N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in experimental rat gastrocarcinogenesis: comparative sensibility to MNNG-carcinogenic action of the gland epithelium and the epithelium of experimental endophytic hyperplastic adenomatous structures.

The comparative sensibility of the stomach gland epithelium and the epithelium of experimental gastric adenomatous diverticuli to carcinogenic action of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined in experiments carried out in 107 rats; pathohistological techniques and electron-microscopic methods were applied. The epithelium of adenomatous diverticuli showed no signs of atypia or neoplasia in the course of MNNG-induced gastrocarcinogenesis. On the contrary, the epithelium of the gland cambial zone developed precancerous changes and adenocarcinomas. The formation of experimental diverticuli did not stimulate the development of rat stomach cancer.