Functional assessment of vascular reactivity after chronic intermittent hypoxia in the rat.
We recently developed a model of chronic intermittent hypoxia (CIH) (FiO2 5%, 8 h/day, 35 days) in the rat that was associated with an increased infarction in isolated heart. The aim of the present study was to characterize its functional consequences on vasoreactivity. Aorta and carotid artery were studied using organ bath technique while mesenteric vascular bed was perfused. In the three vascular beds, relaxation to acetylcholine was similar in CIH and control normoxic (NX) rats. Contractions to noradrenaline and angiotensin II were similar between CIH and NX rats. In contrast, contraction to endothelin-1 was increased by 17% (P < 0.05) in carotid artery from CIH rats. Indomethacin pre-treatment reduced by 24% (P < 0.001) contraction to endothelin-1 in carotid artery from CIH rats only. These data suggested that 35-day CIH-exposure induced no change in endothelial function of aorta, carotid artery and mesenteric bed. In contrast, CIH-exposure induced an increased contractile response to endothelin-1 in carotid artery, presumably owing to the release of constrictor cyclooxygenase-derived products.
Laboratoire HP2, Hypoxie Physio-Pathologie Respiratoire et Cardiovasculaire, Faculté de Médecine-Pharmacie, Université Grenoble I, Inserm Espri EA 3745, France.
Blandine
B
Lefebvre
Diane
D
Godin-Ribuot
Marie
M
Joyeux-Faure
Françoise
F
Caron
Germain
G
Bessard
Patrick
P
Lévy
Françoise
F
Stanke-Labesque
D000704:Analysis of Variance; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000503:physiopathology*; D002339:Carotid Arteries / Q000187:drug effects / Q000503:physiopathology*; D002908:Chronic Disease; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D019332:Endothelin-1 / Q000494:pharmacology; D002534:Hypoxia, Brain / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000503:physiopathology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D011189:Potassium Chloride