The influence of alkaline elements on the metabolism of 5-hydroxytryptamine in rat's brain.

A single or four time-administration of Li, Na, K, Rb and Cs chlorides at the doses of 2-5 and 5 mEq/kg ip does not significantly affect 5-HT level. The level of 5-hydroxyindoleacetic acid (5-HIAA) increase only after the administration of LiCl. This increase occurs already after 1 hr and persists up to 24 hrs after the last injection. LiCl given together with probenecid induces the increase in 5-HIAA level greater than that after probenecid alone. The decrease in 5-HIAA level after pargyline-induced inhibition in MAO is more rapid in animals submitted to two action of Li. The increase 5-HIAA level in rat's brain results from Li ions-increased 5-HT turnover.