Effect of Phenylalanine Metabolites on Urinary Excretion of Indole-3-acetic Acid and 5-Hydroxyindole-3-acetic Acid in Man

Abstract

1) Oral administration of phenylpyruvic acid, phenylacetic acid, and o-hydroxyphenylacetic acid to human subjects resulted in increase in urinary excretion of indoleacetic acid. A smaller increase in excretion of 5-hydroxyindoleacetic acid followed administration of phenyrpyruvic acid and o-hydroxyphenylacetic acid. 2) o-Hydroxyphenylacetic acid was demonstrated to be more effective than either phenylpyruvic acid or phenylacetic acid in increasing excretion of indoleacetic acid. 3) The relation of these findings to inhibition of tryptophan decarboxylase and 5-hydroxytryptophan decarboxylase is discussed. © 1960, SAGE Publications. All rights reserved.