title: Beneficial effects of isometric strength training on endothelial dysfunction in rats.
abstract: Using female 4-week-old Sprague-Dawley rats, we investigated the effects of 14 weeks of progressive strength isometric training on endothelium dysfunction after estrogen deficiency. We also proposed possible mechanism(s) by which such training acted on endothelium-dependent vasodilation in thoracic aortic rings. Rats were randomly divided into 4 groups of 8 rats: a sham operated group, an ovariectomized sedentary group receiving 17beta-estradiol vehicle s.c. daily, an ovariectomized sedentary group receiving a daily injection of 20 microg.kg(-1) 17beta-estradiol s.c., and an ovariectomized exercised group receiving daily s.c. vehicle. Vascular reactivity of aortic rings have been evaluated by a cumulative dose of acetylcholine (ACh), in the presence or absence of L-NAME (N-nitro-L-arginine methyl ester), indomethacin, thapsigargin, iberiotoxin, apamin, and tetraethylammonium. Ovariectomy markedly decreased the relaxation caused by ACh, whereas 17beta-estradiol treatment induced a significant increase in the relaxation elicited by ACh. Isometric exercise enhanced relaxation due to ACh. This enhancement was attenuated in the presence of L-NAME, indomethacin, thapsigargin, iberiotoxin, and apamin. Our data indicated, for the first time, that the endothelium-dependent relaxant response to ACh was markedly improved in trained ovariectomized rats. This increased vasodilation is mediated by nitric oxide, cyclooxygenase, sarco-endoplasmic reticulum Ca2+-ATPase pathways, and endothelium-derived hyperpolarizing factor. Finally, this study suggested that resistance training may provide benefits in addressing vascular dysfunction consequent to a decline in estrogen levels after menopause. However, any benefits for age-related vascular dysfunction remain to be demonstrated.
authors.affiliation: UFR STAPS Besançon, 31 chemin de l'Epitaphe 25000 Besançon, Université de Franche-Comté, France. helene.figard@tiscali.fr
authors.forename: Hélène
authors.initials: H
authors.lastname: Figard
authors.forename: Vincent
authors.initials: V
authors.lastname: Gaume
authors.forename: Fabienne
authors.initials: F
authors.lastname: Mougin
authors.forename: Céline
authors.initials: C
authors.lastname: Demougeot
authors.forename: Alain
authors.initials: A
authors.lastname: Berthelot
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000502:physiology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000008:administration & dosage; D004967:Estrogens / Q000502:physiology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D007537:Isometric Contraction / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010052:Ovariectomy; D010805:Physical Conditioning, Animal / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D004967:Estrogens; D009569:Nitric Oxide; D004958:Estradiol; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; D000252:Calcium-Transporting ATPases; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin