[Tryptophan metabolism in vitiligo]

An activity of tryptophan pyrrolase was not observed in skin of healthy persons and of patients with vitiligo. Content of serotonin was similar in skin of normal persons and in skin of patients with normal pigmentation and in depigmented area. But content of serotonin in blood and excretion of anthranilic acid were decreased in the patients as compared with healthy persons. Excretion of kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, kynureninic, xanthurenic and 5-hydroxyindolyl acetic acids was increased in patients and this increase was more distinct after loading with 1-tryptophan. The data obtained suggest that kynurenine and serotonin pathways of tryptophan metabolism were intensified in vitiligo.