Induction of Experimental Atrophic Gastritis by N-Methyl-N'-Nitro-N-Nitrosoguanidine or Taurocholic Acid in Donryu Rats

The morphology of the rat (Donryu) gastric mucosa was examined by light microscopy after administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or taurocholic acid (TCA), a component of bile acids. MNNG was given to rats ad libitum from light-sealed bottles for 5 months and deionized water was given freely for 6 months thereafter. TCA was administered to rats freely for 11 months. Deionized water was given to rats as control (non-treated rats). Rats treated with MNNG or TCA and control rats were killed at 11 months after the beginning of the experiment. Using 3 micron tissue samples taken from the area of the gastric mucosa designated before the experiment, hematoxylin and eosin and azan stain were made for histopathological evaluation and fibrosis. Marked atrophic changes, such as reduction in the number of parietal cells, shortened mucosa! length, inflammaotry cell infiltration, and proliferation of fibrosis, were present in the gastric mucosa of rats treated with MNNG as well as TCA. These findings were typical for atrophic gastritis. Such atrophic changes were slight in the gastric mucosa of the control rats. The frequency of tumourous lesions was very low in MNNG-treated rats. We have concluded on the basis of the present data that MNNG as well as TCA can induce atrophic gastritis in Donryu rats