氢溴酸槟榔碱体内对大鼠肝脏CYP2B表达的影响及其机制研究

In vivo effect of arecoline hydrobromide on rat hepatic CYP2B expression and its mechanism

目的研究氢溴酸槟榔碱对大鼠肝脏细胞色素P450 2B(CYP2B)表达的影响及其调控机制。方法 Wistar雄性大鼠连续ig氢溴酸槟榔碱(4、20、100 mg/kg)7 d,LC-MS/MS法检测肝脏CYP2B活性,Western blotting法检测肝脏CYP2B1/2、组成型雄甾烷受体(CAR)及核内CAR蛋白表达量,定量荧光PCR检测肝脏CYP2B1 mRNA表达量。结果氢溴酸槟榔碱对大鼠肝脏CYP2B蛋白的表达没有明显影响,但对肝脏CYP2B1 mRNA表达的诱导作用随剂量增加而增强,对CYP2B活性的诱导作用随剂量增加而减弱。此外,给药后肝细胞核内CAR蛋白量增加,但肝细胞总CAR蛋白的量无明显变化。结论氢溴酸槟榔碱体内通过促进CAR向核内转移,诱导了大鼠肝脏CYP2B活性,且对CYP2B的调控主要发生在转录水平,也可能存在翻译后修饰。

Objective To study the effect of arecoline hydrobromide （AH） on rat hepatic CYP2B expression/activity, as well as the underlying regulation mechanism in vivo. Methods After oral administration of AH （4, 20, and 100 mg/kg/d） to rats for 7 consecutive days, the hepatic CYP2B activity was detected by LC-MS/MS method, the protein levels of hepatic CYP2B, total CAR, and endonuclear CAR were detected by Western blotting, and the hepatic CYP2B1 mRNA level was detected by real-time PCR. Results AH treatment had no effect on rat hepatic CYP2B protein level, but the hepatic CYP2B1 mRNA level was dose-dependently increased. Additionally, although the hepatic CYP2B activity was induced by AH treatment, the induction was weakened with the dose increase of AH. Furthermore, the protein content of hepatic endonuclear CAR was increased while the total CAR protein remained unchanged following AH treatment. Conclusion AH induces rat hepatic CYP2B by promoting nuclear translocation of CAR. The regulation of AH on rat hepatic CYP2B largely involve transcriptional activation of the gene, partially involve the post-translational modification of CYP2B protein. Our results also suggest that the risk of metabolic interaction could be existed when the substrate drugs of CYP2B are administered in betel-quid used human.