Neuropharmacology of Tranylcypromine and Trifluoperazine

Tranylcypromine was compared to trifluoperazine in a number of pharmacological test procedures. Both compounds were effective in producing catalepsy, a selective blockade of the conditioned stimulus, and potentiation of hexobarbital-induced sleep. Unlike trifluoperazine, tranylcypromine was very effective as a tryptamine potentiator, a reflection of its activity as an in vivo inhibitor of the enzyme monoamine oxidase. Tranylcypromine was ineffective in producing any appreciable decrease in spontaneous motor activity at doses up to 20 mg/kg, whereas the DD50for trifluoperazine was 1.1 mg/kg.