The Facilitative Action of Reserpine on Metrazol Convulsions When Modified by Iproniazid*

The effects of reserpine, iproniazid, and their combination on the convulsive threshold, facilitative action, ana seizure pattern of metrazol-treated mice was investigated. The effect of reserpine on metrazol convulsions is a marked decrease in convulsive dose which is accompanied by a reduced seizure latency time in the convulsive pattern with an increasing facilitative action. Iproniazid was found to increase the convulsive dose and lengthen the latency interval. Prior treatment with iproniazid before reserpine reversed the depressive state produced by the latter agent to that of stimulation. This was accompanied by an increased anticonvulsant effect, longer latency interval, and absence of a facilitative action. Treatment with iproniazid after reserpine failed to elicit these effects. These results are compatible with the hypothesis that iproniazid and reserpine produce their effect through a biochemical change, the former by monoamine oxidase inhibition and the latter by release of norepinephrine and other amines from their storage sites in the central nervous system.