Excretion of Homogentisic Acid After Oral Administration of Phenylalanine to Alcaptonuric Subjects

Abstract

Summary

Oral administration of 10 to 15 g daily of l(-)-phenylalanine to two alcaptonuric brothers resulted in a notable increase in the excretion of homogentisic acid in the urine, corresponding to about 70% of the amount theoretically obtained by complete conversion of the phenylalanine fed to homogentisic acid. The excretion of the extra homogentisic acid began promptly and was nearly complete within 12 hours after the phenylalanine was fed.