Potentiated endothelin-1-induced phosphoinositide hydrolysis in atria and mesenteric artery of DOCA-salt hypertensive rats.
The effect of endothelin-1 on the phosphoinositide pathway was studied in slices of atria and mesenteric artery from normotensive and hypertensive (DOCA-salt) rats. Endothelin-1 induced a dose-dependent increase in inositol monophosphate production in both groups, but the reactivity of the phosphoinositide pathway was enhanced in DOCA-salt hypertensive rats. Endothelin-1 was more potent than noradrenaline and activation by these two agonists combined was additive. The phosphoinositide activation induced by endothelin-1 was independent of extracellular calcium, and was not prevented by nifedipine treatment or by removing calcium from the incubation medium. Endothelin-1 is a potent direct activator of the phosphoinositide pathway in cardiovascular tissues, and this effect is potentiated in DOCA-salt hypertension.
de Champlain
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J
Départment de Physiologie, Faculté de Médecine, Université de Montréal, Quebec, Canada.
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Papin
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D000818:Animals; D003900:Desoxycorticosterone; D004357:Drug Synergism; D016232:Endothelins; D004730:Endothelium, Vascular / Q000502:physiology*; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism; D006868:Hydrolysis / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride
D016232:Endothelins; D010455:Peptides; D010716:Phosphatidylinositols; D003900:Desoxycorticosterone; D012965:Sodium Chloride; D009638:Norepinephrine