霉酚酸酯在大鼠糖尿病肾病模型中的实验研究

Study of mycophenolate mofetil on diabetic nephropathy model in rats

目的探讨霉酚酸酯(MMF)在大鼠糖尿病肾病模型中的作用及其机制。方法SD大鼠随机分为3组:对照组(C组)、糖尿病组(D组)和糖尿病治疗组[M组,20mg/(kg·d)]。大鼠单侧肾脏切除后,腹腔注射链脲菌素(STZ)成糖尿病模型,对照组仅注射等量缓冲液。观察12周后,检测大鼠血糖(BG)、血尿素氮(BUN)、血肌酐(Scr)、肾脏肥大指数(肾重KW/体重BW)、肌酐清除率(Ccr)和24h尿蛋白(24Upro)。肾组织做常规光镜和电镜检查,观察组织形态。用免疫组织化学方法检测肾组织中单核细胞趋化蛋白(MCP-1)和巨噬细胞抗原(CD68)的蛋白表达。用半定量RT-PCR的方法检测肾组织中MCP-1的mRNA的表达。结果与对照组相比,糖尿病组大鼠BG、KW/BW、24Upro、BUN、Scr和Ccr均显著上升(P<0.05或0.01);肾小球系膜区相对面积和肾小球基底膜厚度均显著增加(P<0.01);肾组织内MCP-1和CD68的蛋白质表达及MCP-1的mRNA表达均显著上调(P<0.05或0.01)。在糖尿病治疗组,上述指标除血糖外都被显著抑制(P<0.05或0.01)。结论在糖尿病大鼠模型中,MMF能下调MCP-1的表达,减少单核/巨噬细胞的聚集,减少尿蛋白,从而达到对糖尿病肾病的保护作用。

[Objective] To assess the effects of mycophenolate mofetil（MMF） on diabetic nephropathy model in rats and explore its mechanism. [Methods] SD rats were divided randomly into there groups： control group（C）, diabetic group（D） and diabetic group treated with MMF [M, 20mg/（kg· d）]. SD rats were made diabetic by intraperitoneal injection of streptozotocin after uninephrectomy, the control group only injected the sham solution. Observed twelve weeks and their blood glucose（BG）, blood urea nitrogen（BUN）, serum creatinine（Scr）, kidey weight to body weight （KW/BW）, creatinine clearance（Ccr） and 24- hour urinary protein （24Upro） were detected. Glomerular structure and ultrastructrue of kidney were examined by light microscopy and electron microscopy. The protein exprssion of monocyte chemoattractant protein-l（MCP-1） and mac rophages antigen （CD68）in kidney tissure were determined by immunohistochemical technique. The mRNA expression of MCP-1 in kidney fissure were semi-quantitatively determined with reverse transcription-polymerase chain reaction（RT-PCR）. [Results] Compared with control group, the BG, KW/BW, 24Upro, BUN, Scr and Ccr were significantly increased in diabetic rats（P 〈0.05 or 0.01）, the relative area of glomerular mesangium and the depth of glomerular basement membrane were significantly enlarged （P〈0.01）, the protein expression of MCP-1 and CD68 and the mRNA expression of MCP-1 were significantly up-regulated （P 〈0.05 or 0.01）. In MMF treated group, the above mentioned parameters, except blood glucose were all signiilcantly inhibited （P 〈0.05 or 0.01）. [Conclusion] In diabetic rat model, MMF can down-regulate the exprssion of MCP-1 and decrease the gathering of the monoeytes/macrophages and urinary protein, so it show the protective effect for diabetic riephropathy.