摘要目的 观察腹腔注射胰激肽原酶(PKK)对1型糖尿病小鼠周围神经病变的保护作用.方法 选用Akita小鼠为1型糖尿病模型,每周检测小鼠血糖和体重,在出现高血糖后8周,开始每天药物干预,共持续8周.分组:野生型正常对照组小鼠每日接受生理盐水注射(WT组,n=12)、糖尿病对照组每日接受生理盐水注射(NS组,n=6)、糖尿病治疗组每日接受PKK治疗(PKK组,n=6).药物干预结束后,取小鼠后肢特异性投射的脊髓背根神经节(DRGs),应用透射电镜观察DRGs神经元的超微结构;应用定量实时聚合酶链反应(Q-PCR)检测3组DRGs中葡萄糖-6-磷酸脱氢酶(G6PD)的mRNA表达.弗里德曼方差分析用于多样本间的比较分析.结果 与WT组相比,NS组血糖明显升高[(6.8±0.3)比(32.2± 1.5) mmol/L,t=48.16,P＜0.05],体重明显降低[(28.4±1.0)比(23.0±1.5)g,t=8.284,P＜0.05];而NS组和PKK组相比,血糖及体重差异无统计学意义(P＞0.05).与WT组相比,NS组线粒体肿胀,微血管内微绒毛增多,微管结构排列紊乱,而上述病理改变在PKK组均有显著改善.与WT组相比,NS组DRGs中G6PD的表达明显降低(1.00±0.17比0.63±0.14,t=2.661,P=0.04),而PKK组G6PD水平明显上调(0.63±0.14比1.25±0.44,t=2.642,P=0.03).结论 PKK治疗能明显改善糖尿病所致的DRGs神经元的超微结构变化,其机制可能与上调G6PD、减轻氧化应激有关.

abstractsObjective To observe the protective effect of intraperitoneal injection of pancreatic kallikrein on peripheral neuropathy in type 1 diabetic mice.Methods Akita mice were used as type 1 diabetes mellitus model.The blood glucose and body weight were measured weekly.After the onset of hyperglycemia,the daily treatment was initiated and continued for up to 8 weeks.The mice were divided into three groups:wild type control group receiving saline infusion daily (WT group),diabetic control group receiving saline infusion daily (NS group) and diabetic treatment group receiving PKK daily (PKK group).At the end of treatment,the spinal dorsal root ganglions (DRGs) specific projection to the hind limb were collected from the mice.The ultrastructure of DRG neurons were examined by transmission electron microscopy.Quantitative real time polymerase chain reaction (Q-PCR) was used to detecte the expression of G6PD mRNA in three groups of DRGs.Friedman variance analysis was used to compare and analyze multiple samples.Results The blood glucose in NS group was significantly increased compared with the WT group [(6.8±0.3) vs (32.2± 1.5) mmol/L,t=48.16,P＜0.05] while the body weight in NS group was markedly lower than WT group [(28.4 ± 1.0) vs (23.0 ± 1.5) g,t=8.28,P＜0.05).There was no significant difference in blood glucose or body weight between NS group and PKK group (P＞0.05).Compared with WT group,NS group showed mitochondrial swelling,increased microvascular microvilli and disorganized microtubule structure.These pathological changes were improved in PKK group.The expression of G6PD mRNA in NS group was significantly lower compared with WT group (1.00±0.17 vs 0.63±0.14,t=2.661,P=0.04),and the G6PD mRNA expression was significantly increased in PKK group (0.63±0.14 vs 1.25±0.44,t=2.642,P=0.03).Conclusion PKK improved the ultrastructural changes of DRG neurons in diabetic mice,which may be related to the up-regulation of G6PD and the reduction of oxidative stress.