THE SYMPATHOMIMETIC ACTIVITY OF FENFLURAMINE HYDROCHLORIDE ON RAT VAS DEFERENS

Open Access
Publisher Website
Google Scholar
Abstract
1 The peripheral, pharmacological effects of the anorexigenic agent, fenfluramine hydrochloride, have been investigated on rat isolated vas deferens. 2 Characteristic spiked contractions were observed within 2 to 3 min after exposure to fenfluramine; these contractions reached a rate of around 13 per min and were of variable height. 3 Pre-treatment of vasa with the indirectly acting sympathomimetic amine, tyramine, greatly reduced both the height and rate of contraction induced by fenfluramine. 4 The uptake inhibitor, desipramine, required a concentration in excess of 10 μM to affect fenfluramine-induced contractions. Effects of desipramine on fenfluramine contractions were of equal magnitude whether desipramine was administered before fenfluramine or at the height of the fenfluramine-induced contractions. 5 Pre-treatment with debrisoquine (0.5 mM), reduced the contractions in response to fenfluramine over a period of time. 6 Fenfluramine, added to vasa from rats which had been injected intraperitoneally with 5 mg/kg reserpine 24 h and 48 h previously, failed to induce its characteristic contractions. 7 It is concluded that fenfluramine can be classed as an indirectly acting sympathomimetic amine on peripheral adrenergic nerve terminals.