Indole Metabolism in the Malabsorption Syndrome

PREVIOUS studies have demonstrated that the excretion of the serotonin metabolite, 5-hydroxyindoleacetic acid, is elevated in patients with nontropical sprue.1 , 2 Other studies have shown that when a patient with nontropical sprue is placed on a gluten-free diet and remission occurs, excretion reverts to normal levels.3 When urinary extracts from a patient with nontropical sprue were subjected to paper chromatography for assay of 5-hydroxyindoleacetic acid large amounts of another indole compound were discovered. It was determined that this substance was indole-3-acetic acid, and the daily urinary excretion of this substance was in the order of 200 mg. daily — a marked . . .