Abstract

Administration of 1-isopropyl-2-isonicotinyl hydrazide (iproniazid) to animals has been shown to produce a 2-to 3-fold increase in endogenous brain serotonin and to increase the amounts of serotonin appearing in brain following 5HTP. However, iproniazid has little effect on peripheral depots of serotonin or on the metabolism of serotonin or tyramine when they are administered parenterally. This is due to its inability to penetrate to the site of monoamine oxidase in intact cells.