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Burtscher J, Strasser B, Burtscher M. A mito-centric view on muscle aging and function. Front Public Health 2024; 11:1330131. [PMID: 38269379 PMCID: PMC10806989 DOI: 10.3389/fpubh.2023.1330131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/19/2023] [Indexed: 01/26/2024] Open
Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Barbara Strasser
- Ludwig Boltzmann Institute for Rehabilitation Research, Vienna, Austria
- Faculty of Medicine, Sigmund Freud Private University, Vienna, Austria
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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2
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Castillejos-López M, Romero Y, Varela-Ordoñez A, Flores-Soto E, Romero-Martinez BS, Velázquez-Cruz R, Vázquez-Pérez JA, Ruiz V, Gomez-Verjan JC, Rivero-Segura NA, Camarena Á, Torres-Soria AK, Gonzalez-Avila G, Sommer B, Solís-Chagoyán H, Jaimez R, Torres-Espíndola LM, Aquino-Gálvez A. Hypoxia Induces Alterations in the Circadian Rhythm in Patients with Chronic Respiratory Diseases. Cells 2023; 12:2724. [PMID: 38067152 PMCID: PMC10706372 DOI: 10.3390/cells12232724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/08/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
The function of the circadian cycle is to determine the natural 24 h biological rhythm, which includes physiological, metabolic, and hormonal changes that occur daily in the body. This cycle is controlled by an internal biological clock that is present in the body's tissues and helps regulate various processes such as sleeping, eating, and others. Interestingly, animal models have provided enough evidence to assume that the alteration in the circadian system leads to the appearance of numerous diseases. Alterations in breathing patterns in lung diseases can modify oxygenation and the circadian cycles; however, the response mechanisms to hypoxia and their relationship with the clock genes are not fully understood. Hypoxia is a condition in which the lack of adequate oxygenation promotes adaptation mechanisms and is related to several genes that regulate the circadian cycles, the latter because hypoxia alters the production of melatonin and brain physiology. Additionally, the lack of oxygen alters the expression of clock genes, leading to an alteration in the regularity and precision of the circadian cycle. In this sense, hypoxia is a hallmark of a wide variety of lung diseases. In the present work, we intended to review the functional repercussions of hypoxia in the presence of asthma, chronic obstructive sleep apnea, lung cancer, idiopathic pulmonary fibrosis, obstructive sleep apnea, influenza, and COVID-19 and its repercussions on the circadian cycles.
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Affiliation(s)
- Manuel Castillejos-López
- Departamento de Epidemiología e Infectología Hospitalaria, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
| | - Yair Romero
- Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico;
| | - Angelica Varela-Ordoñez
- Red MEDICI, Carrera de Médico Cirujano, Facultad de Estudios Superiores de Iztacala Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (A.V.-O.); (A.K.T.-S.)
| | - Edgar Flores-Soto
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.F.-S.); (B.S.R.-M.); (R.J.)
| | - Bianca S. Romero-Martinez
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.F.-S.); (B.S.R.-M.); (R.J.)
| | - Rafael Velázquez-Cruz
- Laboratorio de Genómica del Metabolismo Óseo, Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City 14610, Mexico;
| | - Joel Armando Vázquez-Pérez
- Laboratorio de Biología Molecular de Enfermedades Emergentes y EPOC, Instituto Nacional de Enferdades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
| | - Víctor Ruiz
- Laboratorio de Biología Molecular, Departamento de Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional (INP), Mexico City 11340, Mexico
| | - Juan C. Gomez-Verjan
- Dirección de Investigación, Instituto Nacional de Geriatría (INGER), Mexico City 10200, Mexico; (J.C.G.-V.); (N.A.R.-S.)
| | - Nadia A. Rivero-Segura
- Dirección de Investigación, Instituto Nacional de Geriatría (INGER), Mexico City 10200, Mexico; (J.C.G.-V.); (N.A.R.-S.)
| | - Ángel Camarena
- Laboratorio de Inmunobiología y Genética, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
| | - Ana Karen Torres-Soria
- Red MEDICI, Carrera de Médico Cirujano, Facultad de Estudios Superiores de Iztacala Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (A.V.-O.); (A.K.T.-S.)
| | - Georgina Gonzalez-Avila
- Laboratorio de Oncología Biomédica, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
| | - Bettina Sommer
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
| | - Héctor Solís-Chagoyán
- Laboratorio de Neurobiología Cognitiva, Centro de Investigación en Ciencias Cognitivas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico;
| | - Ruth Jaimez
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.F.-S.); (B.S.R.-M.); (R.J.)
| | | | - Arnoldo Aquino-Gálvez
- Laboratorio de Biología Molecular, Departamento de Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), Mexico City 14080, Mexico;
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico
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3
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Rybnikova EA, Nalivaeva NN, Zenko MY, Baranova KA. Intermittent Hypoxic Training as an Effective Tool for Increasing the Adaptive Potential, Endurance and Working Capacity of the Brain. Front Neurosci 2022; 16:941740. [PMID: 35801184 PMCID: PMC9254677 DOI: 10.3389/fnins.2022.941740] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
This review is devoted to the phenomenon of intermittent hypoxic training and is aimed at drawing the attention of researchers to the necessity of studying the mechanisms mediating the positive, particularly neuroprotective, effects of hypoxic training at the molecular level. The review briefly describes the historical aspects of studying the beneficial effects of mild hypoxia, as well as the use of hypoxic training in medicine and sports. The physiological mechanisms of hypoxic adaptation, models of hypoxic training and their effectiveness are summarized, giving examples of their beneficial effects in various organs including the brain. The review emphasizes a high, far from being realized at present, potential of hypoxic training in preventive and clinical medicine especially in the area of neurodegeneration and age-related cognitive decline.
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Affiliation(s)
- Elena A. Rybnikova
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
- *Correspondence: Elena A. Rybnikova,
| | - Natalia N. Nalivaeva
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of Russian Academy of Sciences, St. Petersburg, Russia
| | - Mikhail Y. Zenko
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
| | - Ksenia A. Baranova
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
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4
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Ortiz-Prado E, Espinosa PS, Borrero A, Cordovez SP, Vasconez JE, Barreto-Grimales A, Coral-Almeida M, Henriquez-Trujillo AR, Simbaña-Rivera K, Gomez-Barreno L, Viscor G, Roderick P. Stroke-Related Mortality at Different Altitudes: A 17-Year Nationwide Population-Based Analysis From Ecuador. Front Physiol 2021; 12:733928. [PMID: 34675818 PMCID: PMC8525493 DOI: 10.3389/fphys.2021.733928] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/08/2021] [Indexed: 12/23/2022] Open
Abstract
Introduction: Worldwide, more than 5.7% of the population reside above 1,500 m of elevation. It has been hypothesized that acute short-term hypoxia exposure could increase the risk of developing a stroke. Studies assessing the effect of altitude on stroke have provided conflicting results, some analyses suggest that long-term chronic exposure could be associated with reduced mortality and lower stroke incidence rates. Methods: An ecological analysis of all stroke hospital admissions, mortality rates, and disability-adjusted life years in Ecuador was performed from 2001 to 2017. The cases and population at risk were categorized in low (<1,500 m), moderate (1,500–2,500 m), high (2,500–3,500 m), and very high altitude (3,500–5,500 m) according to the place of residence. The derived crude and direct standardized age-sex adjusted mortality and hospital admission rates were calculated. Results: A total of 38,201 deaths and 75,893 stroke-related hospital admissions were reported. High altitude populations (HAP) had lower stroke mortality in men [OR: 0.91 (0.88–0.95)] and women [OR: 0.83 (0.79–0.86)]. In addition, HAP had a significant lower risk of getting admitted to the hospital when compared with the low altitude group in men [OR: 0.55 (CI 95% 0.54–0.56)] and women [OR: 0.65 (CI 95% 0.64–0.66)]. Conclusion: This is the first epidemiological study that aims to elucidate the association between stroke and altitude using four different elevation ranges. Our findings suggest that living at higher elevations offers a reduction or the risk of dying due to stroke as well as a reduction in the probability of being admitted to the hospital. Nevertheless, this protective factor has a stronger effect between 2,000 and 3,500 m.
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Affiliation(s)
- Esteban Ortiz-Prado
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador.,Departamento de Biología Celular, Fisiología e Inmunología, Universitat de Barcelona, Barcelona, Spain
| | - Patricio S Espinosa
- Neurology, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, United States
| | - Alfredo Borrero
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador
| | - Simone P Cordovez
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador
| | - Jorge E Vasconez
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador
| | | | - Marco Coral-Almeida
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador
| | | | | | - Lenin Gomez-Barreno
- One Health Research Group, Faculty of Medicine, Universidad de Las Américas, Quito, Ecuador
| | - Gines Viscor
- Departamento de Biología Celular, Fisiología e Inmunología, Universitat de Barcelona, Barcelona, Spain
| | - Paul Roderick
- Faculty of Medicine, School of Primary Care, Population Sciences and Medical Education, University of Southampton, Southampton, United Kingdom
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5
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A Rationale for Hypoxic and Chemical Conditioning in Huntington's Disease. Int J Mol Sci 2021; 22:ijms22020582. [PMID: 33430140 PMCID: PMC7826574 DOI: 10.3390/ijms22020582] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
Neurodegenerative diseases are characterized by adverse cellular environments and pathological alterations causing neurodegeneration in distinct brain regions. This development is triggered or facilitated by conditions such as hypoxia, ischemia or inflammation and is associated with disruptions of fundamental cellular functions, including metabolic and ion homeostasis. Targeting intracellular downstream consequences to specifically reverse these pathological changes proved difficult to translate to clinical settings. Here, we discuss the potential of more holistic approaches with the purpose to re-establish a healthy cellular environment and to promote cellular resilience. We review the involvement of important molecular pathways (e.g., the sphingosine, δ-opioid receptor or N-Methyl-D-aspartate (NMDA) receptor pathways) in neuroprotective hypoxic conditioning effects and how these pathways can be targeted for chemical conditioning. Despite the present scarcity of knowledge on the efficacy of such approaches in neurodegeneration, the specific characteristics of Huntington’s disease may make it particularly amenable for such conditioning techniques. Not only do classical features of neurodegenerative diseases like mitochondrial dysfunction, oxidative stress and inflammation support this assumption, but also specific Huntington’s disease characteristics: a relatively young age of neurodegeneration, molecular overlap of related pathologies with hypoxic adaptations and sensitivity to brain hypoxia. The aim of this review is to discuss several molecular pathways in relation to hypoxic adaptations that have potential as drug targets in neurodegenerative diseases. We will extract the relevance for Huntington’s disease from this knowledge base.
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6
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Combined stimuli of cold, hypoxia, and dehydration status on body temperature in rats: a pilot study with practical implications for humans. BMC Res Notes 2020; 13:530. [PMID: 33176867 PMCID: PMC7661168 DOI: 10.1186/s13104-020-05375-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/05/2020] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVE As human thermoregulatory responses to maintain core body temperature (Tcore) under multiple stressors such as cold, hypoxia, and dehydration (e.g., exposure to high-altitude) are varied, the combined effects of cold, hypoxia, and dehydration status on Tcore in rats were investigated. The following environmental conditions were constructed: (1) thermoneutral (24 °C) or cold (10 °C), (2) normoxia (21% O2) or hypoxia (12% O2), and (3) euhydration or dehydration (48 h water deprivation), resulted in eight environmental conditions [2 ambient temperatures (Ta) × 2 oxygen levels × 2 hydration statuses)]. Each condition lasted for 24 h. RESULTS Normoxic conditions irrespective of hypoxia or dehydration did not strongly decrease the area under the curve (AUC) in Tcore during the 24 period, whereas, hypoxic conditions caused greater decreases in the AUC in Tcore, which was accentuated with cold and dehydration (Ta × O2 × hydration, P = 0.040 by three-way ANOVA). In contrast, multiple stressors (Ta × O2 × hydration or Ta × O2 or O2 × hydration or Ta × hydration) did not affect locomotor activity counts (all P > 0.05), but a significant simple main effect for O2 and Ta was observed (P < 0.001). Heat loss index was not affected by all environmental conditions (all P > 0.05). In conclusion, decreases in Tcore were most affected by multiple environmental stressors such as cold, hypoxia, and dehydration.
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7
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Deng Y, Wang ZV, Gordillo R, An Y, Zhang C, Liang Q, Yoshino J, Cautivo KM, De Brabander J, Elmquist JK, Horton JD, Hill JA, Klein S, Scherer PE. An adipo-biliary-uridine axis that regulates energy homeostasis. Science 2017; 355:355/6330/eaaf5375. [PMID: 28302796 DOI: 10.1126/science.aaf5375] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 01/17/2017] [Indexed: 12/12/2022]
Abstract
Uridine, a pyrimidine nucleoside present at high levels in the plasma of rodents and humans, is critical for RNA synthesis, glycogen deposition, and many other essential cellular processes. It also contributes to systemic metabolism, but the underlying mechanisms remain unclear. We found that plasma uridine levels are regulated by fasting and refeeding in mice, rats, and humans. Fasting increases plasma uridine levels, and this increase relies largely on adipocytes. In contrast, refeeding reduces plasma uridine levels through biliary clearance. Elevation of plasma uridine is required for the drop in body temperature that occurs during fasting. Further, feeding-induced clearance of plasma uridine improves glucose metabolism. We also present findings that implicate leptin signaling in uridine homeostasis and consequent metabolic control and thermoregulation. Our results indicate that plasma uridine governs energy homeostasis and thermoregulation in a mechanism involving adipocyte-dependent uridine biosynthesis and leptin signaling.
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Affiliation(s)
- Yingfeng Deng
- Touchstone Diabetes Center, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Zhao V Wang
- Division of Cardiology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yu An
- Touchstone Diabetes Center, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chen Zhang
- Touchstone Diabetes Center, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Qiren Liang
- Department of Biochemistry and Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jun Yoshino
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, USA
| | - Kelly M Cautivo
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jef De Brabander
- Department of Biochemistry and Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jay D Horton
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Joseph A Hill
- Division of Cardiology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Samuel Klein
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA.
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Chiu SC, Lin YJ, Huang SY, Lien CF, Chen SP, Pang CY, Lin JH, Yang KT. The Role of Intermittent Hypoxia on the Proliferative Inhibition of Rat Cerebellar Astrocytes. PLoS One 2015; 10:e0132263. [PMID: 26172116 PMCID: PMC4501806 DOI: 10.1371/journal.pone.0132263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Accepted: 06/11/2015] [Indexed: 01/28/2023] Open
Abstract
Sleep apnea syndrome, characterized by intermittent hypoxia (IH), is linked with increased oxidative stress. This study investigates the mechanisms underlying IH and the effects of IH-induced oxidative stress on cerebellar astrocytes. Rat primary cerebellar astrocytes were kept in an incubator with an oscillating O2 concentration between 20% and 5% every 30 min for 1–4 days. Although the cell loss increased with the duration, the IH incubation didn’t induce apoptosis or necrosis, but rather a G0/G1 cell cycle arrest of cerebellar astrocytes was noted. ROS accumulation was associated with cell loss during IH. PARP activation, resulting in p21 activation and cyclin D1 degradation was associated with cell cycle G0/G1 arrest of IH-treated cerebellar astrocytes. Our results suggest that IH induces cell loss by enhancing oxidative stress, PARP activation and cell cycle G0/G1 arrest in rat primary cerebellar astrocytes.
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Affiliation(s)
- Sheng-Chun Chiu
- Department of Research, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
| | - Yu-Jou Lin
- Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Sung-Ying Huang
- Department of Ophthalmology, Mackay Memorial Hospital, Hsinchu, Taiwan
| | - Chih-Feng Lien
- Institute of Medical Sciences, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Shee-Ping Chen
- Tzu Chi Stem Cells Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Cheng-Yoong Pang
- Institute of Medical Sciences, School of Medicine, Tzu Chi University, Hualien, Taiwan
- Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Jian-Hong Lin
- PhD program in Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan
| | - Kun-Ta Yang
- Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien, Taiwan
- Department of Physiology, School of Medicine, Tzu Chi University, Hualien, Taiwan
- * E-mail:
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9
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Branco LGS, Bicego KC, Carnio EC, Pittman QJ. Gaseous neurotransmitters and their role in anapyrexia. Front Biosci (Elite Ed) 2010; 2:948-60. [PMID: 20515766 DOI: 10.2741/e154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mammals keep their body temperature (Tb) relatively constant even under a wide range of ambient temperature variation. However, in some particular situations it may be beneficial to increase or to decrease Tb. For instance, under hypoxic conditions, a regulated drop in Tb (anapyrexia) takes place which has been reported to be crucial for survival in a number of different species. This review highlights major advances in the research about nitric oxide (NO) and carbon monoxide (CO- where data are relatively less abundant), before focusing on the role played by these gaseous neuromediators in thermoregulation, under the conditions of euthermia and anapyrexia. Available data are consistent with the notion that both NO and CO, acting on the CNS, participate in thermoregulation, with NO decreasing Tb and CO increasing it. However further studies are required before definitive conclusions can be made as to their physiological mechanisms of action.
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Affiliation(s)
- Luiz G S Branco
- Dental School of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
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10
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Zwemer CF, Song MY, Carello KA, D'Alecy LG. Strain differences in response to acute hypoxia: CD-1 versus C57BL/6J mice. J Appl Physiol (1985) 2007; 102:286-93. [PMID: 16916919 DOI: 10.1152/japplphysiol.00536.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Some mammals respond to hypoxia by lowering metabolic demand for oxygen and others by maximizing efficiency of oxygen usage: the former strategy is generally held to be the more effective. We describe within the same species one outbred strain (CD-1) that lowers demand and another inbred strain (C57BL/6J) that maximizes oxygen efficiency to markedly extend hypoxic tolerance. Unanesthetized adult male mice ( Mus musculus, CD-1 and C57BL/6J) between 20 and 35 g were used. Sham-conditioned (SC) C57BL/6J mice survived severe hypoxia (4.5% O2, balance N2) roughly twice as long as SC CD-1 mice (median 211 and 93.5 s, respectively; P < 0.0001). Following acute hypoxic conditioning (HC), C57BL/6J mice survived subsequent hypoxia 10 times longer than HC CD-1 mice (median 2,198 and 238 s respectively; P < 0.0001). Therefore, C57BL/6J mice are both naturally more tolerant to hypoxia and show a greater increase in hypoxic tolerance in response to hypoxic conditioning. Indirect calorimetry indicates that CD-1 mice lower mass-specific oxygen consumption (V̇′o2 in ml O2·kg−1·min−1) and carbon dioxide production (V̇′co2 in ml CO2·kg−1·min−1) in response to HC ( P = 0.002 and P < 0.0001, respectively), but C57BL/6J mice maintain V̇′o2 and V̇′co2 after HC. Respiratory exchange ratio and fluorometric assay of plasma ketones suggest that C57BL/6J mice rapidly switch to ketone metabolism, a more efficient substrate, while CD-1 mice reduce overall metabolic activity. We conclude that under severe hypoxia in mice, switching fuel, possibly to ketones, while maintaining V̇′o2, may confer a greater survival advantage than simply lowering demand.
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Affiliation(s)
- Charles F Zwemer
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, USA
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11
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Song MY, Zwemer CF, Whitesall SE, D'Alecy LG. Acute and conditioned hypoxic tolerance augmented by endothelial nitric oxide synthase inhibition in mice. J Appl Physiol (1985) 2006; 102:610-5. [PMID: 17068215 DOI: 10.1152/japplphysiol.00894.2006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To identify a possible role for nitric oxide (NO) in acute hypoxic tolerance (HT) we measured hypoxic survival time (HST), effect of hypoxic conditioning (HC), and survival following hypoxic conditioning while blocking or mimicking the action of nitric oxide synthase (NOS). To inhibit NOS, CD-1 mice were given supplemental endogenous NOS inhibitor asymmetrical dimethylarginine (ADMA) or a synthetic NOS inhibitor N(omega)-nitro-L-arginine (L-NNA), both of which nonselectively inhibit three of the isoforms of NOS [inducible (iNOS), neuronal (nNOS), and endothelial NOS (eNOS)]. ADMA (10 mg/kg i.p.) or saline vehicle was given 5 min before HST testing. L-NNA was given orally at 1 g/l in drinking water with tap water as the control for 48 h before testing. Both ADMA and L-NNA significantly increased HST and augmented the HC effect on HST. Neither the nNOS selective inhibitor 7-nitroindazole (7-NI) nor the iNOS selective inhibitor N-{[3-(aminomethyl)phenyl]methyl}-enthanimidamide (1400W) had a statistically significant effect on HST or HT. The NO donor, 3-morpholinosydnoeimine, when given alone did not significantly decrease HT, but it did mitigate the increased HT effect of L-NNA. These data confirm that acute hypoxic conditioning increases HT and that NOS inhibition by endogenous (ADMA) and a synthetic NOS inhibitor (L-NNA) further increases HT, whereas iNOS and nNOS inhibition does not, suggesting that it is the inhibition of eNOS that mediates enhancement of HT.
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Affiliation(s)
- Michael Y Song
- College of Literature, Science and the Arts, University of Michigan, Ann Arbor, Michigan, USA
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12
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McGuire M, Zhang Y, White DP, Ling L. Chronic intermittent hypoxia enhances ventilatory long-term facilitation in awake rats. J Appl Physiol (1985) 2003; 95:1499-508. [PMID: 12819226 DOI: 10.1152/japplphysiol.00044.2003] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined the effect of chronic intermittent hypoxia (CIH: 5 min 11-12% O2/5 min air, 12 h/night, 7 nights) on ventilatory long-term facilitation (LTF) and determined the persistence period of this CIH effect in awake rats. LTF, elicited by 5 or 10 episodes of 5 min 12% O2, was measured four times in the same Sprague-Dawley rats by plethysmography, before and 8 h, 3 days, and 7 days after CIH treatment. Resting ventilation was unchanged after CIH. Five episodes of 12% O2 did not initially elicit LTF but elicited LTF (23.5 +/- 1.4% above baseline) 8 h after CIH, which partially remained at 3 days (11.4 +/- 2.2%, P < 0.05) and disappeared at 7 days. Ten episodes initially elicited LTF (17.7 +/- 1.1%, 45-min duration) and elicited an enhanced LTF (29.1 +/- 1.5%, 75 min) 8 h after CIH. These results demonstrated that CIH enhanced ventilatory LTF in conscious, freely behaving rats in two ways: 1) a previously ineffective protocol induced LTF; and 2) LTF magnitude was increased and LTF duration prolonged, and this CIH effect on LTF persisted for at least 3 days.
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Affiliation(s)
- Michelle McGuire
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave., Boston, MA 02115, USA
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Patel HH, Hsu A, Gross GJ. Attenuation of heat shock-induced cardioprotection by treatment with the opiate receptor antagonist naloxone. Am J Physiol Heart Circ Physiol 2002; 282:H2011-7. [PMID: 12003805 DOI: 10.1152/ajpheart.00828.2001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Whole body hyperthermia induces heat shock proteins (HSPs), which confer cardioprotection. Several opioid receptor subtypes are expressed in the heart and are linked to cardioprotection; however, no one has attempted to link the protection elicited by heat stress (HS) to opioids. Therefore, we investigated the effect of an opiate receptor antagonist, naloxone, on HS-induced cardioprotection. Anesthetized Sprague-Dawley rats were subjected to HS (42 degrees C for 20 min) with and without naloxone pretreatment and were allowed to recover for 48 h. They then underwent 30 min of ischemia followed by 2 h of reperfusion. An acute HS group was given an intravenous bolus of naloxone (3 mg/kg) 10 min before index ischemia. Infarct size (IS), expressed as a percentage of the area at risk (IS/AAR), was determined. The right heart was excised for analysis of HSP content by Western blot. Heat-shocked rats showed significant reductions in IS/AAR versus control (16 +/- 3 vs. 58 +/- 4%, P < 0.001). Pretreatment with naloxone before HS attenuated the protective effects in a dose-dependent fashion, with significant attenuation of protection occurring at 15 mg/kg naloxone versus heat shock (42 +/- 6 vs. 16 +/- 3%, P < 0.001). Acute treatment with naloxone (3 mg/kg) 48 h after recovery from HS also significantly attenuated the delayed protective effect (47 +/- 4 vs. 16 +/- 3%, P < 0.001). No difference was seen in the level of HSP70 induced in the different groups. We conclude that heat shock-induced cardioprotection can be attenuated by naloxone, an opiate receptor antagonist, without reducing the levels of certain HSPs. These results suggest there may be a link between the endogenous release of opioids and HS that mediates cardioprotection.
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Affiliation(s)
- Hemal H Patel
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Abstract
Hypoxia elicits an array of compensatory responses in animals ranging from protozoa to mammals. Central among these responses is anapyrexia, the regulated decrease of body temperature. The importance of anapyrexia lies in the fact that it reduces oxygen consumption, increases the affinity of hemoglobin for oxygen, and blunts the energetically costly responses to hypoxia. The mechanisms of anapyrexia are of intense interest to physiologists. Several substances, among them lactate, adenosine, opioids, and nitric oxide, have been suggested as putative mediators of anapyrexia, and most appear to act in the central nervous system. Moreover, there is evidence that the drop in body temperature in response to hypoxia, unlike the ventilatory response to hypoxia, does not depend on the activation of peripheral chemoreceptors. The current knowledge of the mechanisms of hypoxia-induced anapyrexia are reviewed.
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Affiliation(s)
- Alexandre A Steiner
- Department of Morphology, Estomatology and Physiology, Dental School of Ribeirão Preto, SP, Brazil.
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Neubauer JA. Invited review: Physiological and pathophysiological responses to intermittent hypoxia. J Appl Physiol (1985) 2001; 90:1593-9. [PMID: 11247965 DOI: 10.1152/jappl.2001.90.4.1593] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This mini-review summarizes the physiological adaptations to and pathophysiological consequences of intermittent hypoxia with special emphasis given to the pathophysiology associated with obstructive sleep apnea. Intermittent hypoxia is an effective stimulus for evoking the respiratory, cardiovascular, and metabolic adaptations normally associated with continuous chronic hypoxia. These adaptations are thought by some to be beneficial in that they may provide protection against disease as well as improve exercise performance in athletes. The long-term consequences of chronic intermittent hypoxia may have detrimental effects, including hypertension, cerebral and coronary vascular problems, developmental and neurocognitive deficits, and neurodegeneration due to the cumulative effects of persistent bouts of hypoxia. Emphasis is placed on reviewing the available data on intermittent hypoxia, making extensions from applicable information from acute and chronic hypoxia studies, and pointing out major gaps in information linking the genomic and cellular responses to intermittent hypoxia with physiological or pathophysiological responses.
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Affiliation(s)
- J A Neubauer
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903-0019, USA.
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Bishop B, Silva G, Krasney J, Salloum A, Roberts A, Nakano H, Shucard D, Rifkin D, Farkas G. Circadian rhythms of body temperature and activity levels during 63 h of hypoxia in the rat. Am J Physiol Regul Integr Comp Physiol 2000; 279:R1378-85. [PMID: 11004007 DOI: 10.1152/ajpregu.2000.279.4.r1378] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hypothermic response of rats to only brief ( approximately 2 h) hypoxia has been described previously. The present study analyzes the hypothermic response in rats, as well as level of activity (L(a)), to prolonged (63 h) hypoxia at rat thermoneutral temperature (29 degrees C). Mini Mitter transmitters were implanted in the abdomens of 10 adult Sprague-Dawley rats to continuously record body temperature (T(b)) and L(a). After habituation for 7 days to 29 degrees C and 12:12-h dark-light cycles, 48 h of baseline data were acquired from six control and four experimental rats. The mean T(b) for the group oscillated from a nocturnal peak of 38.4 +/- 0.18 degrees C (SD) to a diurnal nadir of 36.7 +/- 0.15 degrees C. Then the experimental group was switched to 10% O(2) in N(2). The immediate T(b) response, phase I, was a disappearance of circadian rhythm and a fall in T(b) to 36.3 +/- 0.52 degrees C. In phase II, T(b) increased to a peak of 38.7 +/- 0.64 degrees C. In phase III, T(b) gradually decreased. At reoxygenation at the end of the hypoxic period, phase IV, T(b) increased 1.1 +/- 0.25 degrees C. Before hypoxia, L(a) decreased 70% from its nocturnal peak to its diurnal nadir and was entrained with T(b). With hypoxia L(a) decreased in phase I to essential quiescence by phase II. L(a) had returned, but only to a low level in phase III, and was devoid of any circadian rhythm. L(a) resumed its circadian rhythm on reoxygenation. We conclude that 63 h of sustained hypoxia 1) completely disrupts the circadian rhythms of both T(b) and L(a) throughout the hypoxic exposure, 2) the hypoxia-induced changes in T(b) and L(a) are independent of each other and of the circadian clock, and 3) the T(b) response to hypoxia at thermoneutrality has several phases and includes both hypothermic and hyperthermic components.
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Affiliation(s)
- B Bishop
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214, USA.
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