十二指肠胃反流对大鼠胃黏膜细胞增殖与凋亡及相关基因表达的影响

目的　探讨十二指肠胃反流 (DGR)引起大鼠胃黏膜损伤及癌变的发病机制。方法　健康成年雄性SD大鼠 (75只 )随机分为两组 :①DGR模型组 (5 5只 ) ,根据手术造模方式及反流量大小分为全反流组与部分反流组。②假手术对照组 (2 0只 )。采用pH监测仪测定胃液 pH ,用酶法测定胃液胆汁酸 (TBA) ,确定DGR模型成功。进行为期 3个月和 9个月胃黏膜损伤的动态观察。采用免疫组化方法分析不同病变胃黏膜组织PCNA、Bcl 2蛋白的表达。采用TUNEL技术观察胃黏膜细胞凋亡情况。结果　DGR模型大鼠胃液pH及TBA明显升高 (P <0 .0 1) ,证明DGR模型成功。模型大鼠病理改变出现浅表性胃炎→萎缩性胃炎→异型增生的动态演变过程。正常胃黏膜→浅表性胃炎→萎缩性胃炎 ,增殖指数 (PI)、凋亡指数 (AI)均呈上升趋势 (P <0 .0 5 ) ,PI与AI呈正相关 (r=0 .6 8,0 .71)。从萎缩性胃炎→异型增生 ,PI仍显著增加 ,在异型增生时AI突然下降 ,AI/PI也明显降低 (P <0 .0 1) ,AI与PI呈负相关 (r=- 0 .5 7)。萎缩性胃炎及异型增生时PCNA、Bcl 2蛋白表达显著高于假手术对照组及浅表性胃炎组 (P <0 .0 5 ) ,萎缩性胃炎与异型增生之间PCNA、Bcl 2表达差异无显著性 (P >0 .0 5 )。结论　细胞增殖与凋亡调节紊乱可能是十二指肠反流液造成胃黏膜损伤?

Experimental study on the relationship between cell proliferation and apoptosis and the expression of the related gene in rats with duodenogastric reflux

Objective To investigate the pathogenesis of gastric mucosa injury and cell canceration caused by duodenogastric reflux (DGR). Methods Adult male SD rats (75) were randomly divided into two groups. The model group with DGR (55) was classified into full reflux group and part reflux group according to its degree of reflux. In control group there were sham operation rats (20). Rat models were confirmed to be successful by monitoring pH and measuring total bile acid (TBA) in gastric juice. After gastrojejunostomy for 3 months and 9 months, the pathological character of gastric mucosa in model rats was CSG, CAG and Dys using light microscope. ABC immunohistochemical staining was used to detect the expression of PCNA and Bcl-2 proteins. Cell apoptosis in gastric mucosa was determined by TUNEL technique. Results The pH and TBA of gastric juice in model rats were significantly higher than those in control rats (P<0.01). These results demonstrated that rat models with DGR were successful. The pathology of gastric mucosa in rat models represented CSG, CAG and Dys. The proliferation index (PI) and apoptosis index (AI) in normal gastric mucosa, CSG and CAG were increased gradually (P< 0.05). PI and AI in CSG and CAG were positively correlated (r= 0.68, 0.71). From CAG to Dys, PI was still increased, but AI suddenly decreased in Dys, AI/PI ratio decreased, too (P< 0.01). AI and PI were negatively correlated(r= -0.57). The positive expression rates of PCNA and Bcl-2 in CAG and Dys were significant higher than those in CSG and control group (P< 0.05). There was no significant difference between CAG and Dys (P> 0.05). Conclusion Disorders in cell proliferation and apoptosis are one of major pathogenesis of gastric mucosa injury and cell canceration with DGR. The overexpression of PCNA, Bcl-2 gene proteins in CAG and Dys may play a key role in the development of gastric cancer.