The role of kynurenines in diabetes mellitus.

Although different forms of diabetes are known to exist, there are a number of factors which occur in these states all of which would contribute to an increase in the synthesis of the kynurenine metabolites of tryptophan, xanthurenic acid in particular. Conditions giving rise to increased kynurenine metabolism include pregnancy, oral contraceptives, emotional and metabolic stress. We propose a mechanism by which kynurenines act to reduce the concentration of active insulin in plasma and thus give rise to a diabetic state.