【摘要】 目的探讨低剂量电离辐射(LDR)对Ⅰ型糖尿病模型大鼠海马神经元细胞凋亡和氧化损伤的影响,阐明二者的关系。方法利用链尿佐菌素(STZ)建立Wistar大鼠糖尿病模型(DM)后,造模完成后分为正常组、模型组、模型+25mGy、模型+50mGy和模型+75mGy组,每组20只。给予25、50和75mGy隔日照射,共计12次,继续饲养4周后麻醉后处死大鼠,取出海马组织利用生化法检测海马中丙二醛(MDA)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活力;并利用流式细胞术检测细胞凋亡和活性氧(ROS)含量,并利用Western blot检测Bcl-2、Bax和caspase-3蛋白表达。结果Ⅰ型DM模型血糖显著高于正常对照组,而LDR可以显著降低模型大鼠的血糖(P<0.05)。同时,与正常组比较,DM模型海马细胞ROS水平和MDA含量显著增加(P<0.05),SOD和CAT活力未见显著变化;LDR照射后DM模型海马中ROS水平和MDA含量显著降低(P<0.05),但对SOD和CAT活力仍处于较低水平;另外,DM模型海马细胞凋亡百分比较正常对照组显著增加(P<0.05),Bcl-2蛋白表达降低,Bax和caspase-3蛋白表达增加,而LDR照射能够降低DM大鼠海马神经细胞的凋亡百分比,且升高Bcl-2蛋白表达,降低Bax和caspase-3蛋白表达。结论Ⅰ型糖尿病大鼠海马神经元细胞氧化损伤和凋亡增加,而LDR能显著降低这种作用,且涉及到Bcl-2、Bax和caspase-3蛋白的表达。更多还原

【Abstract】 Objective To investigate the effects of low dose radiation(LDR)on oxidative damage and apoptosis in hippocampal neurons of typeⅠ diabetes rats,and to elucidate the relationship between them.Methods Wistar rat diabetes model(diabetes mellitus,DM)was established by Streptozocin(STZ),there were Control,DM,DM+25 mGy,DM+50 mGy and DM+75 mGy groups after models constructed successfully,there 20 rats in each group.The doses of25,50 and 75 mGy were given to DM rats every other day for 12 times.Then after 4 weeks of feeding,the rats were killed after anesthesia.The hippocampus was removed,the MDA content,activities of SOD and CAT were detected by biochemical methods;ROS level and apoptosi were detected by FCM,and Bcl-2,Bax and caspase-3 expressions were measured by Western blot.Results The blood glucose of the type I DM model was significantly higher than that of the normal control group,while the LDR significantly decreased the blood glucose of the model rats(P<0.05).At the same time,compared with the normal group,the ROS level and MDA content in the hippocampus of the DM model were significantly increased(P<0.05),and the SOD and CAT activities were not significantly changed.The ROS level and MDA content in the hippocampus of the DM model after LDR irradiation were significantly decreased(P<0.05),but the activity of SOD and CAT is still at a low level.Additionally,the percentage of apoptosis in hippocampus of DM model is significantly higher than that of normal control group(P<0.05),the expression of Bcl-2 protein is decreased,and the expression of Bax and caspase-3 protein is decreased.Increased,while LDR irradiation can reduce the percentage of apoptosis in hippocampal neurons of DM rats,and increase the expression of Bcl-2 protein and decrease the expression of Bax and caspase-3 protein.Conclusion Oxidative damage and apoptosis of hippocampal neurons in type I diabetic rats increased,while LDR significantly reduced this effect and involved the expression of Bcl-2,Bax and caspase-3 proteins.更多还原