通络方药对糖尿病肾病的保护作用与机制探讨

Protective effect of Tongluo recipe on diabetic nephropathy and its mechanism

目的:探讨通络方药对糖尿病大鼠肾脏损害的保护作用,及对肾皮质氧自由基代谢状态及抗氧化酶活性的影响。方法:选择雄性SD大鼠予链脲佐菌素55 mg/kg单次腹腔注射诱发糖尿病,3 d后血糖≥16.7 mmol/L者视为造模成功。将糖尿病模型鼠随机分为模型组(DM)、通络方药处理组(TLR)、褪黑素处理组(MEL),正常鼠作为正常对照组(CN),每组7只。TLR组每天灌服通络方药水溶液1 g/kg,MEL组灌服褪黑素溶液5 mg/kg,其余两组均灌服等体积稀释液。连续处理12周,麻醉下取肾脏组织进行电镜病理观察并用比色法测定肾皮质超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量。结果:与CN组相比,DM组大鼠24 h尿蛋白排泄量明显增加(P<0.01),经通络方药及褪黑素处理后,蛋白排泄量明显降低(P<0.01)。电镜下可见DM组大鼠肾小球系膜细胞和内皮细胞增生肿胀,足突融合、消失,系膜基质增多,基底膜厚度不均匀增加,线粒体数目增多、肿胀,线粒体嵴减少、形态紊乱。经Mel、通络方药处理后,上述改变有所好转。与CN组比较,DM组大鼠肾皮质内MDA含量升高,GSH-Px、SOD水平下降(P<0.05),经通络方药与褪黑素处理后,MDA含量较DM组有所下降,其中MEL组MDA含量下降更明显,显著低于DM组(P<0.05),GSH-Px、SOD水平稍有升高,但较DM组差异无统计学意义(P>0.05)。结论:通络方药可降低糖尿病大鼠肾脏蛋白排泄,改善肾小球基底膜结构,具有保护糖尿病肾病的作用;但其仅轻微降低肾脏MDA含量,抗氧化损伤作用不明确。

Objective.. To study the protective effect of Tongluo recipe on renal function of rats with diabetic nephropathy and its influenee on the oxidative stress and antioxidative system in renal cortex. Methods.. Diabetes mellitus was induced in male SD rats by intraperitoneal injection of streptozotocin（55 mg/kg）. Rats with a blood glucose level ≥16. 7 mmol/L after 3 days were taken as diabetic rats. Twenty-one diabetic rats were evenly randomized into 3 groups, namely, untreated diabetic control （DM group）, Tongluo recipe garaged （1 g · kg^-1· d^-1 for 12 weeks, TLR group）,and melatonin garaged （5 mg· kg^-1· d^-1 for 12 weeks, MEL group） groupsl normal rats were taken as normal control （NC group）. The treatments were started 3 days after streptozotocin injection and continued for 12 weeks. Kidney cortex was collected under anesthesia for electron microscopic observation. the kidney homogenates were prepared to determine the renal anti-oxidant enzyme（SOD, GSH-Px） activities and lipid proxide （MDA） levels by chromatometry. Results.. Compared with NC group, rats in DM group had a higher 24 hour-urinary protein excretion （P〈0.01）, while those in TLR group and MEL group were significantly lower than that of DM group （P〈 0. 01 ）. Electron microscopic results showed that the rnesangial ceils and endothelial ceils in DM group were swollen and had fusion/disappearance of podocytic process, increased mesenteric matrix, uneven basal membrane, and increased mitochondria with morphological disorders. while the above changes were improved in TLR and MEL group. GSH-Px and SOD activities were lower and MDA levels were higher in renal cortex of DM group than those of NC（P〈0.05） . treatment with Tongluo recipe and melatonin slightly increased SOD and GSH-Px activities and decreased MDA levels, with the level in MEL group significantly lower than that of DM group （P〈0.05）. Conclusion： Tongluo recipe can protect the renal function of diabetic rats by lowering urinary protein excretion and improving the structure of glomerular basement membrane, but it can only slightly decrease MDA level in the renal cortex, showing an unclear anti-oxidative effect.