川芎嗪对肝硬化大鼠瘦素及其受体表达的干预作用

Intervention of Tetramethylpyrazine on Expression of Leptin and its Receptor in Cirrhotic Rats

背景:瘦素与肝纤维化关系密切,但其在肝硬化形成过程中的作用机制不明。目前使用的抗肝硬化药物疗效均不满意。目的:观察瘦素及其功能性受体(Ob-Rb)在大鼠肝硬化形成过程中的表达变化,以及川芎嗪对两者表达的干预作用,探讨川芎嗪抗肝纤维化的作用机制。方法:诱导CCl_4大鼠肝纤维化模型。川芎嗪预防组和治疗组分别于实验第1d和第31d开始予川芎嗪每天10mg/100g体重干预。于12周内分批处死各组大鼠。以逆转录聚合酶链反应(RT-PCR)检测肝组织瘦素和Ob-Rb mRNA表达,以免疫组化方法检测瘦素和Ob-Rb的表达和定位,同时行血清透明质酸(HA)水平检测和肝内胶原定量分析。结果:正常肝组织中有少量瘦素和Ob-Rb mRNA表达,随着肝硬化的形成,两者表达逐渐增加,与血清HA水平和肝内胶原含量呈正相关。肝硬化模型组汇管区、纤维间隔、小叶内血管、胆管、肝窦周围瘦素和Ob-Rb表达明显增加,表达强度从第3～12周呈递增趋势。川芎嗪预防组和治疗组瘦素和Ob-Rb及其mRNA表达均低于肝硬化模型组,两组血清HA水平和肝内胶原含量亦显著低于肝硬化模型组。结论:瘦素和Ob-Rb在肝硬化形成过程中发挥重要作用。川芎嗪能下调CCl_4肝纤维化大鼠肝组织瘦素和Ob-Rb的表达,这可能是其抗肝纤维化的作用机制之一。

Background：Studies have shown that leptin is closely correlated with liver fibrosis, however, its mechanism in the development of liver cirrhosis is not clear yet. The efficacy of anti-cirrhotic agents used clinically is not satisfactory. Aims： To observe the dynamic expression of leptin and its long form receptor （Ob-Rb） in the developing process of liver cirrhosis in rats, and the interventional effect of tetramethylpyrazine （TMP） on the expression of leptin and Ob-Rb, so as to investigate the mechanism of TMP against liver fibrosis. Methods： 60% CCl4 was injected subcutaneously to induce liver fibrosis model in rats. The animals in prevention and treatment groups were given TMP 10 mg/100 g per day from the 1st and 31st day of induction, respectively. All the animals in the experimental groups were sacrificed within 12 weeks in batch. Expression of leptin and Ob-Rb mRNA in liver tissue was detected by reverse transcriptase polymerase chain reaction （RT-PCR）, and the expression and distribution of leptin and Ob-Rb by immunohistochemistry. Measurements of serum level of hyaluronic acid （HA） and quantitative analysis of collagen in liver tissue were conducted simultaneously. Results： Leptin and Ob-Rb mRNA expressed slightly in the normal liver tissue, and increased gradually after CCL injection, which were positively correlated with the serum level of HA and collagen amount in liver tissue. Up-regulated expression of leptin and Ob-Rb was observed in the portal area, septum, perivascular and perisinusoidal areas of hepatic lobule, and bile duct in cirrhotic model group, the intensity of expression increased in a time-dependent manner from the 3rd to 12th week. Expression of leptin and Ob-Rb and its mRNA in TMP prevention and treatment groups decreased significantly when compared with those in the cirrhotic model group, so did the serum HA level and collagen amount in liver tissue. Conclusions： Leptin and Ob-Rb are involved in the development of liver cirrhosis. Inhibition of hepatic leptin and Ob-Rb might be one of the mechanisms of TMP against liver fibrosis in CCL-induced fibrotic rats.