大鼠实验性腺胃粘膜癌变过程的组化观察

Histological and histochemical observation on N-methyl-N-nitro-N-nitrosoguanidine and ranitidine-induced gastric glandular mucosal lesions in rats

对甲基硝基亚硝基胍（ＭＮＮＧ）和雷尼替丁联合诱发的大鼠腺胃粘膜癌变过程作动态组织学及粘液组化观察，发现：（１）肠上皮化生首先出现于腺颈部，之后向粘膜表面或底部延伸，支持肠化起始于腺颈部多潜能干细胞的观点；（２）异型增生有向粘膜表面和底部增殖两种不同的发生方式；（３）腺体囊状扩张及异型囊可能是一种胃癌前期变化；（４）实验性胃癌的组织发生至少有两种方式：异型增生→胃癌和肠上皮化生→异型增生→胃癌；（５）粘液分泌的变化可能是胃粘膜癌变早期的特征性表现之一。

The sequential lesions of gastric glandular mucosa induced with N-methyl-N-nitro-N-nitrosoguanidine(NNNG)and ranitidien(R) in rats were observed histologically and mucohistochemically.It was found that intestinal metaplasia(IM) was first found in the glandular neck before the 12th week after the administration of the drugs.In the 14th to l6th week,IM extended to the surface or bottom of the mucous membrane.In the 18th week, IM was mainly confined to the lower third of the mucosa of different part of the stomach.Dysplasia was found onthe surface or bottom of the mucosa and developed from IM or unchanged mucosa directly. Focal IM was the first pathological change recognized under optical microscopy and then dysplassia and gastric carcinoma subsequently.Cystic dilatation or dysplastic cysts were found in the 20th to 32nd week.The distribution pattern of the mucous substance in the epithelium was altered in IM.dysplasia, cystic dilatation and gastric carcinoma. It was concluded the basis of the findings as follows:(1)IM can arise from the proliferative zone of cells in the glandular neck and then extends to the surface or bottom of gastric mucosa.(2)Dysplasia can develop in 2 ways:The first is to develop in the proliferative zone and extend to the surface,during which, the superficial cells are replaced by atypical calls one after another,and the second is to shift the proliferative zone away from the lumen toward the base.(3)The carcinogenesis in the stomach manifests itself in 2 patterns, which are from dysplasia to gastric carcinoma directly or from IM through dysplasia to gastric carcinoma.(4)Cystic dilatation and dysplastic cysts in the gastric mucosa may be considered as precancerous lesions. (5) The changes of the distribution of mucous substances in the gastric mucosa may be an early sign of carcingeneis.