ENHANCEMENT BY MONOCHLORAMINE OF THE DEVELOPMENT OF GASTRIC CANCERS IN RATS - A POSSIBLE MECHANISM OF HELICOBACTER-PYLORI-ASSOCIATED GASTRIC CARCINOGENESIS

The effects of cytotoxic monochloramine on the development of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine were investiga ted in Wistar rats. After oral administration of drinking water contai ning the carcinogen and regular chow pellets for 25 weeks, rats receiv ed regular chow pellets or chow pellets containing 20% ammonium acetat e, and normal tap water or water containing 30 mM sodium hypochlorite, with or without s.c. injection of taurine, until the end of the exper iment in week 52. Treatment with both ammonium acetate and sodium hypo chlorite significantly increased the incidence of gastric cancers in w eek 52, while the concomitant use of taurine with ammonium acetate and sodium hypochlorite significantly attenuated the enhanced gastric car cinogenesis. Spectrophotometric examinations revealed that taurine sca venged monochloramine. These findings suggest that Helicobacter pylori -associated gastric carcinogenesis may be mediated by monochloramine.