gy (56)Fe, 600 MeV, 10 cGy/min) and HU-TBI groups. Gastrocnemius muscle feed arteries were isolated for in vitro study. Endothelium-dependent (acetylcholine) and -independent (Dea-NONOate) vasodilator and vasoconstrictor (KCl, phenylephrine and myogenic) responses were evaluated. Arterial endothelial nitric oxide synthase (eNOS), superoxide dismutase-1 (SOD-1) and xanthine oxidase (XO) protein content and tibial cancellous bone microarchitecture were quantified. Endothelium-dependent and -independent vasodilator responses were impaired in all groups relative to control, and acetylcholine-induced vasodilation was lower in the HU-TBI group relative to that in the HU and TBI groups. Reductions in endothelium-dependent vasodilation correlated with a lower cancellous bone volume fraction. Nitric oxide synthase inhibition abolished all group differences in endothelium-dependent vasodilation. HU and HU-TBI resulted in decreases in eNOS protein levels, while TBI and HU-TBI produced lower SOD-1 and higher XO protein content. Vasoconstrictor responses were not altered. Reductions in NO bioavailability (eNOS), lower anti-oxidant capacity (SOD-1) and higher pro-oxidant capacity (XO) may contribute to the deficits in NOS signaling in skeletal muscle resistance arteries. These findings suggest that the combination of insults experienced in spaceflight leads to impairment of vasodilator function in resistance arteries that is mediated through deficits in NOS signaling.
Collapse
Affiliation(s)
- Payal Ghosh
- a Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida 32306
| | - Brad J Behnke
- b Department of Kinesiology and the Johnson Cancer Research Center, Kansas State University, Manhattan, Kansas 66506
| | - John N Stabley
- c Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Cody R Kilar
- d Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida 32611
| | - Yoonjung Park
- e Department of Health and Human Performance, University of Houston, Houston, Texas 77204
| | - Anand Narayanan
- f Department of Medical Physiology, Texas A&M University Health Science Center, Bryan, Texas 77807; and
| | - Joshua S Alwood
- g Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035
| | - Yasaman Shirazi-Fard
- g Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035
| | - Ann-Sofie Schreurs
- g Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035
| | - Ruth K Globus
- g Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035
| | - Michael D Delp
- a Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida 32306
| |
Collapse
|
18
|
Ghosh P, Stabley JN, Behnke BJ, Allen MR, Delp MD. Effects of spaceflight on the murine mandible: Possible factors mediating skeletal changes in non-weight bearing bones of the head. Bone 2016; 83:156-161. [PMID: 26545335 DOI: 10.1016/j.bone.2015.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 11/01/2015] [Accepted: 11/02/2015] [Indexed: 11/22/2022]
Abstract
Spaceflight-induced remodeling of the skull is characterized by greater bone volume, mineral density, and mineral content. To further investigate the effects of spaceflight on other non-weight bearing bones of the head, as well as to gain insight into potential factors mediating the remodeling of the skull, the purpose of the present study was to determine the effects of spaceflight on mandibular bone properties. Female C57BL/6 mice were flown 15d on the STS-131 Space Shuttle mission (n=8) and 13d on the STS-135 mission (n=5) or remained as ground controls (GC). Upon landing, mandibles were collected and analyzed via micro-computed tomography for tissue mineralization, bone volume (BV/TV), and distance from the cemento-enamel junction to the alveolar crest (CEJ-AC). Mandibular mineralization was not different between spaceflight (SF) and GC mice for either the STS-131 or STS-135 missions. Mandibular BV/TV (combined cortical and trabecular bone) was lower in mandibles from SF mice on the STS-131 mission (80.7±0.8%) relative to that of GC (n=8) animals (84.2±1.2%), whereas BV/TV from STS-135 mice was not different from GC animals (n=7). The CEJ-AC distance was shorter in mandibles from STS-131 mice (0.217±0.004mm) compared to GC animals (0.283±0.009mm), indicating an anabolic (or anti-catabolic) effect of spaceflight, while CEJ-AC distance was similar between STS-135 and GC mice. These findings demonstrate that mandibular bones undergo skeletal changes during spaceflight and are susceptible to the effects of weightlessness. However, adaptation of the mandible to spaceflight is dissimilar to that of the cranium, at least in terms of changes in BV/TV.
Collapse
Affiliation(s)
- Payal Ghosh
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, FL 32306, USA
| | - John N Stabley
- Sanford-Burnham Medical Research Institute, Orlando, FL 3282, USA
| | - Bradley J Behnke
- Department of Kinesiology and Johnson Cancer Research Center, Kansas State University, Manhattan, KS 66506, USA
| | - Matthew R Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, FL 32306, USA.
| |
Collapse
|
19
|
Affiliation(s)
- Michael D. Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
| | | | - Olga S. Tarasova
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; and
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
20
|
Prisby RD, Alwood JS, Behnke BJ, Stabley JN, McCullough DJ, Ghosh P, Globus RK, Delp MD. Effects of hindlimb unloading and ionizing radiation on skeletal muscle resistance artery vasodilation and its relation to cancellous bone in mice. J Appl Physiol (1985) 2015; 120:97-106. [PMID: 26472865 DOI: 10.1152/japplphysiol.00423.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 10/08/2015] [Indexed: 01/10/2023] Open
Abstract
Spaceflight has profound effects on vascular function as a result of weightlessness that may be further compounded by radiation exposure. The purpose of the present study was to assess the individual and combined effects of hindlimb unloading (HU) and radiation (Rad) on vasodilator responses in the skeletal muscle vasculature. Adult male C57BL/6J mice were randomized to one of four groups: control (Con), HU (tail suspension for 15 days), Rad (200 cGy of (137)Cs), and HU-Rad (15-day tail suspension and 200 cGy of (137)Cs). Endothelium-dependent vasodilation of gastrocnemius feed arteries was assessed in vitro using acetylcholine (ACh, 10(-9)-10(-4) M) and inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX). Endothelium-independent vasodilation was assessed using Dea-NONOate (10(-9)-10(-4) M). Endothelium-dependent and -independent vasodilator responses were impaired relative to Con responses in all treatment groups; however, there was no further impairment from the combination of treatments (HU-Rad) relative to that in the HU and Rad groups. The NOS-mediated contribution to endothelium-dependent vasodilation was depressed with HU and Rad. This impairment in NOS signaling may have been partially compensated for by an enhancement of PGI2-mediated dilation. Changes in endothelium-dependent vasodilation were also associated with decrements in trabecular bone volume in the proximal tibia metaphysis. These data demonstrate that the simulated space environment (i.e., radiation exposure and unloading of muscle and bone) significantly impairs skeletal muscle artery vasodilation, mediated through endothelium-dependent reductions in NOS signaling and decrements in vascular smooth muscle cell responsiveness to NO.
Collapse
Affiliation(s)
- Rhonda D Prisby
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Joshua S Alwood
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, California
| | - Brad J Behnke
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida; Department of Kinesiology and the Johnson Cancer Research Center, Kansas State University, Manhattan, Kansas; and
| | - John N Stabley
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida
| | - Danielle J McCullough
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida
| | - Payal Ghosh
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida; Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
| | - Ruth K Globus
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, California
| | - Michael D Delp
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida; Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
| |
Collapse
|
21
|
Abstract
INTRODUCTION The principal nutrient artery to the femur demonstrates an increase in nitric oxide-mediated vasodilation in rats after treadmill exercise training. The present study sought to determine whether exercise training improves hindlimb bone and marrow blood flow distribution at rest and during exercise. METHODS Six 8-month old male Sprague-Dawley rats were exercise trained (ET) with treadmill walking at 15 m · min(-1) up a 15° incline for 60 min · d(-1) over a 10- to 12-wk period. Sedentary (SED) control animals were acclimated to treadmill exercise for 5 min · d(-1) during the week preceding the blood flow measurements. Blood flow to nine distinct regions of the femur, tibia, and fibula was determined at rest and during low-intensity exercise (15 m · min(-1) walking, 0° incline) using the reference sample microsphere method. RESULTS The results demonstrate an augmentation of exercise hyperemia above that observed in SED rats during exercise in only one region of the bone, the femoral diaphysis, of ET rats. However, whereas exercise hyperemia occurred in three of the nine hindlimb bone regions measured in SED rats, exercise hyperemia occurred in seven of nine regions in ET rats. CONCLUSIONS These data indicate an increase in generalized hindlimb bone and marrow blood flow during physical activity after a period of exercise training. Elevations in regional bone and marrow blood flow after training may augment medullary pressure and bone interstitial fluid flow, thus benefiting bone integrity.
Collapse
Affiliation(s)
- John N Stabley
- 1Center for Exercise Science, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL; and 2Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL
| | | | | | | |
Collapse
|
22
|
Abstract
Bone health and cardiovascular function are compromised in individuals with type 2 diabetes mellitus (T2DM). The purpose of this study was to determine whether skeletal vascular control mechanisms are altered during the progression of T2DM in Zucker diabetic fatty (ZDF) rats. Responses of the principal nutrient artery (PNA) of the femur from obese ZDF rats with prediabetes, short-term diabetes, and long-term diabetes to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) vasodilation and potassium chloride, norepinephrine (NE), and a myogenic vasoconstrictor were determined in vitro. Few changes in the PNA vasomotor responses occurred for the prediabetic and short-term diabetic conditions. Endothelium-dependent and -independent vasodilation were reduced, and NE and myogenic vasoconstriction were increased in obese ZDF rats with long-term diabetes relative to lean age-matched controls. Differences in endothelium-dependent vasodilation of the femoral PNA between ZDF rats and controls were abolished by the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester. The passive pressure-diameter response of the femoral PNA was also lower across a range of intraluminal pressures with long-term T2DM. Regional bone and marrow perfusion and vascular conductance, measured in vivo using radiolabeled microspheres, were lower in obese ZDF rats with long-term diabetes. These findings indicate that the profound impairment of the bone circulation may contribute to the osteopenia found to occur in long bones during chronic T2DM.
Collapse
Affiliation(s)
- John N Stabley
- Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA
| | - Rhonda D Prisby
- Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA
| | - Bradley J Behnke
- Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA
| | - Michael D Delp
- Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA Department of Applied Physiology and KinesiologyUniversity of Florida, Gainesville, Florida 32611, USADepartment of Kinesiology and Applied PhysiologyUniversity of Delaware, Newark, Delaware 19713, USADepartment of KinesiologyKansas State University, Manhattan, Kansas 66506, USADepartment of NutritionFood and Exercise Science, College of Human Sciences, Florida State University, 242 Sandels Building, 120 Convocation Way, Tallahassee, Florida 32306, USA
| |
Collapse
|
23
|
Sofronova SI, Tarasova OS, Gaynullina D, Borzykh AA, Behnke BJ, Stabley JN, McCullough DJ, Maraj JJ, Hanna M, Muller-Delp JM, Vinogradova OL, Delp MD. Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice. J Appl Physiol (1985) 2015; 118:830-8. [PMID: 25593287 PMCID: PMC4385880 DOI: 10.1152/japplphysiol.00976.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/13/2015] [Indexed: 01/03/2023] Open
Abstract
Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) (n = 6), habitat control (HC) (n = 6), and vivarium control (VC) (n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca(2+) mechanism (30-80 mM KCl) and thromboxane A2 receptors (10(-8) - 3 × 10(-5) M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress.
Collapse
Affiliation(s)
- Svetlana I Sofronova
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University
| | - Olga S Tarasova
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University
| | - Dina Gaynullina
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University; Department of Physiology, Russian National Research Medical University, Moscow, Russia
| | - Anna A Borzykh
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow
| | - Bradley J Behnke
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - John N Stabley
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Danielle J McCullough
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Joshua J Maraj
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Mina Hanna
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida; and
| | | | - Michael D Delp
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida; Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
| |
Collapse
|
24
|
Ghosh P, Mora Solis FR, Dominguez JM, Spier SA, Donato AJ, Delp MD, Muller-Delp JM. Exercise training reverses aging-induced impairment of myogenic constriction in skeletal muscle arterioles. J Appl Physiol (1985) 2015; 118:904-11. [PMID: 25634999 DOI: 10.1152/japplphysiol.00277.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 01/26/2015] [Indexed: 12/16/2022] Open
Abstract
To investigate whether exercise training can reverse age-related impairment of myogenic vasoconstriction in skeletal muscle arterioles, young (4 mo) and old (22 mo) male Fischer 344 rats were randomly assigned to either sedentary or exercise-trained groups. The roles of the endothelium and Kv1 channels in age- and exercise training-induced adaptations of myogenic responses were assessed through evaluation of pressure-induced constriction in endothelium-intact and denuded soleus muscle arterioles in the presence and absence of the Kv1 channel blocker, correolide. Exercise training enhanced myogenic constriction in arterioles from both old and young rats. In arterioles from old rats, exercise training restored myogenic constriction to a level similar to that of arterioles from young sedentary rats. Removal of the endothelium did not alter myogenic constriction of arterioles from young sedentary rats, but reduced myogenic constriction in arterioles from young exercise-trained rats. In contrast, endothelial removal had no effect on myogenic constriction of arterioles from old exercise-trained rats, but increased myogenic vasoconstriction in old sedentary rats. The effect of Kv1 channel blockade was also dependent on age and training status. In arterioles from young sedentary rats, Kv1 blockade had little effect on myogenic constriction, whereas in old sedentary rats Kv1 blockade increased myogenic constriction. After exercise training, Kv1 channel blockade increased myogenic constriction in arterioles from both young and old rats. Thus exercise training restores myogenic constriction of arterioles from old rats and enhances myogenic constriction from young rats through adaptations of the endothelium and smooth muscle Kv1 channels.
Collapse
Affiliation(s)
- Payal Ghosh
- Departments of Applied Physiology and Kinesiology and
| | | | - James M Dominguez
- Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Scott A Spier
- Department of Health and Kinesiology, University of Texas at Tyler, Texas
| | - Anthony J Donato
- Department of Internal Medicine and Veteran's Affairs Medical Center, Geriatrics Research Education and Clinical Center, University of Utah, Salt Lake City, Utah
| | - Michael D Delp
- Department of Nutrition, Food and Exercise Sciences, and the Center for Advancing Exercise and Nutrition Research on Aging, Florida State University, Tallahassee, Florida; and
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University College of Medicine, Florida State University, Tallahassee, Florida
| |
Collapse
|
25
|
Prisby RD, Behnke BJ, Allen MR, Delp MD. Effects of skeletal unloading on the vasomotor properties of the rat femur principal nutrient artery. J Appl Physiol (1985) 2015; 118:980-8. [PMID: 25635000 DOI: 10.1152/japplphysiol.00576.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/26/2015] [Indexed: 11/22/2022] Open
Abstract
Spaceflight and prolonged bed rest induce deconditioning of the cardiovascular system and bone loss. Previous research has shown declines in femoral bone and marrow perfusion during unloading and with subsequent reloading in hindlimb-unloaded (HU) rats, an animal model of chronic disuse. We hypothesized that the attenuated bone and marrow perfusion may result from altered vasomotor properties of the bone resistance vasculature. Therefore, the purpose of this study was to determine the effects of unloading on the vasoconstrictor and vasodilator properties of the femoral principal nutrient artery (PNA), the main conduit for blood flow to the femur, in 2 wk HU and control (CON) rats. Vasoconstriction of the femoral PNA was assessed in vitro using norepinephrine, phenylephrine, clonidine, KCl, endothelin-1, arginine vasopressin, and myogenic responsiveness. Vasodilation through endothelium-dependent [acetylcholine, bradykinin, and flow-mediated dilation (FMD)] and endothelium-independent mechanisms [sodium nitroprusside (SNP) and adenosine] were also determined. Vasoconstrictor responsiveness of the PNA from HU rats was not enhanced through any of the mechanisms tested. Endothelium-dependent vasodilation to acetylcholine (CON, 86 ± 3%; HU, 48 ± 7% vasodilation) and FMD (CON, 61 ± 9%; HU, 11 ± 11% vasodilation) were attenuated in PNAs from HU rats, while responses to bradykinin were not different between groups. Endothelium-independent vasodilation to SNP and adenosine were not different between groups. These data indicate that unloading-induced decrements in bone and marrow perfusion and increases in vascular resistance are not the result of enhanced vasoconstrictor responsiveness of the bone resistance arteries but are associated with reductions in endothelium-dependent vasodilation.
Collapse
Affiliation(s)
- Rhonda D Prisby
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Bradley J Behnke
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, Florida; Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Matthew R Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Michael D Delp
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, Florida; Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, Florida
| |
Collapse
|
26
|
Hanna MA, Taylor CR, Chen B, La HS, Maraj JJ, Kilar CR, Behnke BJ, Delp MD, Muller-Delp JM. Structural remodeling of coronary resistance arteries: effects of age and exercise training. J Appl Physiol (1985) 2014; 117:616-23. [PMID: 25059239 PMCID: PMC4157167 DOI: 10.1152/japplphysiol.01296.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 07/21/2014] [Indexed: 12/21/2022] Open
Abstract
Age is known to induce remodeling and stiffening of large-conduit arteries; however, little is known of the effects of age on remodeling and mechanical properties of coronary resistance arteries. We employed a rat model of aging to investigate whether 1) age increases wall thickness and stiffness of coronary resistance arteries, and 2) exercise training reverses putative age-induced increases in wall thickness and stiffness of coronary resistance arteries. Young (4 mo) and old (21 mo) Fischer 344 rats remained sedentary or underwent 10 wk of treadmill exercise training. Coronary resistance arteries were isolated for determination of wall-to-lumen ratio, effective elastic modulus, and active and passive responses to changes in intraluminal pressure. Elastin and collagen content of the vascular wall were assessed histologically. Wall-to-lumen ratio increased with age, but this increase was reversed by exercise training. In contrast, age reduced stiffness, and exercise training increased stiffness in coronary resistance arteries from old rats. Myogenic responsiveness was reduced with age and restored by exercise training. Collagen-to-elastin ratio (C/E) of the wall did not change with age and was reduced with exercise training in arteries from old rats. Thus age induces hypertrophic remodeling of the vessel wall and reduces the stiffness and myogenic function of coronary resistance arteries. Exercise training reduces wall-to-lumen ratio, increases wall stiffness, and restores myogenic function in aged coronary resistance arteries. The restorative effect of exercise training on myogenic function of coronary resistance arteries may be due to both changes in vascular smooth muscle phenotype and expression of extracellular matrix proteins.
Collapse
Affiliation(s)
- Mina A Hanna
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida; Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida; Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Curtis R Taylor
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida
| | - Bei Chen
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Hae-Sun La
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida
| | - Joshua J Maraj
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida
| | - Cody R Kilar
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Bradley J Behnke
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida
| | - Michael D Delp
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida
| | - Judy M Muller-Delp
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida;
| |
Collapse
|
27
|
Tümer N, Toklu HZ, Muller-Delp JM, Oktay S, Ghosh P, Strang K, Delp MD, Scarpace PJ. The effects of aging on the functional and structural properties of the rat basilar artery. Physiol Rep 2014; 2:2/6/e12031. [PMID: 24907295 PMCID: PMC4208653 DOI: 10.14814/phy2.12031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Aging leads to progressive pathophysiological changes in blood vessels of the brain and periphery. The aim of this study was to evaluate the effects of aging on cerebral vascular function and structure. Basilar arteries were isolated from male Fischer 344 cross Brown Norway (F344xBN) rats at 3, 8, and 24 months of age. The basilar arteries were cannulated in the pressurized system (90 cm H2O). Contractile responses to KCl (30–120 mmol/L) and endothelin‐1 (10−11–10−7 mol/L) were evaluated. Responses to acetylcholine (ACh) (10−10–10−4 mol/L), diethylamine (DEA)‐NONO‐ate (10−10–10−4 mol/L), and papaverin (10−10–10−4 mol/L) were assessed to determine both endothelium‐dependent and endothelium‐independent responsiveness. Advanced aging (24 months) decreased responses of the basilar artery to both the contractile and relaxing agents; whereas, DEA‐induced dilation was significantly higher in the 8‐month‐old group compared with the younger and older groups. The arterial wall‐to‐lumen ratio was significantly increased in 24‐month‐old rats. Smooth muscle cell count was also decreased in old rats. These findings indicate that aging produces dysfunction of both the endothelium and the vascular smooth muscle in the basilar artery. Aging also alters wall structure of the basilar artery, possibly through decreases in smooth muscle cell number and concomitant hypertrophy. The purpose of this study was to determine the effects of advancing age on the structure and vasomotor responses of the basilar artery as well as the serum antioxidant capacity. Advanced aging (24 months) decreased responses of the basilar artery to both the contractile and relaxing agents, whereas, DEA‐induced dilation was significantly higher in the 8‐month‐old group compared with the younger and older rats. The arterial wall‐to‐lumen ratio was significantly increased in 24‐month‐old rats. Smooth muscle cell count was also decreased in old rats. Our findings demonstrate that aging is associated with functional impairment in endothelium‐dependent and ‐independent relaxation responses and contractility in the basilar arteries, and these diminished responses are accompanied by structural remodeling and decreased antioxidant capacity of the serum.
Collapse
Affiliation(s)
- Nihal Tümer
- Geriatric Research, Education, and Clinical Center, North Florida/South Georgia Veterans Health System, Gainesville, Florida, USA Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, USA
| | - Hale Z Toklu
- Geriatric Research, Education, and Clinical Center, North Florida/South Georgia Veterans Health System, Gainesville, Florida, USA Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, USA
| | - Judy M Muller-Delp
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Sehkar Oktay
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, USA School of Dentistry, Marmara University, Istanbul, Turkey
| | - Payal Ghosh
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Kevin Strang
- Department of Psychiatry, University of Florida, Gainesville, Florida, USA
| | - Michael D Delp
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Philip J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
28
|
Stabley JN, Prisby RD, Behnke BJ, Delp MD. Chronic skeletal unloading of the rat femur: mechanisms and functional consequences of vascular remodeling. Bone 2013; 57:355-60. [PMID: 24056176 PMCID: PMC3856860 DOI: 10.1016/j.bone.2013.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/14/2013] [Accepted: 09/11/2013] [Indexed: 11/20/2022]
Abstract
Chronic skeletal unloading diminishes hindlimb bone blood flow. The purpose of the present investigation was to determine 1) whether 7 and 14days of skeletal unloading alter femoral bone and marrow blood flow and vascular resistance during reloading, and 2) whether putative changes in bone perfusion are associated with a gross structural remodeling of the principal nutrient artery (PNA) of the femur. Six-month old male Sprague-Dawley rats were assigned to 7-d or 14-d hindlimb unloading (HU) or weight-bearing control groups. Bone perfusion was measured following 10min of standing (reloading) following the unloading treatment. Histomorphometry was used to determine PNA media wall thickness and maximal diameter. Bone blood flow, arterial pressure and PNA structural characteristics were used to calculate arterial shear stress and circumferential wall stress. During reloading, femoral perfusion was lower in the distal metaphyseal region of 7-d HU rats, and in the proximal and distal metaphyses, diaphysis and diaphyseal marrow of 14-d HU animals relative to that in control rats. Vascular resistance was also higher in all regions of the femur in 14-d HU rats during reloading relative to control animals. Intraluminal diameter of PNAs from 14-d HU rats (138±5μm) was smaller than that of control PNAs (162±6μm), and medial wall thickness was thinner in PNAs from 14-d HU (14.3±0.6μm) versus that of control (18.0±0.8μm) rats. Decreases in both shear stress and circumferential stress occurred in the PNA with HU that later returned to control levels with the reductions in PNA maximal diameter and wall thickness, respectively. The results demonstrate that chronic skeletal unloading attenuates the ability to increase blood flow and nutrient delivery to bone and marrow with immediate acute reloading due, in part, to a remodeling of the bone resistance vasculature.
Collapse
Affiliation(s)
- John N. Stabley
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, FL 32611
| | - Rhonda D. Prisby
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19716
| | - Bradley J. Behnke
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, FL 32611
| | - Michael D. Delp
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, FL 32611
| |
Collapse
|
29
|
Taylor CR, Hanna M, Behnke BJ, Stabley JN, McCullough DJ, Davis RT, Ghosh P, Papadopoulos A, Muller-Delp JM, Delp MD. Spaceflight-induced alterations in cerebral artery vasoconstrictor, mechanical, and structural properties: implications for elevated cerebral perfusion and intracranial pressure. FASEB J 2013; 27:2282-92. [PMID: 23457215 PMCID: PMC3659353 DOI: 10.1096/fj.12-222687] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 02/11/2013] [Indexed: 11/11/2022]
Abstract
Evidence indicates that cerebral blood flow is both increased and diminished in astronauts on return to Earth. Data from ground-based animal models simulating the effects of microgravity have shown that decrements in cerebral perfusion are associated with enhanced vasoconstriction and structural remodeling of cerebral arteries. Based on these results, the purpose of this study was to test the hypothesis that 13 d of spaceflight [Space Transportation System (STS)-135 shuttle mission] enhances myogenic vasoconstriction, increases medial wall thickness, and elicits no change in the mechanical properties of mouse cerebral arteries. Basilar and posterior communicating arteries (PCAs) were isolated from 9-wk-old female C57BL/6 mice for in vitro vascular and mechanical testing. Contrary to that hypothesized, myogenic vasoconstrictor responses were lower and vascular distensibility greater in arteries from spaceflight group (SF) mice (n=7) relative to ground-based control group (GC) mice (n=12). Basilar artery maximal diameter was greater in SF mice (SF: 236±9 μm and GC: 215±5 μm) with no difference in medial wall thickness (SF: 12.4±1.6 μm; GC: 12.2±1.2 μm). Stiffness of the PCA, as characterized via nanoindentation, was lower in SF mice (SF: 3.4±0.3 N/m; GC: 5.4±0.8 N/m). Collectively, spaceflight-induced reductions in myogenic vasoconstriction and stiffness and increases in maximal diameter of cerebral arteries signify that elevations in brain blood flow may occur during spaceflight. Such changes in cerebral vascular control of perfusion could contribute to increases in intracranial pressure and an associated impairment of visual acuity in astronauts during spaceflight.
Collapse
Affiliation(s)
| | - Mina Hanna
- Department of Mechanical and Aerospace Engineering
- Department of Applied Physiology and Kinesiology
| | - Bradley J. Behnke
- Department of Applied Physiology and Kinesiology
- Center for Exercise Science, and
| | - John N. Stabley
- Department of Applied Physiology and Kinesiology
- Center for Exercise Science, and
| | | | - Robert T. Davis
- Department of Applied Physiology and Kinesiology
- Center for Exercise Science, and
| | - Payal Ghosh
- Department of Applied Physiology and Kinesiology
- Center for Exercise Science, and
| | | | - Judy M. Muller-Delp
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA; and
| | - Michael D. Delp
- Department of Applied Physiology and Kinesiology
- Center for Exercise Science, and
| |
Collapse
|
30
|
Behnke BJ, Stabley JN, Ramsey MW, McCullough DJ, Dominguez JM, Lesniewski LA, Davis RT, Delp MD. Differential effects of aging and exercise training on intra‐abdominal adipose arteriolar function and blood flow regulation. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.898.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Brad J Behnke
- Applied PhysiologyUniversity of FloridaGainesvilleFL
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Davis RT, Stabley JN, Dominguez JM, Ramsey MW, McCullough DJ, Lesniewski LA, Delp MD, Behnke BJ. Differential effects of aging and exercise on intra-abdominal adipose arteriolar function and blood flow regulation. J Appl Physiol (1985) 2013; 114:808-15. [PMID: 23349454 DOI: 10.1152/japplphysiol.01358.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adipose tissue (AT), which typically comprises an increased percentage of body mass with advancing age, receives a large proportion of resting cardiac output. During exercise, an old age-associated inability to increase vascular resistance within the intra-abdominal AT may compromise the ability of the cardiovascular system to redistribute blood flow to the active musculature, contributing to the decline in exercise capacity observed in this population. We tested the hypotheses that 1) there would be an elevated perfusion of AT during exercise with old age that was associated with diminished vasoconstrictor responses of adipose-resistance arteries, and 2) chronic exercise training would mitigate the age-associated alterations in AT blood flow and vascular function. Young (6 mo; n = 40) and old (24 mo; n = 28) male Fischer 344 rats were divided into young sedentary (YSed), old sedentary (OSed), young exercise trained (YET), or old exercise trained (OET) groups, where training consisted of 10-12 wk of treadmill exercise. In vivo blood flow at rest and during exercise and in vitro α-adrenergic and myogenic vasoconstrictor responses in resistance arteries from AT were measured in all groups. In response to exercise, there was a directionally opposite change in AT blood flow in the OSed group (≈ 150% increase) and YSed (≈ 55% decrease) vs. resting values. Both α-adrenergic and myogenic vasoconstriction were diminished in OSed vs. YSed AT-resistance arteries. Exercise training resulted in a similar AT hyperemic response between age groups during exercise (YET, 9.9 ± 0.5 ml · min(-1) · 100(-1) g; OET, 8.1 ± 0.9 ml · min(-1) · 100(-1) g) and was associated with enhanced myogenic and α-adrenergic vasoconstriction of AT-resistance arteries from the OET group relative to OSed. These results indicate that there is an inability to increase vascular resistance in AT during exercise with old age, due, in part, to a diminished vasoconstriction of AT arteries. Furthermore, the results indicate that exercise training can augment vasoconstriction of AT arteries and mitigate age-related alterations in the regulation of AT blood flow during exercise.
Collapse
Affiliation(s)
- Robert T Davis
- Department of Applied Physiology and Kinesiology and Center for Exercise Science, University of Florida, Gainesville, Florida 32611, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Sindler AL, Reyes R, Chen B, Ghosh P, Gurovich AN, Kang LS, Cardounel AJ, Delp MD, Muller-Delp JM. Age and exercise training alter signaling through reactive oxygen species in the endothelium of skeletal muscle arterioles. J Appl Physiol (1985) 2013; 114:681-93. [PMID: 23288555 DOI: 10.1152/japplphysiol.00341.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exercise training ameliorates age-related impairments in endothelium-dependent vasodilation in skeletal muscle arterioles. Additionally, exercise training is associated with increased superoxide production. The purpose of this study was to determine the role of superoxide and superoxide-derived reactive oxygen species (ROS) signaling in mediating endothelium-dependent vasodilation of soleus muscle resistance arterioles from young and old, sedentary and exercise-trained rats. Young (3 mo) and old (22 mo) male rats were either exercise trained or remained sedentary for 10 wk. To determine the impact of ROS signaling on endothelium-dependent vasodilation, responses to acetylcholine were studied under control conditions and during the scavenging of superoxide and/or hydrogen peroxide. To determine the impact of NADPH oxidase-derived ROS, endothelium-dependent vasodilation was determined following NADPH oxidase inhibition. Reactivity to superoxide and hydrogen peroxide was also determined. Tempol, a scavenger of superoxide, and inhibitors of NADPH oxidase reduced endothelium-dependent vasodilation in all groups. Similarly, treatment with catalase and simultaneous treatment with tempol and catalase reduced endothelium-dependent vasodilation in all groups. Decomposition of peroxynitrite also reduced endothelium-dependent vasodilation. Aging had no effect on arteriolar protein content of SOD-1, catalase, or glutathione peroxidase-1; however, exercise training increased protein content of SOD-1 in young and old rats, catalase in young rats, and glutathione peroxidase-1 in old rats. These data indicate that ROS signaling is necessary for endothelium-dependent vasodilation in soleus muscle arterioles, and that exercise training-induced enhancement of endothelial function occurs, in part, through an increase in ROS signaling.
Collapse
Affiliation(s)
- Amy L Sindler
- Department of Physiology and Pharmacology, and the Center for Interdisciplinary Research in Cardiovascular Sciences, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Bone loss with aging and menopause may be linked to vascular endothelial dysfunction. The purpose of the study was to determine whether putative modifications in endothelium-dependent vasodilation of the principal nutrient artery (PNA) of the femur are associated with changes in trabecular bone volume (BV/TV) with altered estrogen status in young (6 mon) and old (24 mon) female Fischer-344 rats. Animals were divided into 6 groups: 1) young intact, 2) old intact, 3) young ovariectomized (OVX), 4) old OVX, 5) young OVX plus estrogen replacement (OVX+E2), and 6) old OVX+E2. PNA endothelium-dependent vasodilation was assessed in vitro using acetylcholine. Trabecular bone volume of the distal femoral metaphysis was determined by microCT. In young rats, vasodilation was diminished by OVX and restored with estrogen replacement (intact, 82±7; OVX, 61±9; OVX+E2, 90±4%), which corresponded with similar modifications in BV/TV (intact, 28.7±1.6; OVX, 16.3±0.9; OVX+E2, 25.7±1.4%). In old animals, vasodilation was unaffected by OVX but enhanced with estrogen replacement (intact, 55±8; OVX, 59±7; OVX+E2, 92±4%). Likewise, modifications in BV/TV followed the same pattern (intact, 33.1±1.6; OVX, 34.4±3.7; OVX+E2, 42.4±2.1%). Furthermore, in old animals with low endogenous estrogen (i.e., intact and old OVX), vasodilation was correlated with BV/TV (R2 = 0.630; P<0.001). These data demonstrate parallel effects of estrogen on vascular endothelial function and BV/TV, and provide for a possible coupling mechanism linking endothelium-dependent vasodilation to bone remodeling.
Collapse
Affiliation(s)
- Rhonda D. Prisby
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States of America
| | - James M. Dominguez
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida, United States of America
| | - Judy Muller-Delp
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, United States of America
| | - Matthew R. Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Michael D. Delp
- Department of Applied Physiology and Kinesiology and the Center for Exercise Science, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| |
Collapse
|
34
|
Behnke BJ, Stabley JN, McCullough DJ, Davis RT, Dominguez JM, Muller-Delp JM, Delp MD. Effects of spaceflight and ground recovery on mesenteric artery and vein constrictor properties in mice. FASEB J 2012; 27:399-409. [PMID: 23099650 DOI: 10.1096/fj.12-218503] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Following exposure to microgravity, there is a reduced ability of astronauts to augment peripheral vascular resistance, often resulting in orthostatic hypotension. The purpose of this study was to test the hypothesis that mesenteric arteries and veins will exhibit diminished vasoconstrictor responses after spaceflight. Mesenteric arteries and veins from female mice flown on the Space Transportation System (STS)-131 (n=11), STS-133 (n=6), and STS-135 (n=3) shuttle missions and respective ground-based control mice (n=30) were isolated for in vitro experimentation. Vasoconstrictor responses were evoked in arteries via norepinephrine (NE), potassium chloride (KCl), and caffeine, and in veins through NE across a range of intraluminal pressures (2-12 cmH(2)O). Vasoconstriction to NE was also determined in mesenteric arteries at 1, 5, and 7 d postlanding. In arteries, maximal constriction to NE, KCl, and caffeine were reduced immediately following spaceflight and 1 d postflight. Spaceflight also reduced arterial ryanodine receptor-3 mRNA levels. In mesenteric veins, there was diminished constriction to NE after flight. The results indicate that the impaired vasoconstriction following spaceflight occurs through the ryanodine receptor-mediated intracellular Ca(2+) release mechanism. Such vascular changes in astronauts could compromise the maintenance of arterial pressure during orthostatic stress.
Collapse
Affiliation(s)
- Bradley J Behnke
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611-8205, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Behnke BJ, Ramsey MW, Stabley JN, Dominguez JM, Davis RT, McCullough DJ, Muller-Delp JM, Delp MD. Effects of aging and exercise training on skeletal muscle blood flow and resistance artery morphology. J Appl Physiol (1985) 2012; 113:1699-708. [PMID: 23042906 DOI: 10.1152/japplphysiol.01025.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
With old age, blood flow to the high-oxidative red skeletal muscle is reduced and blood flow to the low-oxidative white muscle is elevated during exercise. Changes in the number of feed arteries perforating the muscle are thought to contribute to this altered hyperemic response during exercise. We tested the hypothesis that exercise training would ameliorate age-related differences in blood flow during exercise and feed artery structure in skeletal muscle. Young (6-7 mo old, n = 36) and old (24 mo old, n = 25) male Fischer 344 rats were divided into young sedentary (Sed), old Sed, young exercise-trained (ET), and old ET groups, where training consisted of 10-12 wk of treadmill exercise. In Sed and ET rats, blood flow to the red and white portions of the gastrocnemius muscle (Gast(Red) and Gast(White)) and the number and luminal cross-sectional area (CSA) of all feed arteries perforating the muscle were measured at rest and during exercise. In the old ET group, blood flow was greater to Gast(Red) (264 ± 13 and 195 ± 9 ml · min(-1) · 100 g(-1) in old ET and old Sed, respectively) and lower to Gast(White) (78 ± 5 and 120 ± 6 ml · min(-1) · 100 g(-1) in old ET and old Sed, respectively) than in the old Sed group. There was no difference in the number of feed arteries between the old ET and old Sed group, although the CSA of feed arteries from old ET rats was larger. In young ET rats, there was an increase in the number of feed arteries perforating the muscle. Exercise training mitigated old age-associated differences in blood flow during exercise within gastrocnemius muscle. However, training-induced adaptations in resistance artery morphology differed between young (increase in feed artery number) and old (increase in artery CSA) animals. The altered blood flow pattern induced by exercise training with old age would improve the local matching of O(2) delivery to consumption within the skeletal muscle.
Collapse
Affiliation(s)
- Bradley J Behnke
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida 32611, USA.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Stabley JN, Dominguez JM, Dominguez CE, Mora Solis FR, Ahlgren J, Behnke BJ, Muller-Delp JM, Delp MD. Spaceflight reduces vasoconstrictor responsiveness of skeletal muscle resistance arteries in mice. J Appl Physiol (1985) 2012; 113:1439-45. [PMID: 22984246 DOI: 10.1152/japplphysiol.00772.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cardiovascular adaptations to microgravity undermine the physiological capacity to respond to orthostatic challenges upon return to terrestrial gravity. The purpose of the present study was to investigate the influence of spaceflight on vasoconstrictor and myogenic contractile properties of mouse gastrocnemius muscle resistance arteries. We hypothesized that vasoconstrictor responses acting through adrenergic receptors [norepinephrine (NE)], voltage-gated Ca(2+) channels (KCl), and stretch-activated (myogenic) mechanisms would be diminished following spaceflight. Feed arteries were isolated from gastrocnemius muscles, cannulated on glass micropipettes, and physiologically pressurized for in vitro experimentation. Vasoconstrictor responses to intraluminal pressure changes (0-140 cmH(2)O), KCl (10-100 mM), and NE (10(-9)-10(-4) M) were measured in spaceflown (SF; n = 11) and ground control (GC; n = 11) female C57BL/6 mice. Spaceflight reduced vasoconstrictor responses to KCl and NE; myogenic vasoconstriction was unaffected. The diminished vasoconstrictor responses were associated with lower ryanodine receptor-2 (RyR-2) and ryanodine receptor-3 (RyR-3) mRNA expression, with no difference in sarcoplasmic/endoplasmic Ca(2+) ATPase 2 mRNA expression. Vessel wall thickness and maximal intraluminal diameter were unaffected by spaceflight. The data indicate a deficit in intracellular calcium release via RyR-2 and RyR-3 in smooth muscle cells as the mechanism of reduced contractile activity in skeletal muscle after spaceflight. Furthermore, the results suggest that impaired end-organ vasoconstrictor responsiveness of skeletal muscle resistance arteries contributes to lower peripheral vascular resistance and less tolerance of orthostatic stress in humans after spaceflight.
Collapse
Affiliation(s)
- John N Stabley
- Department of Applied Physiology and Kinesiology and Center for Exercise Science, University of Florida, Gainesville, Florida 32611, USA
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Park Y, Prisby RD, Behnke BJ, Dominguez JM, Lesniewski LA, Donato AJ, Muller-Delp J, Delp MD. Effects of aging, TNF-α, and exercise training on angiotensin II-induced vasoconstriction of rat skeletal muscle arterioles. J Appl Physiol (1985) 2012; 113:1091-100. [PMID: 22923503 DOI: 10.1152/japplphysiol.00292.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle vascular resistance during physical exertion is higher with old age. The purpose of this study was to determine whether 1) aging enhances angiotensin II (ANG II)-induced vasoconstriction; 2) the proinflammatory cytokine tumor necrosis factor (TNF)-α contributes to alterations in ANG II-mediated vasoconstriction with aging; 3) exercise training attenuates putative age-associated increases in ANG II-mediated vasoconstriction; and 4) the mechanism(s) through which aging and exercise training alters ANG II-induced vasoconstriction in skeletal muscle arterioles. Male Fischer 344 rats were assigned to four groups: young sedentary (4 mo), old sedentary (24 mo), young trained, and old trained. In a separate group of young sedentary and old sedentary animals, a TNF type 1 receptor inhibitor was administered subcutaneously for 10 wk. First-order arterioles were isolated from soleus and gastrocnemius muscles for in vitro experimentation. Old age augmented ANG II-induced vasoconstriction in both soleus (young: 27 ± 3%; old: 38 ± 4%) and gastrocnemius (young: 42 ± 6%; old: 64 ± 9%) muscle arterioles; this augmented vasoconstriction was abolished with the removal of the endothelium, N(G)-nitro-l-arginine methyl ester, and chronic inhibition of TNF-α. In addition, exercise training ameliorated the age-induced increase in ANG II vasoconstriction. These findings demonstrate that old age enhances and exercise training diminishes ANG II-induced vasoconstrictor responses in skeletal muscle arterioles through an endothelium-dependent nitric oxide synthase signaling pathway. In addition, the enhancement of ANG II vasoconstriction with old age appears to be related to a proinflammatory state.
Collapse
Affiliation(s)
- Yoonjung Park
- Department of Health, Exercise and Sport Sciences, Texas Tech University, Lubbock, TX, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Hanna M, Stabley JN, McCullough DJ, Dominguez JM, Muller-Delp JM, Behnke BJ, Taylor CR, Delp MD. Effects of spaceflight on vasoconstrictor and mechanical properties of mouse cerebral arteries. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.lb660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mina Hanna
- Mechanical & Aerospace EngineeringUniversity of FloridaGainesvilleFL
| | - John N Stabley
- Applied Physiology & KinesiologyUniversity of FloridaGainesvilleFL
| | | | | | | | - Bradley J Behnke
- Applied Physiology & KinesiologyUniversity of FloridaGainesvilleFL
| | - Curtis R Taylor
- Mechanical & Aerospace EngineeringUniversity of FloridaGainesvilleFL
| | - Michael D Delp
- Applied Physiology & KinesiologyUniversity of FloridaGainesvilleFL
| |
Collapse
|
39
|
Stabley JN, Davis RT, Moningka NC, Behnke BJ, Delp MD. Endurance exercise training enhances regional femoral and tibial bone blood flow during exercise. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1142.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John N. Stabley
- Applied Physiology and KinesiologyUniversity of FloridaGainesvilleFL
| | - Robert T. Davis
- Applied Physiology and KinesiologyUniversity of FloridaGainesvilleFL
| | | | - Bradley J. Behnke
- Applied Physiology and KinesiologyUniversity of FloridaGainesvilleFL
| | - Michael D. Delp
- Applied Physiology and KinesiologyUniversity of FloridaGainesvilleFL
| |
Collapse
|
40
|
Gurovich AN, Ghosh P, Sapp GH, Chen B, Delp MD, Muller-Delp JM. Aerobic exercise affects body weight differently in young and old rats. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.lb731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alvaro N. Gurovich
- Applied Medicine and RehabilitationIndiana State UniversityTerre HauteIN
- Physiology and Functional GenomicsUniversity of FloridaGainesvillleFL
| | - Payal Ghosh
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillleFL
| | - Glenn H. Sapp
- Physiology and Functional GenomicsUniversity of FloridaGainesvillleFL
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillleFL
| | - Bei Chen
- Physiology and Functional GenomicsUniversity of FloridaGainesvillleFL
| | - Michael D. Delp
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillleFL
| | | |
Collapse
|
41
|
Behnke BJ, Armstrong RB, Delp MD. Adrenergic control of vascular resistance varies in muscles composed of different fiber types: influence of the vascular endothelium. Am J Physiol Regul Integr Comp Physiol 2011; 301:R783-90. [PMID: 21677269 DOI: 10.1152/ajpregu.00205.2011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The influence of the sympathetic nervous system (SNS) upon vascular resistance is more profound in muscles comprised predominately of low-oxidative type IIB vs. high-oxidative type I fiber types. However, within muscles containing high-oxidative type IIA and IIX fibers, the role of the SNS on vasomotor tone is not well established. The purpose of this study was to examine the influence of sympathetic neural vasoconstrictor tone in muscles composed of different fiber types. In adult male rats, blood flow to the red and white portions of the gastrocnemius (Gast(Red) and Gast(White), respectively) and the soleus muscle was measured pre- and postdenervation. Resistance arterioles from these muscles were removed, and dose responses to α₁-phenylephrine or α₂-clonidine adrenoreceptor agonists were determined with and without the vascular endothelium. Denervation resulted in a 2.7-fold increase in blood flow to the soleus and Gast(Red) and an 8.7-fold increase in flow to the Gast(White). In isolated arterioles, α₂-mediated vasoconstriction was greatest in Gast(White) (∼50%) and less in Gast(Red) (∼31%) and soleus (∼17%); differences among arterioles were abolished with the removal of the endothelium. There was greater sensitivity to α(1)-mediated vasoconstriction in the Gast(White) and Gast(Red) vs. the soleus, which was independent of whether the endothelium was present. These data indicate that 1) control of vascular resistance by the SNS in high-oxidative, fast-twitch muscle is intermediate to that of low-oxidative, fast-twitch and high-oxidative, slow-twitch muscles; and 2) the ability of the SNS to control blood flow to low-oxidative type IIB muscle appears to be mediated through postsynaptic α₁- and α₂-adrenoreceptors on the vascular smooth muscle.
Collapse
Affiliation(s)
- Bradley J Behnke
- Department of Applied Physiology and Kinesiology and Center for Exercise Science, University of Florida, Gainesville, Florida, USA.
| | | | | |
Collapse
|
42
|
Stabley JN, Dominguez CE, Mora F, Ahlgren J, Dominguez JM, Behnke BJ, Muller-Delp JM, Delp MD. Fifteen Days of Space Flight Reduces Vasoconstriction in Gastrocnemius Muscle Feed Arteries. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000389525.21390.cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
43
|
McCullough DJ, Davis RT, Delp MD, Behnke BJ. Effects Of Aging On Vasoconstrictor Dynamics In Soleus Resistance Arteries. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000386028.27551.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
44
|
Behnke BJ, Dominguez JM, Park Y, Delp MD. Angiotensin II‐Induced Vasoconstriction in Skeletal Muscle: Effects of Aging and TNF‐α. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.775.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Yoonjung Park
- Internal Medicine and the Dalton Cardiovascular Research CenterUniversity of MissouriColumbiaMO
| | - Michael D Delp
- Applied Physiology & Kinesiology and the Center for Exercise Science
| |
Collapse
|
45
|
Dominguez JM, Prisby RD, Muller-Delp JM, Allen MR, Delp MD. Increased nitric oxide-mediated vasodilation of bone resistance arteries is associated with increased trabecular bone volume after endurance training in rats. Bone 2010; 46:813-9. [PMID: 19892040 PMCID: PMC2823927 DOI: 10.1016/j.bone.2009.10.029] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 12/13/2022]
Abstract
Old age-associated osteoporosis is related to diminished bone blood flow and impaired nitric oxide (NO)-mediated vasodilation of the bone vasculature. Endurance exercise training restores the age-associated reduction of vasodilation in numerous vascular beds, as well as improving bone properties. The purpose of this study was to determine whether functional improvements in the bone vasculature are associated with increased bone properties after an endurance training intervention. Young adult (4-6 months) and old (24-26 months) male Fischer-344 rats remained sedentary or were trained (15 m/min walking, 15 degrees incline, 5 days/week, 10-12 weeks). Endothelium-dependent vasodilation of the femoral principal nutrient artery (PNA) was assessed in vitro using acetylcholine (ACh) and inhibitors of NO synthase (NOS) and cyclooxygenase (COX). PNA endothelium-dependent vasodilation was greater after training by 16% in young and by 24% in old animals. The NOS-mediated contribution to endothelium-dependent vasodilation was enhanced by 77% after training in old rats. Distal femur trabecular bone volume (BV/TV, %) was lower with old age in sedentary animals (young: 27+/-2%, old: 23+/-1%; P<0.05). Exercise-induced elevations in bone and marrow blood flow and the NOS signaling pathway were associated with greater BV/TV (young trained: 34+/-2%, old trained: 26+/-1%; P<0.05) relative to sedentary groups. These data demonstrate that training-induced increases in bone properties are associated with enhanced endothelium-dependent vasodilation through a NOS signaling pathway in the bone vasculature.
Collapse
Affiliation(s)
- James M. Dominguez
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, FL 32611
| | - Rhonda D. Prisby
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX 76019
| | - Judy M. Muller-Delp
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32611
| | - Matthew R. Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael D. Delp
- Department of Applied Physiology and Kinesiology, and the Center for Exercise Science, University of Florida, Gainesville, FL 32611
| |
Collapse
|
46
|
Abstract
Aging is associated with an altered ability to match oxygen delivery (QO2) to consumption ((.)VO2) in skeletal muscle and differences in the temporal profile of vasodilation may provide a mechanistic basis for the QO2-to-(.)VO2 mismatching during the rest-to-exercise transition. Therefore, we tested the hypothesis that the speed of vasodilation will be blunted in skeletal muscle first-order arterioles from old vs. young rats. Arterioles from the soleus and the red portion of the gastrocnemius (Gast(Red)) muscles were isolated from young (Y, 6 mo; n = 9) and old (O, 24 mo; n = 9) Fischer 344 rats and studied in vitro. Vessels were exposed to acetylcholine (ACh; 10(-6) M), sodium nitroprusside (SNP; 10(-4) M), and increased intraluminal flow, and the subsequent vasodilation was recorded at 30 frames/s. The data were fit to a monoexponential model and the dynamics of vasodilation [i.e., time delay, time constant (tau), and rate of change (delta/tau)] were calculated. With old age, the rate of vasodilation was significantly blunted in resistance vessels from the soleus to ACh (Y, 27.9 +/- 3.6; O, 8.8 +/- 2.6 microm/s) and flow (Y, 12.8 +/- 2.1; O, 3.1 +/- 0.9 microm/s). In the Gast(Red) the old age-associated impairment of endothelium-dependent vasodilator dynamics was even greater than that of the soleus. With SNP neither the magnitude nor time constant of vasodilation was affected by age in either muscle. The results indicate that aging impairs the dynamics of vasodilation in resistance vessels from the soleus and Gast(Red) muscles mediated, in part, through the endothelium. Thus the old age-associated slower rate and magnitude of vasodilation could inhibit the delivery of O2 during the critical transition from rest to exercise in moderate to highly oxidative skeletal muscle.
Collapse
Affiliation(s)
- Bradley J Behnke
- Dept. of Applied Physiology and Kinesiology, Center for Exercise Science, 124 FLG, PO Box 118205, Univ. of Florida, Gainesville, FL 32611, USA.
| | | |
Collapse
|
47
|
Sindler AL, Delp MD, Reyes R, Wu G, Muller-Delp JM. Effects of ageing and exercise training on eNOS uncoupling in skeletal muscle resistance arterioles. J Physiol 2009; 587:3885-97. [PMID: 19528246 PMCID: PMC2746616 DOI: 10.1113/jphysiol.2009.172221] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 06/14/2009] [Indexed: 01/03/2023] Open
Abstract
Reduced availability of tetrahydrobiopterin (BH(4)) contributes to the age-related decline of nitric oxide (NO)-mediated vasodilatation of soleus muscle arterioles. Depending on availability of substrate and/or necessary co-factors, endothelial nitric oxide synthase (eNOS) can generate NO and/or superoxide (O(2)(-)). We evaluated the effects of age and chronic exercise on flow-induced vasodilatation and levels of NO and O(2)(-) in soleus muscle arterioles. Young (3 months) and old (22 months) male rats were exercise trained or remained sedentary (SED) for 10 weeks. Flow-stimulated NO and O(2)(-), as well as BH(4) and l-arginine content, were determined in soleus muscle arterioles. Flow-induced vasodilatation was assessed under control conditions and during the blockade of O(2)(-) and/or hydrogen peroxide. Exercise training enhanced flow-induced vasodilatation in arterioles from young and old rats. Old age reduced, and exercise training restored, BH(4) content and flow-stimulated NO availability. Flow-stimulated, eNOS-derived O(2)(-) levels were higher in arterioles from old SED compared to those from young SED rats. Exercise training increased flow-stimulated eNOS-derived O(2)(-) levels in arterioles from young but not old rats. O(2)(-) scavenging with Tempol reduced flow-induced vasodilatation from all groups except young SED rats. Addition of catalase to Tempol-treated arterioles eliminated flow-induced vasodilatation in arterioles from all groups. Catalase reduced flow-induced vasodilatation from all groups. In Tempol-treated arterioles, flow-induced vasodilatation was restored by deferoxamine, an iron chelator. These data indicate that uncoupling of eNOS contributes to the age-related decline in flow-induced vasodilatation; however, reactive oxygen species are required for flow-induced vasodilatation in soleus muscle arterioles from young and old rats.
Collapse
Affiliation(s)
- Amy L Sindler
- Department of Physiology and Pharmacology, West Virginia University, School of Medicine, Morgantown, WV 26506, USA
| | | | | | | | | |
Collapse
|
48
|
Behnke BJ, Delp MD. Aging Blunts The Dynamics Of Vasodilation In Isolated Resistance Vessels From The Red Gastrocnemius. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000353602.97135.78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
49
|
Sindler AL, Delp MD, Reyes RA, Wu G, Muller‐Delp JM. Effect of aging and exercise training on eNOS uncoupling and O2‐ signaling in skeletal muscle arterioles. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.608.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Rafael A Reyes
- Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Guoyao Wu
- Texas A&M UniversityCollege StationTX
| | | |
Collapse
|
50
|
Behnke BJ, Armstrong RB, Delp MD. Adrenergic Regulation of Vasomotor Responses in Skeletal Muscle Composed of Different Fiber Types. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.787.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Brad J Behnke
- Applied Physiology & Kinesiology; Center for Exercise ScienceUniversity of FloridaGainesvilleFL
| | | | - Michael D Delp
- Applied Physiology & Kinesiology; Center for Exercise ScienceUniversity of FloridaGainesvilleFL
| |
Collapse
|