Metabolism of 5-Hydroxyindole Compounds in Experimentally Produced Phenylketonuric Rats.

Abstract

Data have been presented confirming experimental production of phenylketonuria in rats. Supplementation of the diet with both phenylalanine and tyrosine resulted in a marked increase of phenylpyruvate excretion in urine and of phenylalanine level in plasma. Supplementation with 2.5% DL-phenylalanine alone showed a much less marked effect. The rise of phenylpyruvate coincided with a decrease of 5-hydroxyindole-acetic acid in the urine. Similarly, the increase of phenylalanine in the plasma coincided with a decrease of 5-hydroxytrypta-mine in the plasma. This indicates that the disturbance of 5-hydroxyindole metabolism in phenylketonuria is secondary to the increase in phenylalanine. The possible significance of these phenomena in the etiology of mental deficiency and phenylketonuria has been discussed.