Possible production of hydroxyl free radical in the gastric legion of nitroso carcinogen-administrated rats

摘要

We have examined the mechanism of 1-metyl-3-nitro-l-nitrosoguanidine(MNNG)-induced gastric cancer with respect to the production of hydroxyl free radical (OH{sup left}·). In this work we showed that OH{sup left}· was produced with 1-methyl-3-nitroguanidine (MNG) by the nucleophilic attack of H{sub}2O{sub}2 derived from the XO system on the nitroso group of MNNG via the formation of the intermediate peroxynitric acid (ONOOH) which splits into hydroxyl free radical (OH{sup left}·) and nitrogen dioxide using ESR spin trapping technique, suggesting that the administration of MNNG to the gastric legion with the high XO activity results in the OH{sup left}· production.