Effects of pargyline and SKF-525A on brain N,N-dimethyltryptamine concentrations and hyperactivity in mice.

Mice pretreated with the monoamine oxidase inhibitor pargyline showed a dose-dependent increase in hyperactivity for up to 2 h following injections of N,N-dimethyltryptamine (DMT: 0.5-8.0 mg/kg). Hyperactivity was related to a linear increase in whole brain concentrations of DMT as measured by a new sensitive gas chromatographic assay. The duration of this behaviour paralleled the concentration of DMT in the brain from 15-120 min. However, at 15 min, there was no significant difference in brain DMT concentrations between mice receiving pargyline and those given distilled water at the two dose levels of DMT studied (2.0 and 8.0 mg/kg). Pre-treatment with the microsomal enzyme inhibitor SKF-525A, alone or in combination with pargyline, had no effect on the DMT-induced behaviour or on the brain levels of DMT.