Effect of tryptophan metabolites on activity of the epileptogenic focus in the frog hippocampus.

In frogs with the epileptogenic foci made by injection of penicilline (1000 U in 0.4 mcl) in the primordial hippocampus it was shown that preliminary administration of two kynurenines quinolinic acid (0,1 microgram) and d,l-kynurenine (1 microgram), in the foci region, and their injection in the functioning epileptogenic foci led to a strong increase of the interictal epileptiform discharges and of the electrographic correlates of fits on the EEG. Anthranilic acid (0.1, 1.0 and 5.0 micrograms) did not influence the activity of epileptogenic foci. Serotonin (1 microgram) and 5-methoxytryptamine (1 microgram) essentially decreased it. Provocating effect of kynurenines on neurons in epileptogenic foci is supposed to play a certain role in pathogenesis of epilepsy.