[Relationship between tryptophan metabolism and the state of melaninogensis]

In studying the excretion of tryptophan and the activity of tryptophan pyrrholase of the liver in black and albino rabbits it was revealed that the kinurenine, kinurenic and xanthurenic acids, 3-hydroxykinurenin, anthranylic acid and 5-hydroxyindolylactic acid levels in the urine collected before the L-tryptophane loading differed in these animals. No 3-hydroxyanthranylic acid was found in the initial urine of these rabbits. A sharp intensification of excretion of all the tryptophane metabolites studied followed the administration of L-tryptophane to albino rabbits, and a harper elevation of kinurenic and xanthurenic acid excretion--to black rabbits. In comparison with black rabbits, the tryptophan pyrrholase of the liver of albino rabbits reached to the L-tryptophan administration more intensively.