Differential proliferative response of gastric mucosa during carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in susceptible ACI rats, resistant Buffalo rats, and their hybrid F1 cross.

摘要: The effect of A'-methyl-Ar'-nitro-/V-nitrosoguanidine(MNNG) on the proliferative characteristics pyloric epithelium was investigated in ACI and Buffalo rats their 1i rats, which are susceptible, resistant, respectively, to gastric Carcinogenesis by this chemical. After injection bromodeoxyuridine (BrdUrd), DNA synthesizing cells were stained immunohistochemically with antiBrdUrd antibody. average number range distribution labeled BrdUrd glands significantly larger than or F, after administration MNNG (83 MiA®/nil drinking water) for 2 16 weeks. In control given tap water weeks, there no significant difference these values three groups (Experiment 1). that [mefA>'/-3H]MNNG measured histoautoradiography, double both ImcfArM I|MNN /-3H]MNNGby gavage an 1 h, before sacrifice. (i.e.. replicating exposed MNNG) I-, rats. without (Exper iment 2). Cells |mefA>>/-3H]MNNG consid ered be potential establish mutations (cell population at risk MNNG-induced Carcinogenesis). Our results show that, treatment, size cell is susceptible resistant 1-,rats. Thus, differential responses mucosa may a key factor susceptibility Carcinogenesisbetween