Effects of chronic ethanol consumption on alpha-adrenergic-induced contractions and endothelium-dependent relaxations in rat thoracic aorta.
The effects of chronic oral administration of ethanol (7.2% daily during 24 weeks) on the contractions induced by phenylephrine (Phe) and the endothelium-dependent relaxation responses to acetylcholine (ACh) were studied in rat thoracic aorta. Ethanol pretreatment significantly attenuated the contractile responses to Phe, resulting in parallel shift of the concentration-response curve to the right. EC(50)values of Phe were 64.6+/-11.2 and 95.5+/-8.5 nmol l(-1)in control and ethanol-fed rats, respectively. On the other hand, either calcium-induced contractions or relaxation responses to ACh and sodium nitroprusside were similar in the vessels of the control and ethanol-treated rats. These results suggest that chronic ethanol ingestion significantly attenuates the alpha(1)-adrenergic-induced contractions but does not affect the relaxation responses mediated by nitric oxide in rat aortic rings.
Sahna
E
E
Department of Pharmacology, Faculty of Medicine, In]on]u University, Malatya, 44069, Turkey.
Kurcer
Z
Z
Ozturk
F
F
Cengiz
N
N
Vardi
N
N
Birincioglu
M
M
Olmez
E
E
D000109:Acetylcholine / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology; D002118:Calcium / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects
D000316:Adrenergic alpha-Agonists; D009599:Nitroprusside; D010656:Phenylephrine; D009569:Nitric Oxide; D000109:Acetylcholine; D002118:Calcium