CELLULAR PROLIFERATION AND DIFFERENTIATION IN RAT ATROPHIC GASTRIC-MUCOSA INDUCED BY N-METHYL-N'-NITRO-N-NITROSOGUANIDINE

It has been demonstrated that mucosal cell proliferation in atrophic g astritis is significantly accelerated, although the dynamics of the ce ll proliferation and differentiation have not been well characterized, We sequentially analyzed the markers of proliferation and differentia tion of rat atrophic gastritis induced by MNNG. Immunohistochemical st aining by anti-BrdU, anti-PCNA, and anti-PDGF-BB antibodies demonstrat ed that cell proliferation in atrophic gastritis was accelerated not o nly in the parenchymal tissue but also in the mesenchymal tissue. Expr ession of a gap junction protein (connexin 32), which is a marker for differentiation of epithelial cells, was reduced during the progressio n of atrophy. Some apoptotic cells were observed in the lower to middl e third of the atrophic mucosa, whereas apoptotic cells were rarely se en in normal mucosa, which suggests that apoptosis in these parts of t he mucosa may be related to the occurrence of mucosal atrophy.