title: Suppression by ethanol of pressor response caused by the inhibition of nitric oxide synthesis.
abstract: The effects of ethanol on mean arterial pressure (MAP) and heart rate (HR) responses to the nitric oxide synthase inhibitor, NG-nitro-L-arginine, and to angiotensin II and noradrenaline were studied in rats. I.V. bolus injections of NG-nitro-L-arginine dose dependently increased MAP in vehicle-pretreated rats, with a maximum increase of 56 +/- 7 mm Hg and an ED50 of 3.8 +/- 0.4 mg/kg, respectively. I.v. infusions of ethanol dose dependently reduced maximum MAP response to NG-nitro-L-arginine, with a Ki of 96 +/- 8 mg/kg per min but did not alter the ED50. Ethanol (48 mg/kg per min) did not modify the MAP response to i.v. bolus injections of angiotensin II (0.02-1.28 micrograms/kg) or noradrenaline (0.25-16 micrograms/kg). However, ethanol attenuated the reflex HR responses of NG-nitro-L-arginine and angiotensin II but not that of noradrenaline. The results demonstrate that ethanol selectively but non-competitively inhibits the MAP response to NG-nitro-L-arginine, suggesting an interaction between ethanol and the L-arginine/nitric oxide pathway.
authors: Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
authors: Y X
authors: YX
authors: Wang
authors: C C
authors: CC
authors: Pang
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects; D007275:Injections, Intravenous; D009569:Nitric Oxide / Q000378:metabolism; D019335:Nitroarginine; D009638:Norepinephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000804:Angiotensin II; D019335:Nitroarginine; D009569:Nitric Oxide; D000431:Ethanol; D001120:Arginine; D009638:Norepinephrine