Tryptophan Pyrrolase Activity in Rats Subjected to Electic Convulsions

Xanthurenic aciduria following an oral dose of tryptophan was frequently seen in children with convulsive disorders. In order to elucidate the mechanism through which xanthurenic aciduria developed in these children, a study of liver enzymes related to tryptophan metabolism was done on rats with electric convul-sions. The results showed that, in rats with the electric convulsion, there was a marked elevation of tryptophan pyrrolase activity but no remarkable change in activities of both kynureninase and kynurenine transaminase of the liver and an increase in urinary excretion of xanthurenic acid following an oral dose of tryptophan. From these results, it was suggested that xanthurenic aciduria in children with convulsive disorders was due to an enhanced yielding of xanthurenic acid as a result of increased activity of try ptophan pyrrolase induced by convulsions.