己酮可可碱对小鼠酒精性肝病酒精代谢酶和核受体PPAR-α的影响

目的：研究己酮可可碱（PTX）对酒精性肝病小鼠酒精代谢酶和过氧化物酶增殖物激活受体（PPAR-α）的影响。方法将64只 C57BL/6小鼠随机分为模型组、治疗组和对照组，用50%酒精灌胃建立急性肝损伤模型，以20%酒精连续灌胃6周建立慢性酒精性肝病模型；采用比色法检测各组小鼠血清乙醇脱氢酶（ADH）和细胞色素 P4502E1（CYP2E1）活性；采用 RT-PCR 法检测肝组织 ADH、CYP2E1和 PPAR-α mRNA 水平；采用免疫组化法检测肝组织 CYP2E1和 PPAR-α蛋白表达。结果急性和慢性酒精性肝损伤模型小鼠血清 ADH 活性分别为（11.2±1.6）U/ml 和（5.8±1.4）U/ml，与相应对照组比无显著性差异分别为（12.5±1.2）U/ml 和（4.3±0.6）U/ml]；急性和慢性酒精性肝损伤小鼠 CYP2E1活性分别为（12.2±1.8）U/ml 和（11.8±1.7）U/ml，均显著高于对照组（7.9±1.4）U/ml 和（6.5±1.2）U/ml，P〈0.01）]和治疗组（8.1±1.5）U/ml 和（7.8±1.5）U/ml，P〈0.01]；急性和慢性酒精性肝损伤小鼠肝组织 CYP2E1阳性细胞相对表达强度为（765±21）和（682±25），均显著高于对照组分别为（308±12）和（305±18），P〈0.01）]和大剂量 PTX 治疗组分别为（521±18）和（418±12），P〈0.01]；急性和慢性酒精性肝损伤小鼠肝组织 ADH mRNA 水平与对照组比无显著性差异，但肝组织 CYP2E1 mRNA 相对水平分别为（1.47±0.32）和（1.13±0.52），显著高于对照组（0.89±0.23）和（0.45±0.28），P〈0.01）]及大剂量 PTX 治疗组分别为（0.92±0.27）和（0.48±0.32），P〈0.01）]；急性酒精性肝病动物肝组织 PPAR-α mRNA 水平与对照组或 PTX 治疗组比无统计学差异，但慢性酒精性肝损伤小鼠肝组织 PPAR-α mRNA 相对水平（0.45±0.31）]显著低于对照组（0.85±0.21），（P〈0.05）]；急性和慢性酒精性肝损伤小鼠肝组织 PPAR-α阳性相对表达强度为（322±15）和（262±23），均显著低于对照组分别为（721±18）和（689±14），（P〈0.01）]和大剂量 PTX 治疗组分别为（548±20）和（725±19），P〈0.01）]。结论 PTX 能够减轻急慢性酒精性肝损伤，可能与其上调酒精代谢酶 CYP2E1和下调 PPAR-α表达有关，而与ADH 无关。

Effects of pentoxifylline on ethanol metabolic enzymes and peroxisome proliferator-activated receptor alpha in mice with alcoholic liver disease

Objective To investigate the effect of pentoxifylline （PTX） on ethanol metabolic enzymes and peroxisome proliferator-activated receptor alpha （PPAR-α） in C57BL/6 mice with alcoholic liver disease. Meth-ods Sixty -four mice were randomly divided into alcoholic liver disease model, PTX intervention and control group; Acute alcoholic liver injury was induced in mice by intragastric administration with 50% alcohol,and chronic alcoholic liver injury was induced by intragastric administration with 20% alcohol daily for six weeks;Serum alcohol dehydrogenase （ADH） and cytochrome P4502E1 （CYP2E1） activity was measured by colorimetric method;The mRNA levels of ADH,CYP2E1 and PPAR-α were measured by PT-PCR;The protein expression of CYP2E1 and PPAR-α was determined by immunohistochemistry. Results The serum activity of ADH did not differ among mice with acute （11.2±1.6）U/ml] or chronic （5.8±1.4） U/ml] alcoholic liver injury and controls （12.5±1.2）U/ml and（4.3±0.6）U/ml,respectively];In mice with acute and chronic liver injury,the CYP2E1 activ-ity was（12.2±1.8）U/ml and（11.8±1.7） U/ml,respectively,significantly higher than those in normal controls（7.9±1.4） U/ml and （6.5±1.2） U/ml,P〈0.01）] and those in PTX-intervented mice （8.1±1.5） U/ml and （7.8±1.5）U/ml, P〈0.01];The relative CYP2E1 positive cells in liver tissues in mice with acute and chronic alcoholic liver injury were （765±21） and （682±25）,respectively,significantly higher than those in normal controls （308±12） and （305±18）,P〈0.01）] and in mice with high-dosage of PTX intervention （521±18） and （418±12）,respectively,P〈0.01];The mRNA levels of ADH in liver tissues of mice with acute and chronic alcoholic liver injury were simi-lar to that in the controls, however, the relative CYP2E1 mRNA levels（1.47±0.32） and （1.13±0.52）] were sig-nificantly higher than those in normal controls （0.89±0.23） and （0.45±0.28）,respectively,P〈0.01）] and in mice with high-dose of PTX（0.92±0.27） and（0.48±0.32）,respectively,P〈0.01）];PPAR-α mRNA levels in liver tissues did not differ among mice with acute liver injury and normal controls,however,it was significantly lower than that in normal controls （0.85±0.21） in liver of mice with chronic alcoholic liver injury （0.45±0.31）,P〈0.05];The PPAR-α positive cells in mice of acute and chronic alcohol injury were（322±15） and（262±23）,respectively,sig-nificantly higher than those in normal controls （721±18）and （689±14）,P〈0.01] and in mice with high-dose of PTX intervention（548±20） and （725±19）,P〈0.01]. Conclusion PTX attenuates acute or chronic alcoholic liver injury,probably by through up-regulation of CYP2E1 and down-regulation of PPAR-α.