Ethanol inhibition of synaptosomal high-affinity choline uptake.

Ethanol in vitro inhibited synaptosomal sodium-dependent, high-affinity choline uptake, the rate-limiting step in the synthesis of acetylcholine. This inhibition occurred with ethanol concentrations as low as 50 mM, was reversible and was not attributable to ethanol effects on synaptosomal membrane potential. In contrast, ethanol concentrations as high as 400 mM had no effect on synaptosomal high-affinity uptake of gamma-aminobutyric acid, a major inhibitory neurotransmitter in the central nervous system. The observed ethanol inhibition of choline uptake is consistent with suggestions that depression of cholinergic systems is important in acute ethanol intoxication.