N-nitrosamine generation by urinary tract infections in spine injured patients.

Urine was collected from 33 patients resident at the Welsh Spinal Injuries Unit and analysed for volatile N-nitrosamines by gas chromatography. N-nitrosodime-thylamine, N-nitrosopiperidine or N-nitrosopyrrolidine was detected in 32 of the samples. Thirty-one of the samples were infected by one or more microbial species. Nitrate and N-nitrosamines were not found in the sterile urines of a group of 10 control individuals exposed to the same dietary and environmental influences as the spinal patients. Although N-nitrosamines were found in some of the catheter drainage system products, they did not elute into urine on 24-h exposure. In addition, 6 of the nitrosamine-containing urines had no contact with drainage systems as they were collected from spinal patients who were capable of independent voiding. It was concluded that the nitrosamines detected in the urines arose from the bacterial nitrosation of urinary amines. These results support the hypothesis that chronic urinary tract infection may have a role in the aetiology of bladder cancer in spine injured patients.