应激性溃疡时大鼠胃壁细胞功能及超微结构的动态变化

Dynamic changes of the function and ultrastructure of gastric parietal cells under stress ulcer in rats

目的 :探讨应激条件下大鼠胃壁细胞泌酸功能和超微结构的动态变化及与急性胃粘膜损伤之间的关系。方法 :将 32只雄性SD大鼠随机分成 4组 ,即对照组、水浸束缚应激 1,2、4h组。检测各组胃液pH值、胃粘膜溃疡指数 (UI) ,并取腺胃区粘膜制作透射电镜标本 ,观察壁细胞超微结构变化。结果 :应激条件下大鼠胃泌酸多于对照组 ,随应激时间延长胃液pH值明显低于对照组 (P <0 0 1) ;UI随应激时间延长明显增加 (P <0 0 1) ,与pH值之间呈明显负相关 (r=- 0 9987,P <0 0 1) ;电镜下见对照组壁细胞呈静息状态 ,而应激 1、2、4h组壁细胞呈现不同的激活状态 ,且以 4h为明显 ,壁细胞内线粒体丰富 ,分泌小管密集 ,囊管泡减少或消失 ,呈明显泌酸活跃状态。结论 :水浸束缚应激可引起大鼠胃酸分泌增加 ,这与壁细胞超微结构改变相一致 ,并与胃粘膜损伤程度有明显相关性。提示胃酸在应激性溃疡的发生发展过程中具有重要意义。

AIM: To evaluate the dynamic changes of the function and ultrastructure of gastric parietal cells under stress and their relation with acute gastric mucosal lesions. METHODS: Thirty-two male SD rats were randomly divided into four groups, which were control group and 1,2,4 h groups under water restraint stress (WRS). The gastric fluid pH value and gastric mucosal ulcer index(UI) were measured. The ultrastructural changes of parietal cells were observed by transmission electronic microscopy (TEM). RESULTS: The study demonstrated that gastric acid secretion increased and gastric fluid pH value decreased gradually and significantly under WRS compared with control group( P <0.01), and UI also increased significantly( P <0.01). Moreover, there was a negative correlation between UI and pH value( r =-0.9987, P <0.01). Parietal cells were in a resting state in control group, but became active in stress 1,2,4 h groups, and especially in stress 4 h group where plenty of mitochromosomes and secreting cysts were observed under the TEM. CONCLUSIONS: The results indicate that WRS may induce acid secretion of parietal cells in accordance with their ultrastructural changes, and the changes of parietal cells are correlated with the degree of the gastric mucosal lesions. These results suggest that gastric acid play an important role in the development of stress ulcer.