[Enhancement of the convulsant action of strychnine following administration of kynurenines into the cerebral ventricles of frogs].

In frogs (Rana temporaria) injection of L-kynurenine, quinolinic, nicotinic and picolinic acids (10 microgram) into brain ventricles potentiated the stimulant ad convulsant effects of a subthreshold dose of strychnine. Xanthurenic and anthranilic acids were ineffective. At a dose of 100 micrograms picolinic acid produced seizures in 25% of animals, quinolinic acid and L-kynurenine motor excitement in all animals, and the action of nicotinic acid was shown by severe muscle hypotonus. The doses lower than 100 g proved inactive.