Enkephalinase inhibition by thiorphan and subsequent response of ethanol, normorphine and enkephalins on mouse vas deferens.

In this study, a comparison was made between ethanol, normorphine methionine-enkephalin and [D-ala2] enkephalinamide and the ability of thiorphan, an enkephalinase inhibitor, to potentiate their in vitro activity to inhibit the electrically induced contractions of mouse vas deferens. Thiorphan did not significantly alter the response of either ethanol or normorphine on mouse vas deferens, whereas it significantly potentiated the response of methionine enkephalin.