Abnormal tryptophan metabolism in a family with a history of bladder cancer.
Tryptophan metabolism was studied in a family in which a sister and brother had bladder cancer. Urinary tryptophan metabolites after administration of 2 g L-tryptophan were measured in 4 sisters and 1 brother, all free of disease when studied. One sister with and 2 without histories of bladder cancer had significantly elevated levels of kynurenine, acetylkynurenine, and 3-hydroxykynurenine. Administration of 100 mg pyridoxine hydrochloride returned the tryptophan metabolism to normal in these 3 individuals. One brother with a 1 sister without bladder cancer had normal metabolism. A repeat study 2 years later confirmed the abnormal metabolism in the 3 sisters. Two sisters with abnormal tryptophan metabolism were given 200 mg L-kynurenine sulfate orally to bypass the effects of tryptophan oxygenase activity. Both excreted elevated levels of kynurenine and 1 excreted elevated levels of 3-hydroxykynurenine.
D000368:Aged; D005260:Female; D006801:Humans; D007737:Kynurenine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000652:urine; D008297:Male; D008661:Metabolism, Inborn Errors / Q000235:genetics; D008875:Middle Aged; D011736:Pyridoxine / Q000494:pharmacology; D014364:Tryptophan / Q000378:metabolism*; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism
C005045:3-hydroxykynurenine; D007737:Kynurenine; D014364:Tryptophan; D011736:Pyridoxine