普罗布考对糖尿病肾病大鼠氧化应激的影响

Effects of probucol on oxidative stress in rats with diabetic nephropathy

目的观察普罗布考（PB）对糖尿病肾病（DN）大鼠氧化应激的影响。方法60只Sprague—Dawley（SD）雄性大鼠随机分成4组：正常对照组（NC组）8只，右肾血管结扎组（RL组）8只，DN组22只，DN＋PB组22只。RL组、DN组和DN＋PB组首先进行右肾血管结扎，1周后DN组和DN＋PB组应用50mg／kg四氧嘧啶行尾静脉注射，72h测血糖高于16．7mmol／L视为糖尿病造模成功入组，造模成功率为82．5％。DN＋PB组给予每天1次170mg／kgPB灌胃，共3周。实验结束时NC组8只，RL组6只，DN组5只，DN＋PB组8只。收集24h尿量，处死各组大鼠并检测24h尿微量白蛋白（24hUMA）、肾脏肥大指数（LK／BW）、血糖、血尿素氮（BUN）、肌酐（Cr）、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、极低密度脂蛋白（VLDL）、高密度脂蛋白（HDL）水平，同时测定丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH—PX）的活性。左侧肾脏行HE染色病理检查。结果与NC组和RL组相比，DN组、DN＋PB组的血糖、LK／BW明显升高（P〈0．05）；与NC组、RL组、DN＋PB组相比，DN组的BUN、Cr、24hUMA、LDL、MDA明显升高（P〈0．05），SOD、CAT、SOD／MDA明显降低（P〈0．05）。与DN组相比，DN＋PB组上述指标则明显改善。与NC组相比，RL组、DN组、DN＋PB组的GsH—PX均升高（P〈0．05），而RL组、DN组和DN＋PB组3组之间无统计学差异（P〉0．05）。4组之间TC、TG、HDL、VLDL无差别（P〉0．05）。相关分析表明BG、BUN、Cr、24hUMA、LK／BW、LDL与MDA呈正相关（均P〈0．01），与SOD、SOD／MDA均呈负相关（均P〈0．01）。肾组织病理提示DN＋PB组较DN组在。肾小球增大、基底膜增厚、肾小球系膜基质增生、动脉壁增厚方面有所改善。结论MDA和SOD／MDA是衡量氧化和抗氧化的敏感指标，PB可以提高DN大鼠体内抗氧化酶的活性，降低氧化物质的含量，提供肾脏保护。抗氧化治疗是糖尿病肾病的一个具有潜能的治疗方式。

Objective To investigate the antioxidant effects of probucol（PB） on oxidative stress in diabetic nephropathy（DN） rats. Methods 60 Sprague-Dawley （SD） male rats were randomly divided into four groups： normal control group（ NC group, n = 8 ）, right renal blood vessel ligation group （RL group, n = 8 ）, DN group（ n = 22 ）, DN ＋ PB group （n = 22）. The right renal blood vessels were ligated in RL group, DN group and DN ＋ PB group. After a week the diabetic model was established by intravenous injection of alloxan with the dose of 50 mg/kg in DN group and DN ＋ PB group. 82.5% of rats whose 72 h blood glucose level were higher than 16.7 mmol/L were considered to be valid diabetic models. The rats in DN ＋ PB group were administrated with PB 170 mg/（kg · d） by a gastric tube for 3 weeks. The rats survived to the end of the ex- periment were 8 in NC group,6 in RL group,5 in DN group,8 in DN ＋ PB group. 24 h urine was collected be- fore the rats were sacrificed. 24 h urinary microalbumin （ UMA）, the kidney hypertrophy index （ LK/BW）, blood glucose （ BG）, blood urea nitrogen （ BUN ）, creatinine （Cr）, total cholesterol （ TC ）, triglyceride （ TG）, low density lipoprotein （ LDL ）, very low density lipoprotein （ VLDL ）, high density lipoprotein （ HDL ） were respectively examined. The activities of malondialdehyde （ MDA ）, superoxide dismutase （ SOD ）, catalase （CAT） and glutathione peroxidase （GSH-PX） were measured. The left kidney was stained by HE for patho- logical examination. Results Compared with those in NC group and RL group,BG and LK/BW were signifi- cantly increased in rats of DN group and DN ＋ PB group（P 〈0.05）. The levels of BUN,Cr,24 h UMA, LDL, MDA were significantly increased （ P 〈 0.05 ） and the levels of SOD, CAT, SOD/MDA were significantly decreased（P 〈0.05） in rats of DN group,compared with those in NC group,RL group and DN ＋ PB group. And the parameters mentioned above were significantly improved in rats of DN ＋ PB group, compared with those in DN group（P 〈0.05）. The level of GSH-PX increased in RL group,DN group and DN ＋ PB group, compared with NC group （ P 〈 0.05 ）, but it had no significant difference in RL group, DN group and DN ＋ PB group （P 〉 0.05 ）. The levels of TC, TG, HDL and VLDL had no statistical difference among the four groups （P 〉 0.05）. BG, BUN, Cr,24 h UMA, LK/BW, LDL had positive correlations with MDA （ P 〈 0.01 ） and had negative correlations with SOD and SOD/MDA （P 〈 0.01 ）. The size of glomerular volume, the thicke- ness of glomerular basement membrane and arterial wall, the hyperplasia of glomerular mesangial matrix on renal tissue pathology had improved in DN ＋ PB group, compared with DN group. Conclusion MDA and MDA/SOD may act as two sensitive markers to valuate oxidative and antioxidative state. PB may improve the activity of antioxidative enzyme in DN rats, reduce the concentration of oxidative substance, and provide a renoprotective effect. Antioxidative treatment could be a potential therapeutic procedure for DN.