Inhibition of sound-induced convulsions by metoprine in the audiogenic seizure susceptible rat.

Metoprine which increases brain histamine by blocking its methylation, was recently demonstrated to inhibit electrically induced tonic convulsions in rats. Its effect was now tested on audiogenic convulsions in genetically audiogenic seizure sensitive rats. Metoprine (20 mg/kg, i.p.) reduced the severity of seizures significantly 4 and 28 h after drug administration. Also the duration of convulsions was significantly decreased. These results agree with an involvement of histaminergic neurons in convulsive phenomena perhaps as a part of an anticonvulsive inhibitory transmitter system.