title: Urinary excretion of nitrate, nitrite and N-nitroso compounds in Schistosomiasis and bilharzia bladder cancer patients.
abstract: Saliva and 24-h urine samples were collected from male Schistosomiasis (bilharzia) patients with S. haematobium infection and possible concurrent S. mansoni infection without diagnosed bladder cancer (n = 27), bilharzia patients with diagnosed bladder cancer (n = 23) as well as a comparative control group (n = 27) of healthy Egyptian volunteers with no current bilharzia infection and/or bacterial urinary tract infections from the Nile Delta area of Egypt. Saliva samples were analysed for the presence of nitrate and nitrite; urine samples were analysed for the presence of nitrate, nitrite, volatile and non-volatile N-nitroso compounds. Bilharzia patients prior to, and after, diagnosed bladder cancer regularly excreted free nitrite as well as volatile nitrosamines (N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosopiperidine and N-nitrosopyrrolidine) in addition to which elevated concentrations of non-volatile N-nitrosamino acids (N-nitrosoproline, N-nitrososarcosine, N-nitrosothiazolidine-4-carboxylic acid and its 2-methyl derivative) were also present. Total urinary excretion of volatile N-nitroso compounds (0.32 +/- 0.64 micrograms/day; mean +/- SD) and non-volatile N-nitroso compounds (31.20 +/- 22.07 micrograms/day) was observed in the Egyptian control group. Significantly higher concentrations were found in bilharzia patients: 3.47 +/- 6.42 (P less than 0.05) and 62.91 +/- 21.96 (P less than 0.05); as well as in bilharzia patients with diagnosed bladder cancer: 1.71 +/- 1.96 (P less than 0.02) and 44.94 +/- 7.31 respectively. Free nitrite was found in the urine of two volunteers in the Egyptian control group (1.7 and 3.0 micrograms/day), urinary nitrite was significantly increased in bilharzia patients (5.18 +/- 9.11 micrograms/day, P less than 0.02) and in bladder cancer patients (1.75 +/- 2.81 micrograms/day, P less than 0.05). Nitrate concentrations were elevated from 139.3 +/- 82.2 in the control group to 143.6 +/- 136.3 and 175 +/- 190 in the bilharzia and bladder cancer groups respectively. These results indicate that significant in vivo formation of nitrite and volatile N-nitroso compounds occurs in the urinary bladder of bilharzia patients and this may be an oetiological factor in the induction of bilharzial bladder cancer associated with S. haematobium infection.
authors.affiliation: Institute of Toxicology and Chemotherapy, German Cancer Research Center, Heidelberg, FRG.
authors.forename: A R
authors.initials: AR
authors.lastname: Tricker
authors.forename: M H
authors.initials: MH
authors.lastname: Mostafa
authors.forename: B
authors.initials: B
authors.lastname: Spiegelhalder
authors.forename: R
authors.initials: R
authors.lastname: Preussmann
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000652:urine*; D009573:Nitrites / Q000652:urine*; D009603:Nitroso Compounds / Q000032:analysis / Q000652:urine*; D012463:Saliva / Q000032:analysis; D012552:Schistosomiasis / Q000150:complications / Q000652:urine*; D001749:Urinary Bladder Neoplasms / Q000209:etiology / Q000652:urine*; D014835:Volatilization
chemical_list: D009566:Nitrates; D009573:Nitrites; D009603:Nitroso Compounds