Effect of acute and chronic ethanol on the agonist responses of vascular smooth muscle.
We studied the effect of ethanol in vitro on the response of isolated rat aortas to phenylephrine and angiotensin II. We also examined the effect of chronic ethanol consumption on the phenylephrine response and the effect of ethanol in vitro on that response during the development of ethanol-induced hypertension. In acute experiments the depression of the phenylephrine dose-response produced by ethanol in vitro was greater than that for angiotensin II. Comparing the depression of these agonist dose-responses by ethanol to the depression by the receptor blockers, verapamil, prazosin and saralasin, suggests that ethanol may act like an alpha 1-adrenoceptor blocker. During chronic ethanol consumption two opposing changes occurred: (1) desensitization to phenylephrine during weeks 6-18 and, (2) tolerance to depression by ethanol in vitro during weeks 4-10. These opposing changes may cancel each other which suggests that the hypertension due to chronic ethanol consumption is probably not due to an action of ethanol on the vasculature.
Strickland
J A
JA
Department of Pharmacology, School of Medicine, East Carolina University, Greenville, North Carolina 27858.
Wooles
W R
WR
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000804:Angiotensin II; D010656:Phenylephrine; D000431:Ethanol