Effect of ethanol on [3H]Dopamine release in rat nucleus accumbens and striatal slices

Ethanol (10–200 mM) transiently increased tritium overflow from superfused rat nucleus accumbens slices previously incubated with ³H]dopamine (DA) and ¹⁴C]choline. The effect was greater in striatal tissue and did not appear to be a non-specific membrane effect since ¹⁴C]acetylcholine (ACh) release was not affected. Lack of antagonism by picrotoxin suggested that -aminobutyric acid (GABA) receptors were not involved. Calcium was not a requirement and the DA uptake blocker, nomifensine, was without effect. Ethanol appeared to be causing ³H]DA release into the cytoplasm. K⁺-stimulated release of ³H]DA and ¹⁴C]ACh from nucleus accumbens and striatal slices was not affected. Clonidine-mediated inhibition of the K⁺-evoked release of ³H]DA remained unaltered. Ethanol attenuated the isoproterenol-induced enhancement of ³H]DA release. Ethanol therefore appeared to interact with components of the DA terminal causing a transient increase in the release of neurotransmitter without impairing K⁺-evoked release but apparently interfering with the isoproterenol-induced effect.