抗坏血酸对糖尿病大鼠肾脏缺血-再灌注后肾小球内皮多糖-蛋白复合物的影响

Effects of ascorbic acid on glomerular endothelial cell protein complex in diabetic rats with renal ischemia-reperfusion injury

目的观察抗坏血酸预处理对糖尿病大鼠肾脏缺血-再灌注后肾小球内皮多糖-蛋白复合物的影响。方法 32只SD健康清洁大鼠随机均分为四组：A组为正常血糖大鼠,B、C、D组首先建立糖尿病模型,A、B组为假手术组,麻醉后行腹部正中切口,小心分离暴露双侧肾蒂游离肾动脉,30min后关闭腹腔;C组每天腹腔注射生理盐水0.5ml,15d后建立肾脏缺血-再灌注模型;D组每天腹腔注射抗坏血酸200 mg/kg 0.5 ml,15d后建立肾脏缺血-再灌注模型。观察大鼠术前30 min（T_1）、游离肾动脉后（T_2）、术后30 min（T_3）、术后6h（T_4）、术后24h（T_5）的血糖（Glu）、尿素氮（BUN）、肌酐（Cr）、丙二醛（MDA）、超氧化物歧化酶（SOD）的变化,检测术后24h半胱天冬酶-3（caspase-3）、细胞色素C（CytC）和多糖-蛋白复合物的表达情况。结果C、D组大鼠在T_3~T_5时BUN、Cr、MDA水平明显高于A、B组,SOD水平明显低于A、B组（P〈0.05）。与C组比较,D组大鼠T_3~T_5时BUN、Cr、MDA水平明显降低,SOD水平明显升高,caspase-3、CytC表达水平明显降低,肾小球内皮多糖-蛋白复合物的厚度明显增加,肾组织损伤明显改善（P〈0.05）。结论抗坏血酸预处理可通过减轻糖尿病大鼠肾缺血-再灌注后肾小球内皮多糖-蛋白复合物的损伤从而减轻糖尿病大鼠肾缺血-再灌注损伤。

Objective To observe the effect of ascorbic acid preconditioning on the glomerular endothelial polysaccharide protein complex in diabetic rats after renal ischemia and reperfusion.Methods A total of 32 healthy SD rats were randomly divided into 4groups,group A with normal blood glucose,groups B,C and D diabetic rats,Groups A and B were sham operation groups,after anesthesia,rats were made abdominal median incision and had separation to expose the bilateral renal pedicle and free renal artery carefully,abdominal incision were closed 30 minutes later;rats in group C were injected with normal saline 0.5ml daily for fifteen days,while rats in group D were injected with ascorbic acid 200mg/kg（0.5ml）daily for 15 days,both groups C and D then made renal ischemia reperfusion model;modeling methods：after anesthesia,rats were made abdominal median incision and had separation to expose the bilateral renal pedicle and free renal artery carefully,clipped renal artery with vascular clamp for 30 minutes then released forceps and had reperfusion for 24 hours.To observe the changes of blood glucose,blood urea nitrogen（BUN）,creatinine（Scr）,malondialdehyde（MDA）,superoxide dismutase enzyme（SOD）at 30 minutes before operation（T_1）,after freeing renal artery（T_2）,30 minutes after operation（T_3）,6hours after operation（T_4）and 24 hours after operation（T_5）,test the expression of caspase-3,cytochrome C（CytC）,polysaccharide protein complexes after operation for 24 hours.Results In groups C and D,the levels of BUN,SCr and MDA at T_3-T_5 were significantly higher than those in groups A and B,SOD level was significantly lower than group A and B（P0.05）.The levels of BUN,SCr,MDA at T_3-T_5 in group D were significantly decreased,SOD levels were significantly increased,caspase-3 and CytC expression were significantly reduced and a significant increase in the thickness of the glomerular endothelial polysaccharide protein complex,renal tissue injury significantly improved（P 0.05）when compared with group C.Conclusion Ascorbic acid preconditioning can reduce the injury of renal ischemia reperfusion injury in diabetic rats by reducing the injury of glomerular endothelial protein complex after renal ischemia reperfusion in diabetic rats.