INHIBITION OF THE TRANSPORT OF 5‐HYDROXYINDOLEACETIC ACID FROM BRAIN BY ETHANOL¹

Abstract

Abstract —The injection of ethanol in mice produced a transient rise in 5‐hydroxyindoleacetic acid (5‐HIAA) levels in brain. However, no concomitant changes in serotonin (5‐HT) levels were noted. In an attempt to explain the biochemical mechanism by which ethanol produced this effect, uptake of tryptophan by brain, serotonin turnover in brain, and transport of 5‐HIAA from brain were investigated. No changes in tryptophan levels or uptake into brain of ethanol‐treated mice were noted. Ethanol 3 g/kg was found to decrease serotonin turnover. Ethanol was also demonstrated to inhibit the removal of 5‐HIAA from the central nervous system, and was found to be an inhibitor of 5‐HIAA uptake by isolated choroid plexus. The inhibition of biogenic acid transport was noted even at sub‐hypnotic levels of ethanol.