Effect of tryptophan and nicotinamide loads on urinary excretion of RNA metabolites by bladder cancer patients.
In a comparative study of tryptophan metabolism and urinary excretion of nucleic acid derivatives (including beta-aminoisobutyric acid, 7-methylguanine, pseudouridine, and urate) in 12 male bladder cancer patients, the excretion of pseudouridine and 7-methylguanine decreased significantly after an oral dose of 2 g L-tryptophan. A similar decrease occurred after an oral nicotinamide load of 50 mg four times a day, which indicated a possible common mode of action of tryptophan and nicotinamide. No definite resolution could be made as to the causal mechanism for the observed descrase in RNA turnover.
D000621:Aminoisobutyric Acids / Q000652:urine; D006147:Guanine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008297:Male; D009536:Niacinamide / Q000378:metabolism / Q000494:pharmacology*; D011560:Pseudouridine / Q000652:urine; D012334:RNA, Neoplasm / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism / Q000494:pharmacology*; D014527:Uric Acid / Q000652:urine; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000652:urine*
D000621:Aminoisobutyric Acids; D012334:RNA, Neoplasm; D011560:Pseudouridine; D009536:Niacinamide; D014527:Uric Acid; D006147:Guanine; D014364:Tryptophan