title: Key role of endothelium in the eNOS-dependent cardioprotection with exercise training.
abstract: Modulation of endothelial nitric oxide synthase (eNOS) activation is recognized as a main trigger of the cardioprotective effects of exercise training on heart vulnerability to ischemia-reperfusion (IR). However, this enzyme is expressed both in coronary endothelial cells and cardiomyocytes and the contribution of each one to such cardioprotection has never been challenged. The aim of this study was to investigate the role of eNOS from the cardiomyocytes vs. the endothelium in the exercise cardioprotection. Male Wistar rats were assigned to a chronic aerobic training (Ex) (vs. sedentary group; Sed) and we investigated the role of eNOS in the effects of exercise on sensitivity to IR or anoxia-reoxygenation (A/R) at whole heart, isolated cardiomyocytes and left coronary artery (LCA) levels. We observed that exercise increased eNOS activation (Ser1177 phosphorylation) and protein S-nitrosylation in whole heart but not at cardiomyocyte level, suggesting the specific target of endothelial cells by exercise. Consistently, in isolated cardiomyocytes submitted to the A/R procedure, exercise reduced cell death and improved cells contractility, but independently of the eNOS pathway. Next, to evaluate the contribution of endothelial cells in exercise cardioprotection, LCA were isolated before and after an IR procedure performed on Langendorff hearts. Exercise improved basal relaxation sensitivity to acetylcholine and markedly reduced the alteration of endothelium-dependent coronary relaxation induced by IR. Furthermore, inactivation of coronary endothelial cells activity just before IR, obtained with a bolus of Triton X-100, totally suppressed cardioprotective effects of exercise on both left ventricular functional recovery after IR and infarct size, whereas no effect of Triton X-100 was observed in Sed group. In conclusion, these results show that coronary endothelial cells rather than cardiomyocytes play a key role in the eNOS-dependent cardioprotection of exercise.
authors.affiliation: CNRS UMR9214, INSERM U1046, Université de Montpellier, F-34295 Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Farah
authors.affiliation: EA4278, LaPEC, Université d'Avignon, F-84000 Avignon, France; CAPES Foundation, Ministry of Education of Brazil, Brasília/DF 70040-020, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Nascimento
authors.affiliation: EA4278, LaPEC, Université d'Avignon, F-84000 Avignon, France.
authors.forename: G
authors.initials: G
authors.lastname: Bolea
authors.affiliation: EA4278, LaPEC, Université d'Avignon, F-84000 Avignon, France.
authors.forename: G
authors.initials: G
authors.lastname: Meyer
authors.affiliation: EA4278, LaPEC, Université d'Avignon, F-84000 Avignon, France.
authors.forename: S
authors.initials: S
authors.lastname: Gayrard
authors.affiliation: CNRS UMR9214, INSERM U1046, Université de Montpellier, F-34295 Montpellier, France.
authors.forename: A
authors.initials: A
authors.lastname: Lacampagne
authors.affiliation: CNRS UMR9214, INSERM U1046, Université de Montpellier, F-34295 Montpellier, France. Electronic address: olivier.cazorla@inserm.fr.
authors.forename: O
authors.initials: O
authors.lastname: Cazorla
authors.affiliation: EA4278, LaPEC, Université d'Avignon, F-84000 Avignon, France. Electronic address: cyril.reboul@univ-avignon.fr.
authors.forename: C
authors.initials: C
authors.lastname: Reboul
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004727:Endothelium / Q000378:metabolism*; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation; D010805:Physical Conditioning, Animal; D051381:Rats; D015398:Signal Transduction
chemical_list: D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III
keywords: Cardioprotection; Coronary artery; Exercise; Ischemia-reperfusion; Myocytes; eNOS