Ethanol inhibits veratridine-stimulated sodium uptake in synaptosomes

The effects of ethanol and pentobarbital on voltage-sensitive sodium channels in whole brain (rat) synaptosomes were studied using isotopic flux measurements. Incubation of synaptosomes with ethanol or pentobarbital in vitro inhibited veratridine-stimulated 22Na+ uptake. The effect of ethanol is dose-dependent, occurs at sublethal, pharmacologically relevant concentrations and is fully reversible. These results suggest that ethanol and pentobarbital directly interfere with sodium channel function in nervous tissue. Alterations in sodium channel function may be a possible mechanism for the central nervous system (CNS) depressant action of ethanol and related compounds.