Abstract
Following the ingestion of 10 g. of Dl-tryptophane, normal subjects excrete kynurenine, kynurenic acid and occasionally N-acetyl kynurenine. In pregnancy many additional metabolites, including 3-hydroxy-kynurenine, occur in the urine. The abnormal tryptophane metabolite excretion pattern in these women is strikingly similar to the one described in vit. Bg deficient rats. Administration of pyridoxine suppresses to a large degree the excretion of the abnormal substances.