中文摘要：

目的：研究蛹虫草（Cordyceps militaris）对糖尿病大鼠肾脏病程发展的抑制作用。方法：采用一次性腹腔注射链脲佐菌素（STZ）的方法建立糖尿病大鼠模型。经蛹虫草（400mg/kg,以体质量计）灌胃8周后,分别检测大鼠空腹血糖值和肾脏指数;并收集大鼠24h尿液,检测尿液中微量白蛋白（mAlb）、β-N乙酰葡萄糖苷酶（NAG）含量;测定血清中尿素氮（BUN）、肌酐（Cr）、尿酸（UA）含量;通过RT-PCR法测定肾脏中转化生长因子β1（TGF-β1）及其Ⅱ型受体（TβRⅡ）、结缔组织生长因子（CTGF）mRNA表达;Western blotting检测肾脏中TGF-β1蛋白表达;免疫组化法检测肾脏中Ⅳ型胶原表达。结果：蛹虫草能显著降低糖尿病大鼠空腹血糖（P〈0.05）、肾脏指数（P〈0.01）、24h排尿量（P〈0.01）、尿微量白蛋白排泄率（UAER）（P〈0.01）和NAG排泄率（P〈0.01）;同时能够降低血清中BUN、Cr、UA含量（P〈0.05）;下调TGF-β1、TGFβRⅡ和CTGF的mRNA表达（P〈0.01）,减少TGF-β1及Ⅳ型胶原的蛋白表达（P〈0.01）。结论：蛹虫草具有良好的降血糖及改善肾脏滤过功能的作用,其机制可能与抑制TGF-β1、TGFβRⅡ和CTGF等基因表达,减少胶原物质在肾脏中的积累有关。

英文摘要：

Objective： To explore the inhibitory function of Cordyceps militaris on the development of nephropathy in diabetic rats.Methods： Diabetic rat model was established by intraperitoneally injecting streptozotocin at the dose of 60 mg/kg.After the diabetic rats were administered with Cordyceps militaris at the dose of 400 mg/kg for 8 consecutive weeks,fasting blood glucose level,kidney index,the contents of microalbumin（mAlb） and β-N acetyl glucosaminidase（NAG） in urine,and the contents of blood urea nitrogen（BUN）,creatinine（Cr） and uric acid（UA） in serum were determined.The mRNA expression of transforming growth factor-β1（TGF-β1）,transforming growth factor beta-receptor II（TGFβR II） and connective tissue growth factor（CTGF） in the kidney were evaluated by semi-quantitative RT-PCR.The expression of collagen IV and TGF-β1 protein in the kidney was determined by immunohistochemistry and Western blot analysis.Results： C.militaris could significantly reduce fasting blood glucose（P0.05）,kidney index（P0.01）,24-h urine collection（P0.01）,the excretion of mAlb（P0.01） and NAG（P0.01） in urine,and serum BUN,Cr and UA levels（P0.05） of diabetic rats.C.militaris administration resulted in a remarkably down-regulation of TGF-β1,TGFβR II and CTGF mRNA expression in the kidney of diabetic rats（P0.01）.Western blot and immunohistochemistry analyses revealed a reduction in the expression of TGF-β1 and collagen IV protein due to C.militaris administration.Conclusion： C.militaris has anti-hyperglycemic function and can improve kidney filtration function.The mechanisms of these functions may be due to the inhibited expression of TGF-β1,TGFβR II and CTGF as well as the reduced accumulation of collagen in the mouse kidney.