Effects of monoamine oxidase inhibitors on the borohydride stabilizable binding of serotonin and tryptamine in brain.

The in vivo and in vitro effects of various monoamine oxidase inhibitors (MAOI) on the borohydride stabilizable finding of serotonin (5-HT) or tryptamine in brain was investigated. A significant correlation between the extent of Mao inhibition and the amount of stabilized binding of the indolealkylamines was demonstrated. All hydrazine-type MAOI and harmine, a reversible nonhydrazine-type MAOI, employed in vitro, were shown to decrease the binding. beta-Phenylisopropylhydrazine apparently blocks the receptor carbonyl groups in the brain in vitro as well as in vivo.