糖尿病大鼠肾皮质α平滑肌肌动蛋白表达与肾病发生的关系

目的　探讨早期抑制纤维化能否阻止大鼠糖尿病肾病的发生。方法　将72只SD大鼠随机分为3组:正常对照组、糖尿病组和干扰素γ(IFNγ)组。除正常对照组外,其余两组采用一次性ip链佐星70mg·kg- 1 ·d- 1 制备糖尿病模型。IFNγ组的糖尿病大鼠scIFNγ( 1 0 0kU·kg- 1 ·d- 1 )共8周。第1 ,2 ,4 ,8周每组各取6只大鼠,分别测定血糖、肾脏肥大指数、尿白蛋白,免疫组化法测定肾组织α平滑肌肌动蛋白(αSMA)和Ⅳ型胶原的表达,同时以酶联免疫吸附法测定肾皮质αSMA的含量。结果　第1 ,2 ,4 ,8周,IFNγ组大鼠肾皮质αSMA含量分别较糖尿病组减少3 6.9%,4 4.4 %,60 .4 %和4 0 .6%(P <0 .0 5 )。但IFNγ组肾脏Ⅳ型胶原表达、肾脏肥大指数均高于正常对照组(P <0 .0 1 ) ,与糖尿病组无显著性差异(P>0 .0 5 )。结论　该剂量IFNγ抑制肾组织αSMA表达,但不能阻止糖尿病肾病早期病变的发生

Relationship between expression of α smooth muscle actin and diabetic nephropathy in rats

AIM To investigate whether inhibition of fibrosis in early stage can prevent diabetic nephropathy in rats. METHODS Seventy-two Sprague-Dawley(SD) rats were randomly divided into 3 groups: normal control, diabetic and diabetic rats treated with IFNγ subcutaneously(100 kU·kg^-1·d^-1) for 8 weeks. Diabetic model was made by a single intraperitoneal injection of streptozocin in a dose of 70 mg·kg^-1. Six rats from each group were sacrificed at the end of week 1, 2, 4, 8, respectively. At each time-point, serum glucose, kidney hypertrophy index, urinary albumin excretion were detected. α Smooth muscle actin(αSMA) and collagen Ⅳ expression were studied by immunohistochemistry. The content of αSMA in renal cortex was also detected by enzyme-linked immunosorbent assay. RESULTS At the end of week 1, 2, 4 and 8, the content of α SMA in renal cortex of IFNγ group decreased 36.9%, 44.4%, 60.4% and 40.6%, respectively as compared with diabetic group（P<0.05, n=5,6）. Kidney hypertrophy index and collagen Ⅳ expression in IFNγ group were all higher than those of normal control rats, as well as diabetic rats. CONCLUSION Although IFNγ inhibits the expression of αSMA, it can′t prevent diabetic nephropathy.