PMID: 42517Jan 1, 1979

The relationships between the cardiovascular effects, alpha- and beta-adrenoceptor blocking actions and plasma concentration of labetalol in doca hypertensive rats

Clinical and Experimental Hypertension : CHE
G M DrewG P Levy

Abstract

The relationships between the cardiovascular effects, alpha- and beta-adrenoceptor blocking actions and plasma concentration of labetalol have been examined in conscious DOCA hypertensive rats. Labetalol (10, 30 and 100 mg/kg p.o.) reduced resting heart rate; blood pressure was reduced only by the two higher doses. The effects lasted 5-24 hours. There was a highly significant correlation between the plasma labetalol concentration and its cardiovascular effects. During the labetalol-induced hypotension and bradycardia the vasopressor responses to intra-arterial injections of phenylephrine were reduced; the tachycardia and vasodepressor responses produced by intra-arterial injections of isoprenaline were also reduced. It is concluded that alpha- and beta-adrenoceptor blockade probably account for the labetalol-induced decreases in resting blood pressure and heart rate respectively.

Citations

Oct 1, 1976·British Journal of Clinical Pharmacology·D A RichardsB N Prichard
Jan 3, 1977·European Journal of Clinical Pharmacology·D A RichardsL E Martin
Jun 1, 1978·European Journal of Pharmacology·I CaveroA G Roach
Dec 1, 1958·Annals of Internal Medicine·F M STURTEVANT
Jul 1, 1960·Journal of Applied Physiology·V POPOVIC, P POPOVIC

Related Concepts

Phenylephrine Hydrochloride
Depression, Chemical
Bradycardia
Diastolic Blood Pressure
Adrenergic alpha-Antagonists
Deoxycorticosterone
Novodrin
Hypertensive Disease
Ethanolamines
Dose-Response Relationship, Drug

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