Abstract
Present report includes the studies on the tryptophan metabolism in the experimentally induced riboflavin deficient rats, administered with pyridoxal phosphate, pyridoxine and TPNH with simultaneous subcutaneous injection of FMN, investigating the urinary excretion of anthranilic acid, kynurenine, xanthurenic acid and N-methylnicotinamide after an oral administration of 50mg of _L-tryptophan. A considerable amount of anthranilic acid, xanthurenic acid and a small amount of N-methylnicotinamide was excreted in riboflavin deficient rats more than those of healthy control group, while kynurenine was almost unchanged. By the administration of FMN alone, the considerable decrease of the excretion of anthranilic acid and xanthurenic acid, and increase of the excretion of N-methylnicotinamide was observed, while kynurenine was unchanged. When pyridoxal phosphate or pyridoxine was given with FMN, xanthurenic acid excretion further decreased and N-methylnicotinamide increased more than in the simple administration of FMN, while anthranilic acid and kynurenine were unchanged. As for TPNH induction, no considerable difference was found except a slight decrease of kynurenine. Furthermore, the excretion of xanthurenic acid decreased in cases of the simple application of pyridoxal-phosphate and pyridoxine. In the control group, no appreciable difference was perceived.
