失血性休克大鼠肠上皮细胞线粒体DNA腺苷三磷酸酶6,8基因表达及线粒体功能的改变

目的　探讨失血性休克大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达及线粒体功能的改变 ,为阐述休克肠道靶学说和线粒体能量代谢提供分子生物学基础。　方法　 2 4只Wistar大鼠随机分为休克前组和休克 1,2 ,3,4 ,5h组。采用RT -PCR方法观察线粒体ATPase 6 ,8mRNA量的改变。用透射电镜观察、生物体视学测量线粒体形态 ,用Clark氧电极测线粒体呼吸功能。　结果　失血性休克 1,2h ,ATPase 6 ,8基因表达增强 ,以后渐减弱 ,至休克 5h表达最低 ,ATPase 6 ,8基因表达分别降为正常的 6 9.3%和 78.4 % (P <0 .0 1和P <0 .0 5 )。失血性休克 2h和5h ,线粒体平均截面积、长径、面密度、体密度均显著增加 (P <0 .0 1) ,休克 5h时分别为休克前的2 .0 ,1.4 5 ,1.4 7,2 .2 2倍。休克 5h ,线粒体比表面和数密度分别下降 32 %和 2 4 % (P <0 .0 1和P <0 .0 5 ) ,嵴和基质破坏明显。失血性休克后肠上皮细胞线粒体呼吸控制率和氧化磷酸化效率比休克前显著降低 (P <0 .0 1)。　结论　失血性休克时大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达下调 ,线粒体呼吸功能出现障碍 ,线粒体超微结构发生了改变

Expression changes of mitochondrial DNA adenosinetriphosphatase 6,8 genes and mitochondrial function changes in epithelial cells of small intestine in hemorrhagic shock rats

Objective To study expression changes of mitochondrial DNA ATPase 6,8 genes (ATPase 6,8 genes) and mitochondrial function changes in small intestinal epithelia in hemorrhagic shock rats, which may provide molecular biological basis for intestinal target theory and mitochondrial energy metabolism during hemorrhagic shock. Methods A total of 24 Wistar rats were randomly divided into six groups, ie, pre shock group, shock for 1, 2, 3, 4 and 5 hours groups (shock 1,shock 2, shock 3, shock 4 and shock 5 groups respectively). The expressions of mitochondrial ATPase 6,8 genes were observed by means of RT PCR. The mitochondrial parameters of morphometry were examined by electron microscopy and biogenetics stereology, and respiratory function by Clark oxygen electrode. Results The expressions of ATPase 6,8 genes increased in epithelia after hemorrhagic shock for one and two hours and decreased gradually. In the shock 5 group, the expressions reached the lowest, ie, 69.3% and 78.4% of the normal expressions respectively ( P <0.01 and P <0.05). In the shock 2 and 5 groups, mean transaction area, diameter, surface density and volume density of mitochondria increased significantly, which were 2.0, 1.45, 1.47 and 2.22 respectively more than those in the pre shock group ( P <0.01). Meanwhile, specific surface and numeral density of the mitochondria decreased by 32% and 24% respectively ( P <0.01 and P <0.05 respectively). The mitochondrial crist and matrix were destroyed seriously and its respiratory control ratio and efficiency of oxidative phosphorylation dropped markedly compared with that in the pre shock group ( P <0.01). Conclusions Expressions of ATPase 6,8 genes in the small intestinal epithelia decrease at hemorrhagic shock. In the meantime, the mitochondrial respiratory function is affected and there occur changes of the mitochondrial ultrastructure in rats after hemorrhagic shock.