目的：研究儿茶素对肾病综合征大鼠TGF-β1表达的影响。方法：20只SD雌性大鼠随机分成正常组、肾病组、激素组、儿茶素治疗组共4组。实验末应用生化法测定血清中白蛋白(Alb)、总蛋白(TP)、三酰甘油(TG)、BUN、转化生长因子 β1(TGF-β1)及24 h尿蛋白排泄量，分别应用免疫组化与原位杂交法检测肾固有细胞中TGF-β1与TGF-β1mRNA的表达，并应用半定量评分法对各组大鼠病理改变进行计量分析。结果：儿茶素治疗组大鼠血清中总TGF-β1 ［(59.40±8.12) μg/L］、活性TGF-β1 ［(47.56±9.88) μg/L］，肾组织中TGF-β1 ［(45.1±2.0)%］、TGF-β1mRNA 表达水平［(51.6±3.19)%］均明显低于肾病组［分别为(127.78±16.11) μg/L，(93.79±12.45) μg/L，(56.9±3.5)%，(60.4±4.8)%］(P<0.01)；与肾病组相比，儿茶素治疗组血清Alb明显增高，TG含量明显下降［(11.28±4.18) g/L vs (1.46±0.71) g/L；(2.89±0.64) mmol/L vs (6.02±0.90) mmol/L；P<0.01］；与肾病组相比，儿茶素组大鼠肾脏病理损害明显减轻(P<0.05)。结论：儿茶素可通过抑制TGF-β1 mRNA的表达，降低肾脏局部及血清中活性TGF-β1蛋白表达水平，减轻肾脏损伤，改善肾功能，延缓肾脏病理慢性进展。

OBJECTIVE: To study the effect of catechin on transforming growth factor β1 (TGF β1) expression in rats with the nephrotic syndrome. METHODS:Twenty female SD rats were randomly assigned into the normal control group, un treated nephrotic group, dexamethasone treated nephrotic group and catechin treated nephrotic group. The concentrations of serum albumin (Alb), total protein (TP), trilyceride (TG), blood urea nitrogen (BUN) and TGF β1, and the excretion of 24 h urinary protein were detected by the biochemical assay; the TGF β1 and TGF β1 mRNA expressions in renal intrinsic cells were measured by the immunohistochemical technique and in situ hybridization (ISH) respectively; a semiquantitative score was used to evaluate the degree of glomerular and tubulointerstitium. RESULTS: The serum total TGF β1 [( 59.40 ± 8.12 ) μg/L] and activated TGF β1 [( 47.56 ± 9.88 ) μg/L], TGF β1 and TGF β1 mRNA expressions in renal intrinsic cells [( 45.1 ± 2.0 ) % and ( 51.6 ± 3.2 ) %] in the catechin treated nephrotic group were lower than those in the un treated nephrotic group [( 127.78 ± 16.11 ) μg/L, ( 93.79 ± 12.45 ) μg/L, ( 56.9 ± 3.5 )% and ( 60.4 ± 4.8 )%, respectively](all P< 0.01 ). The serum Alb concentration increased significantly and the TG content obviously decreased in the catechin treated nephrotic group compared with the un treated nephrotic group [( 11.28 ± 4.18 ) g/L vs ( 1.46 ± 0.71 ) g/L; ( 2.89 ± 0.64 ) mmol/L vs ( 6.02 ± 0.90 ) mmolo/L] (both P< 0.01 ). The pathologic lesions of kidneys were remissive in the catechin treated nephrotic group compared with the nephrotic group. CONCLUSIONS: Catechin may alleviate kidney lesions and slow down the progression of kidney lesions by inhabiting the expression of TGF β1 mRNA and decreasing TGF β1 expression in renal intrinsic cells and serum activated TGF β1 expression effectively.