低剂量电离辐射对糖尿病小鼠肾功能及形态学的影响

Effects of low dose radiation on kidney function and morphology of diabetic mice

目的:研究低剂量电离辐射(LDR)对STZ诱导的糖尿病肾病(DN)小鼠肾脏形态及功能的影响,阐明低剂量电离辐射对糖尿病引起的肾脏形态及功能损伤的保护作用。方法:选取健康适龄C57BL/6J小鼠,随机分为空白对照组、糖尿病组(DM)、LDR组和DM/LDR组。DM与DM/LDR组经腹腔注射STZ,建立DM模型,另两组给予等量枸橼酸溶液。造模后DM/LDR与LDR组给予25mGyLDR隔日照射,共照射4周。在照射后2、4、8、12及16周检测各组小鼠血糖水平、肾功能指标因子以及肾脏形态学。结果:造模后DM和DM/LDR组小鼠血糖水平显著高于LDR和对照组小鼠(P<0.05),LDR处理2周后DM/LDR组小鼠血糖水平明显受到抑制,显著低于DM组(P<0.05),且这种改变一直保持到16周。与另外3组相比,DM/LDR组小鼠尿液中微量白蛋白(MALB)水平降低(P<0.05),肌酐(Cre)水平升高(P<0.05)。形态学检测,DM/LDR组小鼠肾小球系膜基质增多及系膜细胞增生较DM组减轻,肾小球结构改变较DM组减轻,而LDR和空白对照组肾小球及肾小管未见异常。结论:LDR能有效降低血糖,缓解糖尿病高血糖所引起的肾脏功能改变,抑制和延缓DN的病理改变。

Objective To study the effect of low dose radiation（LDR） on the kidney function and morphology in C57BL/6J mice with diabetic nephropathy（DN）induced by streptozotocin（STZ） and illuminate the protective function of LDR on kidney damage caused by diabetes mellitus（DM）.Methods The healthy and right age C57BL/6J mice were divided into 4 groups including control,DM,LDR and DM/LDR.The mice in DM and DM/LDR groups were injected intraperitoneally with STZ to set up DM models.The mice in DM/LDR and LDR groups were irradiated with 25 mGy X-rays every other day for 4 weeks.The changes of blood glucose level,urine index level and the morphology of glomerular were detected at 2,4,8,12,16 weeks after radiation.Results The blood glucose levels of mice in DM and DM/LDR groups after STZ-induced DM model preparation were higher than those in LDR and control gourps（P0.05）.After treated with LDR for 2 weeks,the blood glucose level in DM/LDR group was supressed and significantly lower than that in DM group （P0.05）.Moreover the the change had been kept to 16 weeks. In addition,compared with DM group,the level of urine micro albumin（MALB） in DM/LDR group was decreased and the urine creatinine（Cre） level was increased.Compared with DM group,the morphological results showed that the glomerular mesangial expansion and mesangial cell proliferation were significantly supressed in DM/LDR group（P0.05）.Conclusion LDR can promote the decease of blood glucose level efficiently,relief the change of kidney fuction,supress and delay the pathological changes of DN.