氯美噻唑对乙醇诱导大鼠肝损伤的抑制作用研究

Inhibitory effect of Clormethiazole on ethanol- induced liver injury in rats

摘要:

目的 探究氯美噻唑（CMZ）在乙醇诱导大鼠肝损伤模型中的作用。方法 将32 只雄性SD 大 鼠随机分为4 组：葡萄糖对照组、乙醇模型组、乙醇＋ CMZ 组、葡萄糖＋ CMZ 组，每组8 只。乙醇模型 组大鼠连续2 个月灌胃乙醇[0.1 ml/（kg·d）]，乙醇＋ CMZ 组、葡萄糖＋ CMZ 组连续2 个月灌胃CMZ 80 mg/（kg·d）。2 个月后体内采用6- 羟基氯唑沙宗/ 氯唑沙宗比值评估氯唑沙宗（CHZ）代谢的程度，以 检测大鼠体内细胞色素P450 2E1（CYP2E1）的活性；眼眶取血检测血浆乙醇浓度和谷丙转氨酶活性；随后 处死所有大鼠，分离肝脏，比较各组相对肝重，制备肝匀浆，检测大鼠肝脏蛋白酶体的活性，制备肝微粒体， 采用Western blot 检测大鼠肝脏CYP2E1、CYP3A、CYP4A 相对表达量；固定光镜观察肝组织病理学变化。 结果 乙醇+CMZ 组与乙醇模型组相比，能够降低大鼠肝损伤（P <0.05）。乙醇能够诱导CYP2E1 蛋白的表 达，乙醇+CMZ 组同样诱导CYP2E1 的表达。CMZ 抑制乙醇模型组大鼠体内乙醇诱导的CYP2E1 活性，但 未影响CYP2E1 蛋白的表达。同样，CMZ 阻断乙醇诱导的蛋白酶体活性下降。结论 CMZ 通过抑制大鼠体 内CYP2E1 的活性，而降低乙醇诱导的肝损伤。

Abstract:

Objective To study the effect of Clormethiazole (CMZ) in rat model of liver injury induced by ethanol. Methods Thirty-two male SD rats were randomly divided into four groups: a glucose control group (n = 8), an ethanol model group (n = 8), an ethanol+CMZ group (n = 8) and a glucose+CMZ group (n = 8). The rats in the ethanol model group were fed with ethanol 0.1 ml/(kg·d) for 2 m, and the rats in the ethanol+CMZ group and the glucose+CMZ group were fed with CMZ 80 mg/(kg·d) for 2 m. Then Chlorzoxazone metabolism was measured in vivo (6-OH CHZ/CHZ ratio, μg/ml) to assess the activity of cytochrome P450 2E1 (CYP2E1). Blood samples were collected from the orbit to detect serum ethanol content and serum alanine aminotransaminase (ALT). Then all rats were sacrificed under anesthesia, the relative liver weight was compared among the groups; liver homogenate was prepared to detect the proteasome activity; the relative expressions of CYP2E1, CYP3A and CYP4A in rat liver were assessed by Western blot; and pathological changes were observed under microscope and their degrees were evaluated by morphormetry. Results Compared with the ethanol model group, the ethanol+CMZ group could significantly reduce the liver injury in the rats (P < 0.05). Ethanol induced the expression of CYP2E1 protein (P < 0.05), the ethanol+CMZ group also induced the expression of CYP2E1 (P < 0.05). Detection of Chlorzoxazone hydroxylation product revealed that CMZ inhibited activity of CYP2E1 in the ethanol model group (P < 0.05), but the expression level of CYP2E1 protein was not affected (P > 0.05). CMZ blocked the decrease in ethanol-induced proteasome activity (P < 0.05). Conclusions CMZ can protect the liver from injury induced by ethanol through inhibiting the activity of CYP2E1.