[Effect of chronic alcohol consumption on activity of enkephalinase A in rat striatum, hypothalamus and midbrain]

A modified procedure is developed for estimation of encephalinase A activity in rough membrane material from rat brain; the accuracy of the procedure was about +/- 5% and sensitivity--0.2 X 10(-15)M of 3H-Tyr-Gly-Gly per min if labelled Leu-encephalin was used as a substrate. Activity of encephalinase A in midbrain and hypothalamus was increased by 10% and in striatum--by 25% after chronic consumption of alcohol within 6 weeks. Rates of specific binding of 3H-Leu-encephalin with opiate receptors in the brain departments studied of the alcohol-treated rats were similar to those of control values. Encephalinase A appears to participate in development of dependence on alcohol or tolerance to it.