D-amphetamine and DL-alpha-N-methyltryptamine eliminate the irreversible inhibition of mitochondrial monoamine oxidase, caused by clorgyline. The specific action on the tyramine oxidation.

A new hitherto unknown important property of D-amphetamine (but not L-isomer) and DL-alpha-N-methyltryptamine was discovered. These substances decrease the irreversible inhibition by clorgyline of tyramine deamination without affecting a sharply expressed inhibitory effect of clorgyline on serotonin oxidation. As a result of such a directed increase of selectivity, clorgyline became a still more highly specific inhibitor of serotonin oxidation without affecting, even at relatively high concentrations, tyramine deamination.