Effect of acute and chronic ethanol on dopamine synthesis in the caudate nucleus, substantia nigra and frontal cortex

A single oral administration of 3.2 g/kg ethanol to normal rats increased 3,4-dihydroxyphenylacetic acid (DOPAC) content and DOPA formation in the caudate nucleus but had no effect in frontal cortex and substantia nigra and did not modify dopamine (DA) levels in any of the brain regions analyzed. Complete tolerance to the stimulant effect on DOPA formation developed after chronic ethanol-treatment (3.2 g/kg daily for 60 days). However ethanol administration to ethanol dependent rats produces a marked DA depletion and increases DOPAC concentration in the brain areas studied. The present results show that acute and chronic ethanol release DA stores, but only in the acute conditions DA depletion is compensated by enhanced synthesis.