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Heat stress increases endothelium‐dependent relaxations and prevents reperfusion‐induced endothelial dysfunction
Author(s) -
Richard Vincent,
Laude Karine,
Artigues Cecile,
Kaeffer Nathalie,
Henry JeanPaul,
Thuillez Christian
Publication year - 2002
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1046/j.1440-1681.2002.03759.x
Subject(s) - aorta , medicine , acetylcholine , endothelium , nitric oxide , mesenteric arteries , ischemia , isometric exercise , coronary arteries , thoracic aorta , histamine , endothelial dysfunction , vasodilation , endocrinology , chemistry , anesthesia , cardiology , artery
Summary 1. Heat stress has been widely used to stimulate the expression of stress proteins and is associated with various cardiovascular changes, including anti‐ischaemic effects. However, the effect of heat stress on endothelial function is less clear. 2. Heat stress was induced in anaesthetized rats by increasing body temperature to 42°C for 15 min. Twenty‐four hours later, segments of rat aorta and mesenteric and coronary arteries were mounted in organ chambers. 3. Heat stress markedly increased relaxation to acetylcholine (ACh) in all three blood vessels studied, without affecting the response to the nitric oxide (NO) donor sydnonimine‐1. 4. Heat stress also increased aortic relaxation to histamine and the calcium ionophore A23187. 5. In the aorta, an inhibitor of NO synthesis abolished the response to ACh in both control and heat stressed‐rings, whereas a cyclo‐oxygenase inhibitor had no effect. 6. Heat stress also prevented completely the impaired response to ACh in coronary arteries isolated from rats subjected to myocardial ischaemia and reperfusion. 7. Thus, heat stress increases the stimulated release of NO the rat aorta and mesenteric and coronary arteries and prevents reperfusion‐induced injury at the level of the coronary endothelium.