The effects of ethanol on the efflux and release of norepinephrine and 5-hydroxytryptamine from slices of rat hypothalamus

Abstract

Studies were done to determine the effects of ethanol on release of norepinephrine, dopamine and 5-hydroxytryptamine from nerve terminals in the central nervous system. Superfused slices of rat hypothalamus were used in these studies and endogenous amines in the superfusate were quantitated using HPLC with electrochemical detection. In these experiments ‘release’ of transmitters was studied in the presence of amitriptyline to block neuronal uptake of amines, whereas ‘efflux’ was measured in its absence. A highly intoxicating concentration of ethanol (69.6 mM, 320 mg%) increased the K+-evoked release of norepinephrine, dopamine and serotonin without affecting basal release. Since this concentration of ethanol increased the basal efflux but not the basal release of 5-hydroxytryptamine, it appeared that neuronal uptake of 5-hydroxytryptamine under basal conditions may also be inhibited by intoxicating levels of ethanol.