Effects of acute ethanol administration on regional serotonin turnover.

Numerous studies show the role of biogenic amines in the effects of ethanol. The present work analyzed the effect of an acute sedative-hypnotic dose of ethanol (4 g/kg) on the levels of tryptophan, serotonin (5-HT) and 5-hydroxyindol-acetic acid (5-HIAA), the serotonin synthesis rate and the 5-HIAA elimination rate in several regions of the brain. The 5-HT synthesis rate was not enhanced by ethanol administration, despite increases in brain tryptophan, 5-HT and 5-HIAA, which were primarily in the medulla-pons. The increased indole levels could be due to inhibition of 5-HIAA elimination from the brain.