Effects of tranylcypromine andl-cysteine on plasma amino acids in controls and schizophrenic patients

Abstract

The effect of tranylcypromine and tranylcypromine plus cysteine loading on plasma amino acids of normal controls and schizophrenic patients was investigated. The study consisted of a control period, tranylcypromine loading, a tranylcypromine plus l-cysteine period, and a postmedication stage. The tranylcypromine loading increased the total amino acid in all normal controls except one and also in the two schizophrenic patients. The administration of l-cysteine with tranylcypromine was characterized by lower plasma amino acid levels for the seven subjects who had elevated amino acid concentrations during the tranylcypromine period. The normal control who showed lowered amino acid levels with tranylcypromine exhibited an increase when l-cysteine was given. The amino acid values were near baseline levels at the end of the postmedication period.