脑死亡状态对巴马小型猪胰腺及小肠组织中蛋白激酶-C的影响

Effects of brain death on protein kinase C expression in pancreatic and intestinal tissues of Ba-Ma mini pigs

目的:探讨脑死亡状态下胰腺及小肠组织中蛋白激酶C(protein kinase C,PKC)水平的变化.方法:巴马小型猪10只,随机平均分为脑死亡组及对照组.用颅内加压法建立脑死亡模型,脑死亡后6,12和24 h点活检部分胰腺和小肠组织行电镜观察,并用RT-PCR和免疫组化法检测PKC-αmRNA和蛋白的表达情况.结果:脑死亡组胰腺和小肠组织中PKC-αmRNA均表达,并随着脑死亡时间的增加表达亮度增高,而在对照组胰腺和小肠组织中PKC-αmRNA无表达.脑死亡组PKC-α蛋白在胰腺和小肠组织中的表达显著高于对照组,并且6、12、24 h间也有显著差异(0.6209±0.031 vs 0.381±0.038 vs 0.151±0.0108;P<0.05).对照组PKC-α蛋白在胰腺及小肠细胞胞质内表达,仅见少量阳性细胞.电镜下,脑死亡组胰腺及小肠组织形态学变化明显重于对照组.结论:脑死亡状态下胰腺及小肠组织中PKC-αmRNA和蛋白表达水平明显升高,这可能与脑死亡状态下胰腺及小肠的组织损伤有关.

AIM： To investigate the effects of brain death on the expression of protein kinase C （PKC） in the pancreatic and intestinal tissues of Ba-Ma mini pigs. METHODS： Ten Ba-Ma mini pigs were randomized into 2 groups： brain-dead group （group B, n = 5） and control group （group C, n = 5）. Intracranial pressure was increased to induced the brain-dead model. Pancreatic and intestinal tissues were sampled for electron microscopy at the 6^th, 12^th and 24^th hour after modeling. Reverse transcription-polymerase chain reaction and immunohistochemistry were used to detect the expression of PKC-（z both at mRNA and protein levels, respectively. RESULTS： PKC-α mRNA was expressed in both pancreatic and intestinal tissues and it was increased with brain-dead time. However, the expression of PKC-α mRNA was not found in the normal controls. The protein expression of PKC-α was significantly higher in pancreatic and intestinal tissues of group B than that of group C, and it was also significantly varied between different time points （0.151 ± 0.0108 vs 0.381 ± 0.038 vs 0.6209 ± 0.031; P〈0.05）. PKC-α protein expression was located in the cytoplasm of pancreatic and intestinal cells, and few positive cells were found. Electron microscopy showed that the pathological changes were more severe in group B. CONCLUSION： Brain death may lead to functional and morphological injury in pancreas and intestine and the up-regulation of PKC-α may play a role in this process.