[Action site of bisphenol A as metabolic disruptor lies in the tryptophan-nicotinamide conversion pathway].

We have reported that the administration of bisphenol A to rats reduces the conversion ratio of tryptophan to nicotinamide. In the present paper, we show that bisphenol A, a monomer of polycarbonate plastics, inhibits the enzyme activity of kynurenine 3-hydroxylase. Namely, the conversion ratio of tryptophan to nicotinamide is reduced through the inhibition of kynurenine 3-hydroxylase activity by bisphenol A.