中药复方消可宁颗粒剂增加糖尿病大鼠微动脉抗氧化应激作用

目的探讨消可宁颗粒剂对糖尿病大鼠微动脉氧化损伤的保护作用及机制。方法采用链脲佐菌素制备糖尿病大鼠模型。糖尿病造模成功后21天,处死大鼠,无菌条件下取出肠系膜微动脉进行离体灌注,血管内分别给予1、3和5 g/L消可宁溶液,在培养箱中培养24、48、72 h后,用比色法检测各组肠系膜微动脉中超氧化物岐化酶（superoxide dismutase,SOD）、黄嘌呤氧化酶（xanthine oxidase,XOD）的活性。用Western blotting方法检测肠系膜微动脉中锰超氧化物歧化酶（Mn-superoxide dismutase,Mn-SOD）含量。结果糖尿病组大鼠肠系膜微动脉SOD活性、Mn-SOD含量较正常对照组低（P〈0.05）,经过不同浓度消可宁处理后SOD活性、Mn-SOD含量逐渐恢复,随着消可宁浓度增高和作用时间延长SOD活性则恢复较明显,消可宁浓度为5 g/L。培养72 h时Mn-SOD含量与正常对照组之间的差异无统计学意义。糖尿病组大鼠肠系膜微动脉XOD活性较正常对照组高（P〈0.05）,经过不同浓度消可宁处理后XOD活性逐渐降低,随着消可宁浓度增高和作用时间延长则XOD活性降低较明显（P〈0.05）。结论糖尿病时微动脉发生氧化应激损伤,消可宁可以抵抗微动脉氧化应激损伤。其机制可能与消可宁可以有效地抑制糖尿病微动脉XOD活性,提高SOD活性和含量,减少氧自由基生成有关。

Protective effect of Xiaokening on the oxidative stress of mesenteric arterioles in the diabetic rats

Objective To investigate the protective effect of Xiaokening on the oxidative stress of mesenteric arterioles in the diabetic rats and the underlying mechanism.Methods Diabetic model was induced by injection of streptozotocin（60 mg/kg,i.p.）.21 days after model inducement,the rats were sacrificed and mesenteric arterioles were isolated in sterilization for in vitro perfusion with intravascular injection of Xiaokening（1,3 and 5 g/L） and cultured in an incubator for 24,48 and 72 hours,respectively.The activity of（superoxide dismutase） SOD and（xanthine oxidase） XOD was determined by colorimetry at the end of experiment.The expression of Manganese superoxide dismutase（Mn-SOD） in mesenteric arterioles was assessed by Western blot.Results Compared to normal control group,the activity of SOD and expression of Mn-SOD decreased in diabetic rats（P0.05）.Pretreatment with different concentrations of Xiaokening caused a gradual retrieval of SOD activity and Mn-SOD protein level.A marked retrieval was observed in the activity of SOD with the increase in the concentration and action duration of Xiaokening,while the Mn-SOD level in the mesenteric arterioles cultured at 5g/L for 72 h had no statistical difference as compared to the normal control group.The XOD activity in the mesenteric arterioles increased in the diabetic rats（P0.05）.Following Xiaokening treatment at different concentrations,XOD activity markedly decreased with the increase in the concentration and action duration（P0.05）.Conclusion Xiaokening could significantly reduce diabetes-induced oxidative stress of mesenteric arterioles,which might be attributed to its effects on the inhibition of the XOD activity,increase in SOD level and activity as well as the reduction of the formation of oxygen free-radicals.