Nitrate, nitrite and volatile N-nitroso compounds in the urine of Schistosoma haematobium and Schistosoma mansoni infected patients

• Published in: Carcinogenesis (New York) 1994-04, Vol.15 (4), p.619-625
• Main Authors: Mostafa, M.H., Helmi, S., Badawi, A.F., Tricker, A.R., Spiegelhalder, B., Preussmann, R.
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Carcinogenesis, carcinogens and anticarcinogens; Egypt; Foods and miscellaneous; Humans; Male; Medical sciences; Middle Aged; Nitrates - urine; Nitrites - urine; Nitroso Compounds - urine; Saliva - metabolism; Schistosoma; Schistosomiasis haematobia - urine; Schistosomiasis mansoni - urine; Tumors
• ISSN: 0143-3334; 1460-2180
• DOI: 10.1093/carcin/15.4.619

The present study presents, for the first time, the amounts of nitrate, nitrite and volatile N-nitroso compounds in saliva and urine samples of Schistosoma haematobium and Schistosoma mansoni infected patients. Mid-morning saliva and 24 h urine samples were collected from male patients infected with S.haematobium (n = 129 saliva and 79 urine samples) and S.mansoni (n = 64 saliva and 65 urine samples) and in a comparative control group of healthy individuals (n = 27) from the Nile Delta region of Egypt. Saliva samples were analyzed for the presence of nitrate and nitrite; while urine samples were analyzed for the presence of nitrate, nitrite and volatile N-nitroso compounds. In the control group, N-nitroso-dimethylamine (NDMA) was detected at concentrations (mean ± SD) of 0.27 ± 0.47 μg/day. N-Nitrosopyrrolidine (NPIP; 0.6 μg/day) and N-nitrosopyrrolidine (NPYR; 0.4 μg/day) were also present in one sample. S.mansoni infected subjects showed significantly (P < 0.001) higher levels of 2.9 ± 2.9 μg/day NDMA and a higher frequency of NPIP (in 40/65 samples; 0.4 ± 0.3 μg/day) and NPYR occurrence (in 59/65 samples; 0.9 ± 0.9 μg/day). Significant further increases in the excretion of volatile N-nitroso compounds were found in S.haematobium-infected patients with mean daily excretion of 19.2 ± 21 μg/day NDMA (in all samples; P < 0.001), 1.6 ± 2.3 μg/day NPIP (in 56/79 samples; P < 0.001) and 1.3 ± 1.9 μg/day NPYR (in 58/79 samples; P < 0.1). The differences either in salivary nitrite/nitrate or in urinary nitrite between the three distinct groups were not significant. However, the urinary excretion of nitrate was elevated from 139 ± 82mg/day in the control group to 249 ± 126 mg/day in S.mansoni infected patients (P < 0.001) and to 174 ± 176 mg/day in S.haematobium infected subjects (P < 0.005 in comparison to S.mansoni infected group). These results suggest a possible role of N-nitroso compounds in the etiology of schistosome-associated bladder cancer and imply a partial participation of S.mansoni in the multistage process of urinary schistosomiasis-associated bladder carcinogenesis.