摘要: This paper reviews some of the earlier experimental studies concerning role that tryptophan plays in enhancing tumorigenesis induced by selected chemical carcinogens. For many years, has been implicated carcinogenesis bladder. The evidence regarding tryptophan's effect on hepatic is conflicting; an reported investigators, but a reduction other workers. Some unique effects exerts upon liver are reviewed. Also, from our laboratory which we observed potentiating increased dietary induction gamma-glutamyltranspeptidase-positive foci when rats were fed choline-supplemented diet no potentiation was found choline-deficient for 10 weeks. results suggest promoting as measured livers exposed to diethylnitrosamine. possible significance these findings