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Chovanec M, Ďurišová J, Vajnerová O, Baňasová A, Vízek M, Žaloudíková M, Uhlík J, Krása K, Herget J, Hampl V. Simple model of pulmonary hypertension secondary to left heart pressure overload induced by partial intravascular occlusion of the ascending aorta. Am J Physiol Lung Cell Mol Physiol 2024; 327:L371-L381. [PMID: 39010823 DOI: 10.1152/ajplung.00243.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 06/27/2024] [Accepted: 06/30/2024] [Indexed: 07/17/2024] Open
Abstract
Pulmonary hypertension is a group of diseases characterized by elevated pulmonary artery pressure and pulmonary vascular resistance with significant morbidity and mortality. The most prevalent type is pulmonary hypertension secondary to left heart disease (PH-LHD). The available experimental models of PH-LHD use partial pulmonary clamping by technically nontrivial open-chest surgery with lengthy recovery. We present a simple model in which the reduction of the cross-sectional area of the ascending aorta is achieved not by external clamping but by partial intravascular obstruction without opening the chest. In anesthetized rats, a blind polyethylene tubing was advanced from the right carotid artery to just above the aortic valve. The procedure is quick and easy to learn. Three weeks after the procedure, left heart pressure overload was confirmed by measuring left ventricular end-diastolic pressure by puncture (1.3 ± 0.2 vs. 0.4 ± 0.3 mmHg in controls, mean ± SD, P < 0.0001). The presence of pulmonary hypertension was documented by measuring pulmonary artery pressure by catheterization (22.3 ± 2.3 vs. 16.9 ± 2.7 mmHg, P = 0.0282) and by detecting right ventricular hypertrophy and increased muscularization of peripheral pulmonary vessels. Contributions of a precapillary vascular segment and vasoconstriction to the increased pulmonary vascular resistance were demonstrated, respectively, by arterial occlusion technique and by normalization of resistance by a vasodilator, sodium nitroprusside, in isolated lungs. These changes were comparable, but not additive, to those induced by an established pulmonary hypertension model, chronic hypoxic exposure. Intravascular partial aortic obstruction offers an easy model of pulmonary hypertension induced by left heart disease that has a vasoconstrictor and precapillary component.NEW & NOTEWORTHY We present a new, simple model of a clinically important type of pulmonary hypertension, that induced by left heart failure. Left ventricular pressure overload is induced in rats by inserting a blinded cannula into the ascending aorta via carotid artery access. This partial intravascular aortic obstruction, which does not require opening of the chest and prolonged recovery, causes pulmonary hypertension, which has a precapillary and vasoconstrictor as well as a vascular remodeling component.
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Affiliation(s)
- Milan Chovanec
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- Department of Cardiology, Na Homolce Hospital, Prague, Czech Republic
| | - Jana Ďurišová
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Olga Vajnerová
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Alena Baňasová
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Martin Vízek
- Department of Pathophysiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Marie Žaloudíková
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jiří Uhlík
- Department of Histology and Embryology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Kryštof Krása
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- Department of Internal Medicine, First Faculty of Medicine, Charles University and Military University Hospital, Prague, Czech Republic
| | - Jan Herget
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Václav Hampl
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
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Al-Hilal TA, Hossain MA, Alobaida A, Alam F, Keshavarz A, Nozik-Grayck E, Stenmark KR, German NA, Ahsan F. Design, synthesis and biological evaluations of a long-acting, hypoxia-activated prodrug of fasudil, a ROCK inhibitor, to reduce its systemic side-effects. J Control Release 2021; 334:237-247. [PMID: 33915222 DOI: 10.1016/j.jconrel.2021.04.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023]
Abstract
ROCK, one of the downstream regulators of Rho, controls actomyosin cytoskeleton organization, stress fiber formation, smooth muscle contraction, and cell migration. ROCK plays an important role in the pathologies of cerebral and coronary vasospasm, hypertension, cancer, and arteriosclerosis. Pharmacological-induced systemic inhibition of ROCK affects both the pathological and physiological functions of Rho-kinase, resulting in hypotension, increased heart rate, decreased lymphocyte count, and eventually cardiovascular collapse. To overcome the adverse effects of systemic ROCK inhibition, we developed a bioreductive prodrug of a ROCK inhibitor, fasudil, that functions selectively under hypoxic conditions. By masking fasudil's active site with a bioreductive 4-nitrobenzyl group, we synthesized a prodrug of fasudil that is inactive in normoxia. Reduction of the protecting group initiated by hypoxia reveals an electron-donating substituent that leads to fragmentation of the parent molecule. Under normoxia the fasudil prodrug displayed significantly reduced activity against ROCK compared to its parent compound, but under severe hypoxia the prodrug was highly effective in suppressing ROCK activity. Under hypoxia the prodrug elicited an antiproliferative effect on disease-afflicted pulmonary arterial smooth muscle cells and pulmonary arterial endothelial cells. The prodrug displayed a long plasma half-life, remained inactive in the blood, and produced no drop in systemic blood pressure when compared with fasudil-treated controls. Due to its selective nature, our hypoxia-activated fasudil prodrug could be used to treat diseases where tissue-hypoxia or hypoxic cells are the pathological basis of the disease.
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Affiliation(s)
- Taslim A Al-Hilal
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA; Department of Pharmaceutical Sciences, The University of Texas at El Paso, El Paso, TX, USA
| | - Mohammad Anwar Hossain
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA
| | - Ahmed Alobaida
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA; Department of Pharmaceutics, School of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Farzana Alam
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA
| | - Ali Keshavarz
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA
| | - Eva Nozik-Grayck
- Department of Pediatrics and Medicine, Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kurt R Stenmark
- Department of Pediatrics and Medicine, Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Nadezhda A German
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA
| | - Fakhrul Ahsan
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, USA; Department of Pharmaceutical and Biomedical Sciences, California Northstate University, 9700 West Taron Drive, Elk Grove, CA 95757, USA.
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Mikhael M, Makar C, Wissa A, Le T, Eghbali M, Umar S. Oxidative Stress and Its Implications in the Right Ventricular Remodeling Secondary to Pulmonary Hypertension. Front Physiol 2019; 10:1233. [PMID: 31607955 PMCID: PMC6769067 DOI: 10.3389/fphys.2019.01233] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 09/09/2019] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is a pulmonary vascular disease characterized by increased pulmonary artery pressures. Long standing pulmonary arterial pressure overload leads to right ventricular (RV) hypertrophy, RV failure, and death. RV failure is a major determinant of survival in PH. Oxidative stress has been associated with the development of RV failure secondary to PH. Here we summarize the structural and functional changes in the RV in response to sustained pulmonary arterial pressure overload. Furthermore, we review the pre-clinical and clinical studies highlighting the association of oxidative stress with pulmonary vasculature and RV remodeling in chronic PH. Targeting oxidative stress promises to be an effective therapeutic strategy for the treatment of RV failure.
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Affiliation(s)
- Matthew Mikhael
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Christian Makar
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Amir Wissa
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Trixie Le
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Mansoureh Eghbali
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Soban Umar
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
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Xia X, Peng Y, Lei D, Chen W. Hypercapnia downregulates hypoxia‐induced lysyl oxidase expression in pulmonary artery smooth muscle cells via inhibiting transforming growth factor β1signalling. Cell Biochem Funct 2019; 37:193-202. [PMID: 30917408 DOI: 10.1002/cbf.3390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 02/17/2019] [Accepted: 03/01/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Xiao‐dong Xia
- Department of Respiratory MedicineThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University Wenzhou China
| | - Yan‐ping Peng
- Department of Respiratory MedicineThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University Wenzhou China
| | - Dan Lei
- Department of Respiratory MedicineThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University Wenzhou China
| | - Wei‐qian Chen
- Department of Respiratory MedicineThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University Wenzhou China
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Vajnerova O, Kafka P, Kratzerova T, Chalupsky K, Hampl V. Pregestational diabetes increases fetoplacental vascular resistance in rats. Placenta 2018; 63:32-38. [PMID: 29486854 DOI: 10.1016/j.placenta.2018.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 01/02/2018] [Accepted: 01/04/2018] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Diabetes is a well-known risk factor in pregnancy. Because maternal diabetes involves oxidative stress that is also induced by chronic hypoxia and can alter vascular function, we sought to determine the effects of chronic maternal hyperglycemia on the fetoplacental vasculature in rats and to compare it with the effects of chronic hypoxia. METHODS Diabetes was induced in female rats by a streptozotocin injection at a neonatal age. When these animals reached adulthood, their hyperglycemia was confirmed and they were inseminated. Half of them were exposed to hypoxia (10% O2) for the last week before the delivery. One day before the expected date of delivery, one of their placentae was isolated and perfused. RESULTS Fetoplacental vascular resistance was increased equally by experimental diabetes, chronic hypoxia, and their combination. Fetoplacental perfusion pressure-flow analysis suggested increased resistance in the small vessels in chronic hypoxia and in larger vessels in diabetes. Fetal plasma nitrotyrosine levels, measured as a marker of peroxynitrite (reaction product of superoxide and nitric oxide), mirrored the differences in fetoplacental resistance, suggesting a causative role. Fetoplacental vasoconstrictor reactivity to acute hypoxic stimuli was reduced similarly in all groups. Fasudil, a strong vasodilator agent, reduced fetoplacental vascular resistance similarly in all groups, suggesting that for the observed differences among the groups, the changes in vascular morphology were more important than variances in vascular tone. DISCUSSION Maternal diabetes increases fetoplacental vascular resistance to a similar extent as chronic hypoxia. These stimuli are not additive. Changes in vascular tone are not responsible for these effects.
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Affiliation(s)
- Olga Vajnerova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic.
| | - Petr Kafka
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Anesthesiology and Intensive Care Medicine, Kralovske Vinohrady University Hospital, Prague, Czech Republic
| | - Tereza Kratzerova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Karel Chalupsky
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Vaclav Hampl
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
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Xu D, Li Y, Zhang B, Wang Y, Liu Y, Luo Y, Niu W, Dong M, Liu M, Dong H, Zhao P, Li Z. Resveratrol alleviate hypoxic pulmonary hypertension via anti-inflammation and anti-oxidant pathways in rats. Int J Med Sci 2016; 13:942-954. [PMID: 27994500 PMCID: PMC5165688 DOI: 10.7150/ijms.16810] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/27/2016] [Indexed: 01/10/2023] Open
Abstract
Resveratrol, a plant-derived polyphenolic compound and a phytoestrogen, was shown to possess multiple protective effects including anti-inflammatory response and anti-oxidative stress. Hypoxic pulmonary hypertension (HPH) is a progressive disease characterized by sustained vascular resistance and marked pulmonary vascular remodeling. The exact mechanisms of HPH are still unclear, but inflammatory response and oxidative stress was demonstrated to participate in the progression of HPH. The present study was designed to investigate the effects of resveratrol on HPH development. Sprague-Dawley rats were challenged by hypoxia exposure for 28 days to mimic hypoxic pulmonary hypertension along with treating resveratrol (40 mg/kg/day). Hemodynamic and pulmonary pathomorphology data were then obtained, and the anti-proliferation effect of resveratrol was determined by in vitro assays. The anti-inflammation and anti-oxidative effects of resveratrol were investigated in vivo and in vitro. The present study showed that resveratrol treatment alleviated right ventricular systolic pressure and pulmonary arterial remodeling induced by hypoxia. In vitro experiments showed that resveratrol notably inhibited proliferation of pulmonary arterial smooth muscle cells in an ER-independent manner. Data showed that resveratrol administration inhibited HIF-1 α expression in vivo and in vitro, suppressed inflammatory cells infiltration around the pulmonary arteries, and decreased ROS production induced by hypoxia in PAMSCs. The inflammatory cytokines' mRNA levels of tumor necrosis factor α, interleukin 6, and interleukin 1β were all suppressed by resveratrol treatment. The in vitro assays showed that resveratrol inhibited the expression of HIF-1 α via suppressing the MAPK/ERK1 and PI3K/AKT pathways. The antioxidant axis of Nuclear factor erythroid-2 related factor 2/ Thioredoxin 1 (Nrf-2/Trx-1) was up-regulated both in lung tissues and in cultured PASMCs. In general, the current study demonstrated that resveratrol may prevent pulmonary hypertension through its anti-proliferation, anti-inflammation and antioxidant effects. Hence, the present data may offer novel targets and promising pharmacological perspective for treating hypoxic pulmonary hypertension.
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Affiliation(s)
- Dunquan Xu
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China.; Clinical laboratory, the Eighth Hospital of PLA, Xigaze, 857000, PR China
| | - Yan Li
- Physical Examination Center of Beijing Military Region General Hospital, Beijing, 100700, PR China
| | - Bo Zhang
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Yanxia Wang
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Yi Liu
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Ying Luo
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Wen Niu
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Mingqing Dong
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Manling Liu
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Haiying Dong
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Pengtao Zhao
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
| | - Zhichao Li
- Department of Pathophysiology, Fourth Military Medical University, Xi`an, 710032, PR China
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Mrazkova H, Lischke R, Hodyc D, Herget J. The protective effect of hypercapnia on ischemia-reperfusion injury in lungs. Respir Physiol Neurobiol 2014; 205:42-6. [PMID: 25450116 DOI: 10.1016/j.resp.2014.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 09/16/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
Lifesaving therapy for patients with end-stage lung disease is lung transplantation. However, there are not enough available donors. A relatively new method of transplantation from non-heart-beating donors (NHBDs) allows the treatment of the lung outside the body and could increase the number of suitable lungs. We have focused on hypercapnic ventilation, which has the possibility of reducing reactive oxygen species damage. We used four experimental and two control groups of adult rats. Each experimental group underwent the protocol of NHBD lung harvesting. The lungs were than perfused in an ex vivo model and we measured weight gain, arterial-venous difference in partial pressure of oxygen and perfusion pressure. We observed that hypercapnic ventilation during reperfusion reduces the development of pulmonary oedema and has a protective effect on the oxygen transport ability of the lungs after warm ischemia. The effect of CO2 on pulmonary oedema and on oxygen transport ability after warm ischemia could be of clinical importance for NHBD transplantation.
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Affiliation(s)
- Hana Mrazkova
- 3rd Department of Surgery, University Hospital Motol and 1st Medical School, Charles University in Prague, Prague, Czech Republic.
| | - Robert Lischke
- 3rd Department of Surgery, University Hospital Motol and 1st Medical School, Charles University in Prague, Prague, Czech Republic
| | - Daniel Hodyc
- Department of Physiology, 2nd Medical School, Charles University in Prague, Prague, Czech Republic
| | - Jan Herget
- Department of Physiology, 2nd Medical School, Charles University in Prague, Prague, Czech Republic
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Maarman G, Lecour S, Butrous G, Thienemann F, Sliwa K. A comprehensive review: the evolution of animal models in pulmonary hypertension research; are we there yet? Pulm Circ 2013; 3:739-56. [PMID: 25006392 PMCID: PMC4070827 DOI: 10.1086/674770] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 06/28/2013] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is a disorder that develops as a result of remodeling of the pulmonary vasculature and is characterized by narrowing/obliteration of small pulmonary arteries, leading to increased mean pulmonary artery pressure and pulmonary vascular resistance. Subsequently, PH increases the right ventricular afterload, which leads to right ventricular hypertrophy and eventually right ventricular failure. The pathophysiology of PH is not fully elucidated, and current treatments have only a modest impact on patient survival and quality of life. Thus, there is an urgent need for improved treatments or a cure. The use of animal models has contributed extensively to the current understanding of PH pathophysiology and the investigation of experimental treatments. However, PH in current animal models may not fully represent current clinical observations. For example, PH in animal models appears to be curable with many therapeutic interventions, and the severity of PH in animal models is also believed to correlate poorly with that observed in humans. In this review, we discuss a variety of animal models in PH research, some of their contributions to the field, their shortcomings, and how these have been addressed. We highlight the fact that the constant development and evolution of animal models will help us to more closely model the severity and heterogeneity of PH observed in humans.
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Affiliation(s)
- Gerald Maarman
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Sandrine Lecour
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Ghazwan Butrous
- Pulmonary Vascular Research Institute, Kent Enterprise Hub, University of Kent, Canterbury, United Kingdom
| | - Friedrich Thienemann
- Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Karen Sliwa
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Žaloudíková M, Herget J, Vízek M. Hypercapnia attenuates the hypoxia-induced blunting of the reactivity in chronically hypoxic rats. Physiol Res 2013; 62:585-8. [PMID: 23869897 DOI: 10.33549/physiolres.932565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Chronic hypoxia causes oxidative injury of pulmonary vessels and attenuates their reactivity to different stimuli. When combined with hypercapnia, biochemical markers of this injury are reduced but the effect of concomitant hypoxia and hypercapnia on vascular reactivity is not fully understood. This study was therefore designed to test whether hypercapnia can prevent also the hypoxia-induced loss of reactivity of pulmonary vessels. The reactivity of vessels from rats exposed either to hypoxia or hypoxia combined with hypercapnia was tested using a small vessel myograph (M 500A, Linton, Norfolk, GB). The second and third intrapulmonary branches of pulmonary arteries were isolated under a dissecting microscope from lungs of 8 control rats (group N), 6 rats exposed to hypoxia for 5 days (isobaric, 10 % O(2), group H) and 7 rats exposed to hypoxia combined with hypercapnia for 5 days (10 % O(2), 5 % CO(2), group H+CO(2)). The transmural pressure was set by automatic normalization to 30 mm Hg. The vessel size did not vary among the groups. After stabilization we challenged the vessels twice with KCl (80 mM) and once with PGF(2alpha) (0.1 mM). There were no significant differences in KCl induced contractions among the groups. The responses to PGF(2alpha) were expressed as a ratio to the maximal tension obtained by the exposure to 80 mM KCl. Contractions induced by PGF(2alpha) were markedly reduced in group H (0.07+/-0.02) and in group H+CO(2) (0.26+/-0.03) in comparison with group N (0.83+/-0.07). The vessels of group H responded to PGF(2alpha) less than those of group H+CO(2). However we observed the attenuated reactivity also in group H+CO(2) in comparison with N. Hypercapnia therefore partially blunted the hypoxia-induced loss of reactivity in pulmonary arteries. This finding supports the hypothesis that hypercapnia significantly alters the nature of lung injury induced by chronic hypoxia.
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Affiliation(s)
- M Žaloudíková
- Department of Pathophysiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic.
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Peng G, Ivanovska J, Kantores C, Van Vliet T, Engelberts D, Kavanagh BP, Enomoto M, Belik J, Jain A, McNamara PJ, Jankov RP. Sustained therapeutic hypercapnia attenuates pulmonary arterial Rho-kinase activity and ameliorates chronic hypoxic pulmonary hypertension in juvenile rats. Am J Physiol Heart Circ Physiol 2012; 302:H2599-611. [DOI: 10.1152/ajpheart.01180.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sustained therapeutic hypercapnia prevents pulmonary hypertension in experimental animals, but its rescue effects on established disease have not been studied. Therapies that inhibit Rho-kinase (ROCK) and/or augment nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signaling can reverse or prevent progression of chronic pulmonary hypertension. Our objective in the present study was to determine whether sustained rescue treatment with inhaled CO2 (therapeutic hypercapnia) would improve structural and functional changes of chronic hypoxic pulmonary hypertension. Spontaneously breathing pups were exposed to normoxia (21% O2) or hypoxia (13% O2) from postnatal days 1–21 with or without 7% CO2 (PaCO2 elevated by ∼25 mmHg) or 10% CO2 (PaCO2 elevated by ∼40 mmHg) from days 14 to 21. Compared with hypoxia alone, animals exposed to hypoxia and 10% CO2 had significantly ( P < 0.05) decreased pulmonary vascular resistance, right-ventricular systolic pressure, right-ventricular hypertrophy, and medial wall thickness of pulmonary resistance arteries as well as decreased lung phosphodiesterase (PDE) V, RhoA, and ROCK activity. Rescue treatment with 10% CO2, or treatment with a ROCK inhibitor (15 mg/kg ip Y-27632 twice daily from days 14 to 21), also increased pulmonary arterial endothelial nitric oxide synthase and lung NO content. In contrast, cGMP content and cGMP-dependent protein kinase (PKG) activity were increased by exposure to 10% CO2, but not by ROCK inhibition with Y-27632. In vitro exposure of pulmonary artery smooth muscle cells to hypercapnia suppressed serum-induced ROCK activity, which was prevented by inhibition of PKG with Rp-8-Br-PET-cGMPS. We conclude that sustained hypercapnia dose-dependently inhibited ROCK activity, augmented NO-cGMP-PKG signaling, and led to partial improvements in the hemodynamic and structural abnormalities of chronic hypoxic PHT in juvenile rats. Increased PKG content and activity appears to play a major upstream role in CO2-induced suppression of ROCK activity in pulmonary arterial smooth muscle.
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Affiliation(s)
- Gary Peng
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Julijana Ivanovska
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Crystal Kantores
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Todd Van Vliet
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
| | - Doreen Engelberts
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Brian P. Kavanagh
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- the 4Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Masahiro Enomoto
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Jaques Belik
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
| | - Patrick J. McNamara
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Robert P. Jankov
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Ketabchi F, Ghofrani HA, Schermuly RT, Seeger W, Grimminger F, Egemnazarov B, Shid-Moosavi SM, Dehghani GA, Weissmann N, Sommer N. Effects of hypercapnia and NO synthase inhibition in sustained hypoxic pulmonary vasoconstriction. Respir Res 2012; 13:7. [PMID: 22292558 PMCID: PMC3306743 DOI: 10.1186/1465-9921-13-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 01/31/2012] [Indexed: 01/11/2023] Open
Abstract
Background Acute respiratory disorders may lead to sustained alveolar hypoxia with hypercapnia resulting in impaired pulmonary gas exchange. Hypoxic pulmonary vasoconstriction (HPV) optimizes gas exchange during local acute (0-30 min), as well as sustained (> 30 min) hypoxia by matching blood perfusion to alveolar ventilation. Hypercapnia with acidosis improves pulmonary gas exchange in repetitive conditions of acute hypoxia by potentiating HPV and preventing pulmonary endothelial dysfunction. This study investigated, if the beneficial effects of hypercapnia with acidosis are preserved during sustained hypoxia as it occurs, e.g in permissive hypercapnic ventilation in intensive care units. Furthermore, the effects of NO synthase inhibitors under such conditions were examined. Method We employed isolated perfused and ventilated rabbit lungs to determine the influence of hypercapnia with or without acidosis (pH corrected with sodium bicarbonate), and inhibitors of endothelial as well as inducible NO synthase on acute or sustained HPV (180 min) and endothelial permeability. Results In hypercapnic acidosis, HPV was intensified in sustained hypoxia, in contrast to hypercapnia without acidosis when HPV was amplified during both phases. L-NG-Nitroarginine (L-NNA), a non-selective NO synthase inhibitor, enhanced acute as well as sustained HPV under all conditions, however, the amplification of sustained HPV induced by hypercapnia with or without acidosis compared to normocapnia disappeared. In contrast 1400 W, a selective inhibitor of inducible NO synthase (iNOS), decreased HPV in normocapnia and hypercapnia without acidosis at late time points of sustained HPV and selectively reversed the amplification of sustained HPV during hypercapnia without acidosis. Hypoxic hypercapnia without acidosis increased capillary filtration coefficient (Kfc). This increase disappeared after administration of 1400 W. Conclusion Hypercapnia with and without acidosis increased HPV during conditions of sustained hypoxia. The increase of sustained HPV and endothelial permeability in hypoxic hypercapnia without acidosis was iNOS dependent.
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Affiliation(s)
- Farzaneh Ketabchi
- Justus-Liebig-University Giessen, University of Giessen & Marburg Lung Center (UGMLC), Excellence Cluster Cardio-Pulmonary System (ECCPS), Medical Clinic II/IV/V, Aulweg 130, 35392 Giessen, Germany
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Xia XD, Xu ZJ, Hu XG, Wu CY, Dai YR, Yang L. Impaired iNOS-sGC-cGMP signalling contributes to chronic hypoxic and hypercapnic pulmonary hypertension in rat. Cell Biochem Funct 2012; 30:279-85. [PMID: 22290599 DOI: 10.1002/cbf.2796] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/30/2011] [Accepted: 12/05/2011] [Indexed: 02/02/2023]
Abstract
Nitric oxide (NO) is an important vascular modulator in the development of pulmonary hypertension. NO exerts its regulatory effect mainly by activating soluble guanylate cyclase (sGC) to synthesize cyclic guanosine monophosphate (cGMP). Exposure to hypoxia causes pulmonary hypertension. But in lung disease, hypoxia is commonly accompanied by hypercapnia. The aim of this study was to examine the changes of sGC enzyme activity and cGMP content in lung tissue, as well as the expression of inducible nitric oxide synthase (iNOS) and sGC in rat pulmonary artery after exposure to hypoxia and hypercapnia, and assess the role of iNOS-sGC-cGMP signal pathway in the development of hypoxic and hypercapnic pulmonary hypertension. Male Sprague-Dawley rats were exposed to hypoxia and hypercapnia for 4 weeks to establish model of chronic pulmonary hypertension. Weight-matched rats exposed to normoxia served as control. After exposure to hypoxia and hypercapnia, mean pulmonary artery pressure, the ratio of right ventricle/left ventricle+septum, and the ratio of right ventricle/body weight were significantly increased. iNOS mRNA and protein levels were significantly increased, but sGC α(1) mRNA and protein levels were significantly decreased in small pulmonary arteries of hypoxic and hypercapnic exposed rat. In addition, basal and stimulated sGC enzyme activity and cGMP content in lung tissue were significantly lower after exposure to hypoxia and hypercapnia. These results demonstrate that hypoxia and hypercapnia lead to the upregulation of iNOS expression, downregulation of sGC expression and activity, which then contribute to the development of pulmonary hypertension.
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Affiliation(s)
- Xiao-dong Xia
- Department of Respiratory Medicine, The Second Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
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