补硒对输尿管梗阻大鼠肾间质纤维化及结缔组织生长因子表达的影响

EFFECT OF SODIUM SELENITE ON RENAL INTERSTITIAL FIBROSIS AND EXPRESSION OF CONNECTIVE TISSUE GROWTH FACTOR IN RATS WITH URETERAL OBSTRUCTION

目的探讨硒对单侧输尿管梗阻(UUO)模型大鼠肾间质纤维化的作用及其对肾间质结缔组织生长因子(CTGF)表达的影响。方法以单侧输尿管结扎致肾间质纤维化大鼠模型。将90只SD大鼠随机分为假手术组(A组)、UUO组(B组)、UUO+硒组(C组)、UUO+硒及维生素E组(D组)、UUO+苯那普利组(E组),每组18只。C、D、E组分别给予亚硒酸钠0.2 mg/(kg·d)、亚硒酸钠0.2 mg/(kg·d)+维生素E 200 mg/(kg·d)和亚硒酸钠0.2 mg/(kg-d)+亚苯那普利10 mg/(kg·d)灌胃。A、B组给予同等剂量生理盐水灌胃。术后第7、14、21 d各组随机处死6只大鼠,肾组织行HE、Masson染色评定各组肾间质纤维化程度,免疫组织化学半定量法检测各组肾间质结缔组织生长因子(CTGF)和转化生长因子-β1(TGF-β1)的表达。Western印迹法检测肾组织CTGF蛋白表达。化学比色法检测肾组织谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、丙二醛(MDA)的含量。结果术后第7,14,21 d,C组肾间质纤维化程度较B组明显减轻(P<0.05),肾组织CTGF和TGF-β1的表达强度明显低于B组(P<0.01或P<0.05),GSH-Px和SOD含量明显高于B组(P<0.05),MDA含量明显低于B组(P<0.05)。B组肾组织中CTGF和TGF-β1的表达以及肾间质纤维化指数与MDA含量呈显著正相关(P<0.05),而与SOD、GSH-Px含量呈显著负相关(P<0.05)。结论亚硒酸钠可以减轻UUO模型大鼠肾间质纤维化程度,其机制可能与硒的抗氧化作用、抑制肾组织TGF-β1、CTGF的表达有关。

Objective To investigate the effect of sodium selenite on renal interstitial fibrosis in rat model of unilateral ureteral obstruction （UUO）. Methods Ninety male SD rats were randomly divided into 5 groups： sham-operation group （group A）, UUO group （group B）, UUO＋sodium selenite group （group C）, UUO＋sodium selenite and vitamin E group （group D）, UUO ＋ benazepril group （group E）, with 18 in each group. Group C received sodium selenite 0.2 mg/（kg.d）, Group D received sodium selenite 0.2 mg/（kg.d）＋ Vitamin E 200 mg/（kg.d） and group E received sodium selenite 0.2 mg （kg ~ d）＋ benazepril 10 mg/（kg＇d） by gastric perfusion. A,B groups were given the equal volume 6f saline. At day 7, 14 and 21 after treatment, 6 rats were selected randomly from each group and killed. The extent of renal interstitial fibrosis was evaluated by HE and Masson staining. Immunohistochemical method and Western blot were used to estimate the expression of connective tissue growth factor （CTGF） and transforming growth factor-J31 （TGF-D1）. Renal cortex supper oxide dismutase （SOD）, malondialdehyde （MDA） and glutathione peroxidase （GSH-Px） were measured by colorimetric assay Results The extent of renal interstitial fibrosis and the expression of CTGF and TGF-[31 in renal cortex were significantly lower in group C at day 7, 14 and 21 after operation compared with that in group B （P^0.05 or P〈0.01 ） . In group C, the contents of SOD and GSH-Px in renal cortex were higher significantly than those in group B at day 7,14 and 21 respectively （P〈0.05） , but MDA in renal cortex was significantly decreased （P^0.05） . There were no significant differences in the extent of renal interstitial fibrosis, the expression of TGF-~l in renal cortex, the contents of SOD, GSH-Px and MDA in renal cortex among group C, D and E （P^0.05）. The expression of CTGF and TGF-[31 in renal cortex, and the extent of renal interstitial fibrosis was positively correlated to the level of MDA in group B （r = 0.843, P^0.05： r = 0.855, P^0.05; r = 0.818, P〈0.05, respectively） , and negatively correlated to the level of SOD （r =- 0.852, P〈0.05： r = -0.819, P〈0.05; r =- 0.824, P〈0.05, respectively） and GSH-Px （r = -0.875, P〈0.05： r = -0.837,P〈0.05： r = -0.832, P〈0.05,respectively） . Conelusion Sodium selenite may reduce the extent of renal fibrosis in rat UUO model.This effect may be related to antioxidant function and down-regulation of the expression of CTGF and TGF-1 in renal tissue.