title: Vascular reactivity in alcoholic rat aortas: in vitro interactions between catecholamines and alcohol.
abstract: To understand the nature of vascular problems of hypertensive and alcoholic subjects, an in vitro interaction between catecholamine and alcohol was investigated in male Sprague-Dawley rats. The descending aortas were isolated from either the control or alcohol treated rats. The aortic strips were cooled rapidly in ice-chilled Krebs-Henseleit (K-H) solution and the aorta was cut into a series of rings of approximately 1 mm width. The rings were fixed under 1 g of resting tension between a force-displacement transducer and anchoring electrodes at 37 degrees C. The rings were equilibrated for an hour with frequent changes of the K-H solution before testing. There was norepinephrine (NE) dose-dependent contraction of the rings, which showed the maximum tension with 1 microM NE. Acetylcholine or carbachol produced slow relaxation. Pretreatment of the rings with 10 microM prazocin prevent the contraction induced by 1 microM NE. Even in the presence of prazocin, 60 mM KCI was able to generate the maximum tension. NE-induced contraction was analyzed in the control K-H solution or in the presence of 1.5, 3.0 and 5.0% of ethanol. Ethanol (1.5%) slowed the rate of rise of the aortic tension without a remarkable compromise of the maximum tension. But, there was a significant reduction in contraction with 3% ethanol. A complete inhibition of contraction was noted with 5% ethanol. However, the effect of ethanol was fully reversible upon washings the aortic rings with K-H solution. Aortic rings prepared from the rats that were fed with alcohol for 30 days were not able to generate the maximum tension with 1 microM NE.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Food and Drug Administration, Center for Drug Evaluation and Research, Rockville, Maryland 20857, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Rhee
authors.forename: B J
authors.initials: BJ
authors.lastname: Song
authors.forename: S
authors.initials: S
authors.lastname: Cushman
authors.forename: S E
authors.initials: SE
authors.lastname: Shoaf
mesh_terms: D000437:Alcoholism / Q000503:physiopathology; D000818:Animals; D001011:Aorta / Q000187:drug effects*; D002217:Carbachol / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology*; D006973:Hypertension / Q000209:etiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D017680:Potassium Compounds / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D017680:Potassium Compounds; D000431:Ethanol; D002217:Carbachol; D009638:Norepinephrine