内皮素-1受体拮抗剂PD142893对肝硬化大鼠肝脏Ⅰ型胶原、Ⅲ型胶原表达的影响以及和肝纤维化关系

Effect of mixed ET A/B receptor antagonist on collagen Ⅰ and collagen Ⅲ in rats with liver cirrhosis： role of PD142893

目的探讨内皮素受体拮抗剂是否对CCl4引起的大鼠肝纤维化有阻滞作用。方法实验中采用的是通过CCl4损伤引起的肝硬化门脉高压大鼠模型，随机分为正常对照组、肝硬化模型组、PD142893（ETA／B双受体拮抗剂）治疗组。治疗组在用CCl4造模的同时皮下注射PD142893（12．5μg／kg），2次／d，直到造模结束，取部分肝组织用甲醛固定后行HE染色和Masson染色并进行肝硬化分级；然后根据染色结果制作组织芯片并行免疫组化染色，检测Ⅰ型胶原、Ⅲ型胶原的蛋白表达并进行半定量分析。取部分肝组织用RT-PCR法检测Ⅰ型胶原、Ⅲ型胶原的mRNA表达并进行半定量分析。结果肝硬化分级和Masson染色胶原半定量结果证实肝硬化模型组、PD治疗组大鼠肝纤维化程度明显加重，与对照组比较有非常显著性差异（P〈0．01）；而PD治疗组的肝纤维化程度较模型组明显减轻，差别有显著性意义（P〈0．05）。Ⅰ型胶原、Ⅲ型胶原免疫组化蛋白表达及mRNA表达结果证实肝硬化模型组与对照组、PD治疗组比较明显上调（P〈0．05）。结论ET A/B双受体拮抗剂可以有效地下调CCl4引起的肝纤维化大鼠的Ⅰ型胶原、Ⅲ型胶原的蛋白表达和mRNA表达，进而抑制大鼠肝纤维化的发展。

Objective To determine whether ET-1 receptor antagonist can arrest or reverse the progression of hepatic fibrosis after carbon tetrachloride （CCl4） induced liver cirrhosis in rats. Methods Hepatic cirrhosis with portal hypertension was induced in S-D rats by 50% CCl4 treatment （3 ml/kg, intragastric administration, once/five days）. These rats were randomized into the normal control group, model group and PD treatment groups. Rats of PD treatment group were then treated respectively with PD142893 （mixed ET A/B receptor antagonist, 12. 5μg/kg）, twice a day, by hypodermic injection, concurrently with CCl4. The treatment continued for 75 d. And then the rats were executed after anaesthesia. Formalin-fixed sections of the liver were stained with HE and Masson. Inflammation and fibrosis were assessed histologically. The tissue array was made based on the results of HE staining. Collagen Ⅰ and collagen Ⅲ were determined with immunohistochemistry. Relative mRNA expression of collagen Ⅰ and collagen Ⅲ were determined by semiquantitative reverse transcriptase-polymerase chain reaction （RT-PCR）. Results The liver fibrosis severity was significantly higher in the model group and PD142893 treatment group than in the normal group （P〈0.01）. Meanwhile, it was markedly higher in the PD142893 treatment group than in the model group. The expression of protein and mRNA of collagen Ⅰ and collagen Ⅲ were significantly up-regulated in the model group as compared with other groups （P〈0. 05）. Conclusions Mixed ET A/B receptor antagonist can effectively cause down-regulation in expression of protein and mRNA of collagen Ⅰ and collagen Ⅲ in rats after hepatic fibrosis induced by CCl4 in rats.