Pozharisski K M, Klimashevski V F, Gushchin V A
Exp Pathol. 1982;21(3):165-79. doi: 10.1016/s0232-1513(82)80067-4.
A stage-by-stage study of disturbances in enterocyte proliferation in the ileum and descending colon in the course of tumour induction by treatment with 1,2-dimethylhydrazine was performed. Even at early stages, an expansion of the zone of epithelial cell proliferation in the crypts and migration of dividing cells as far as to the crypt mouth, which is a manifestation of enterocyte differentiation disturbances, were observed. Enterocytes of the crypts chiefly proliferated through a short cycle, the mean duration of which was slightly greater than in normal intestinal tissue. The reduced cell loss in the epithelium and resultant disturbances of its steady state led to the accumulation of great numbers of atypical cells in the superficial layers of the crypts and formation of carcinomas in situ in the descending colon. The microscopically unaltered sections of the mucosa, prior to development of overt neoplastic changes carcinomas in situ, superficial cancers and small-size adenocarcinomas revealed a simplified structure of enterocyte population, as compared with normal epithelium. As tumours progressed, the heterogeneity of its component cell subpopulations increased, and several subpopulations, differing in mean duration of the mitotic cycle, were formed. Pathologic mitoses made up a greater portion (50-60 per cent) of the dividing cells of the descending colon, as compared with ordinary 4 per cent at all stages of experimental tumour induction.
对用1,2 - 二甲基肼诱导肿瘤过程中回肠和降结肠肠上皮细胞增殖紊乱进行了分阶段研究。即使在早期阶段，也观察到隐窝上皮细胞增殖区扩大以及分裂细胞迁移至隐窝口，这是肠上皮细胞分化紊乱的表现。隐窝的肠上皮细胞主要通过短周期增殖，其平均持续时间略长于正常肠道组织。上皮细胞损失减少及其稳态紊乱导致大量非典型细胞在隐窝表层积聚，并在降结肠形成原位癌。在明显的肿瘤性变化（原位癌、浅表癌和小腺癌）出现之前，显微镜下黏膜未改变的切片显示，与正常上皮相比，肠上皮细胞群体结构简化。随着肿瘤进展，其组成细胞亚群的异质性增加，并形成了几个有丝分裂周期平均持续时间不同的亚群。与实验性肿瘤诱导各阶段通常的4%相比，病理性有丝分裂在降结肠分裂细胞中所占比例更大（50 - 60%）。
