不同胃大部切除术后大鼠残胃对亚硝基胍诱发胃癌的影响

Study of the effects of different types of gastrectomy on the carcinogenesis of gastric stump induced with N-methyl-N'-nitro-N-nitroguaidine in rats

对１２０只Ｗｉｓｔａｒ大鼠行３种胃大部切除术：ＢｉｌｌｒｏｔｈⅠ、Ⅱ式和ＰＡＦＰＧ式，并以假手术作对照组，均喂以致癌剂（ＭＮＮＧ）。观察胃粘膜电位差（ＰＤ）、还原型谷胱甘肽（ＧＳＨ）和胃粘膜病变情况。结果发现，ＢｉｌｌｒｏｔｈⅠ、Ⅱ式之ＰＤ和ＧＳＨ明显低于对照组，胃癌前病变则明显多于对照组，ＢｉｌｌｒｏｐｔｈⅡ式残胃癌发生率最高（４７．０％）；ＰＡＦＰＧ式则接近对照组。表明残胃癌前病变和癌变与胃手术改变胃内环境有关，其中十二指肠、空肠内容物向胃返流，以及胃粘膜屏障和胃粘膜抗氧化能力受损可能起着重要作用。

One hundred and twenty Wistar rats were operated on with pylorus and antroseromuscular preserving gastrectomy(PAFPG)and subtotal gastrectomy of Billroth Ⅰor Billroth Ⅱ type and gastric carcinoma was induced to the gastric stump with N-methyl-N'-nitro-N-nitroguaidine.The rats with sham operation severd as the control.Gastric transmucosal potential difference(PD)and mucosal content of reduced glutathione(GSH)were determined and the histopathological changes of the gastric mucosa studied.It was found that both PD and GSH were significantly lower after Billorth Ⅰand Ⅱ gastrectomies and significantly higher in the precancerous lesions of the stump than in the control.The incidence of gastric stump carcinoma was the highest(47%)in the BIllroth Ⅱ group among the 3 operated groups.There was no significant difference of PD,GSH and histopathologlcal findings between the PAFPG group and the control.Our findings suggest that the development of precancerous lesions and carcinoma in the gastric stump is possible to result from the alterations of the physiological environment after gastrectomy.Duodenogastric reflux,the injury of gastric mucosa barrier and the decrease of antioxidant ability of the gastric mucosa can be used to explain why gastric cancer occurs.