The effect of alpha-adrenolytics on the levels of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in rat's brain.

Alpha-Adrenolytics (ABA)-phenoxybenzamine, phentolamine and aceperone-increase 5-hydroxyindoleacetic (5-HIAA) acid content in rat's brain. At the same time, these compounds either increase or do not affect 5-hydroxytryptamine (5-HT) level. Moreover, they potentiate L-dopa and reserpine-induced increase in 5-HIAA level and antagonized clonidine-induced decrease in 5-HIAA content. The experiments with probenecid indicate that the observed increase in 5-HIAA does not result from the deficient elimination of the metabolite from brain. The increase in 5-HT turnover in brain, due to ABA, is suggested.