糖尿病大鼠肾小球系膜细胞表型转化及菟箭合剂的作用

目的：研究糖尿病大鼠是否存在肾小球系膜细胞表型转化及中药菟箭合剂的作用。方法：SD大鼠分为正常对照组(NC组，n=8)、单肾切除对照组(QC组，n=8)、单肾切除链脲佐菌素(STZ)糖尿病组(DM组，n=8)、缬沙坦治疗组(VT组,n=8)和中药菟箭合剂治疗组(ZY组，n=9)，缬沙坦治疗组和菟箭合剂治疗组分别在单肾切除STZ糖尿病模型成模后灌喂缬沙坦[20mg／(kg·d)]和菟箭合剂[20g／(kg·d)]12周，用免疫组化的方法观察大鼠肾小球内α-平滑肌肌动蛋白(alpha smooth muscle actin，α-SMA)和转移生长因子-β1(TGF-β1)的表达情况，用计算机病理图像分析软件检测肾小球α-SMA和TGF-β染色阳性面积／肾小球毛细血管袢面积比。结果：NC组和QC组大鼠仅个别肾小球内有少量α-SMA阳性显色，DM组大鼠肾小球内可见显著的α-SMA阳性显色，肾小球内α-SMA阳性面积／肾小球毛细血管袢面积比和TGF-β1阳性面积／肾小球毛细血管袢面积比显著增加(P<0．01)，24h尿蛋白排泄量较NC组和QC组大鼠显著增多(P<0．01)；VT组和ZY组大鼠24h尿蛋白排泄量较DM组显著减少，肾小球内α-SMA阳性面积／肾小球毛细血管袢面积比和TGF-β阳性面积／肾小球毛细血管袢面积比较DM组显著降低(P<0．01)；ZY组24h尿蛋白排泄量较VT组低(P<0．01)。结论：单肾切除STZ糖尿病大鼠肾小球内可见大量的α-SMA的表达，提示糖尿病肾病时存在肾小球系膜细胞表型转化，中药菟箭合剂和缬沙坦治疗后可显著减少糖尿病大鼠24h尿蛋白排泄量，抑制肾小球系膜细胞表型转化和肾小球内TGF-β的表达，菟箭合剂较缬沙坦降低糖尿病大鼠24h尿蛋白排泄量的作用更为显著。

Phenotypic Modulation of Mesangial Cells in Diabetic Rats and Effect of Tujian Mixture

OBJECTIVE: To explore whether there is phenotypic modulation of mesangial cells in streptozotocin (STZ) induced diabetic rats and study the effect of Tujian Mixture (TJM) on it. METHODS: SD rats were divided into the normal control group (NC group, n = 8), the unilateral nephrectomized control group (QC group, n = 8), the STZ induced diabetes mellitus with unilateral nephrectomy model group (DM group, n = 8), the Valsartan treated group (VT group, n = 8) and the TJM treated group (ZY group, n = 9), rats in the latter two groups were modeled as in the DM group and treated with Valsartan (20 mg/kg.d) and TJM (20 g/kg.d) respectively for 12 weeks. The expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta 1 (TGF-beta 1) in rats glomeruli were observed by immunohistochemistry assay, and the ratio of alpha-SMA and TGF-beta 1 positive area/total glomerule tuft area (SMA/GT and TGF/GT) were analyzed using computer-assisted image analysis software. RESULTS: In the NC and the QC groups, only trace of alpha-SMA positive staining was found. But there was prominant alpha-SMA positive staining in glomeruli of the DM group, with SMA/GT and TGF/GT increased significantly (P < 0.01), and marked increase of 24 hrs proteinuria excretion (P < 0.01). As compared with the DM group, the three indexes were all significantly lower in the VT and ZY groups (P < 0.01), and the lowering of proteinuria was more significant in the ZY group than that in the VT group (P < 0.01). CONCLUSION: The expression of alpha-SMA in glomeruli in STZ induced diabetic rats with unilateral nephrectomy is pronounced, indicating that phenotypic modulation of mesangial cells involvement in the pathogenesis of diabetic nephropathy. TJM and Valsartan can reduce 24 hrs proteinuria excretion, inhibit the phenotypic modulation of mesangial cells and the expression of TGF-beta 1 in glomeruli of diabetic rats, and the effect of TJM is more potent than that of Valsartan in lowering urinary protein excretion.