3-甲基胆蒽对大鼠肝细胞细胞色素P450 1A的诱导作用

目的　研究 3 甲基胆蒽 (3 methylcholanthrene,3 MC)对原代培养大鼠肝细胞细胞色素P450 1A(CYP 1A)酶活力的诱导作用 ,并探讨其时间 效应和剂量 效应关系。方法　原位 2步胶原酶灌流法分离大鼠肝细胞 ,无血清条件下培养细胞 ,并用不同剂量的 3 MC诱导肝细胞 2 4h或 48h。乙氧基试卤灵 (ethoxyresorufin,EOR)为CYP 1A酶活力探针药 ,高效液相色谱法 (HPLC)测定试卤灵 (resorufin,RSF)浓度。结果　实验条件下对照组和 3 MC诱导组的RSF均可被检测 ,与对照细胞相比 ,除 0 0 0 5μmol L的 3 MC对原代培养大鼠肝细胞EROD无显著诱导作用外 ,其余剂量 (0 0 5 ,0 5 ,5μmol L)的 3 MC均明显诱导酶活力 ,酶活力分别被上调至对照组的 5 0 8,2 3 3 ,33 6倍 (P <0 0 1 ) ,3 MC的诱导作用在 2 4h达最强 ,而其在 48h的诱导作用与 2 4h相似。3 MC对原代培养大鼠肝细胞CYP 1A酶活力的诱导作用呈明显的剂量依赖性。结论　 3 MC对大鼠原代培养肝细胞CYP 1A酶活力有明显的诱导作用

Inductive effects of 3-methylcholanthrene on cytochrome P450 1A enzyme activity in primary cultured rat hepatocytes

Objective To investigate the inductive effects of 3 methylcholanthrene (3 MC) on cytochrome P450 1A(CYP 1A)activity of rat hep atocytes in primary culture.Methods Rat hepatocytes were isolated by two-step in situ collagenase perfusion method;cells were treated with 3 MC at various concentra tions for 24 h or 48 h,respectively.To study the stability and inducibility of p rimary cultured rat hepatocytes,the deethylation of 7 ethoxyresorufin was measu red by high performance liquid chromatography (HPLC).Results Rat hepatocytes in primar y culture remained the ability to increase CYP 1A activity upon incubation with 3 MC.3 MC increase(5 to 34-fold over control) 7-ethoxyresorufin-O-de ethylase(EROD)activity.EROD activity was detected in both control and 3 MC trea ted cel ls.Conclusion 3 MC can induce CYP 1A in primary cultured rat hepatocy tes.Primary cultured rat hepatocytes can be a good model for the study of drug m etabolism,pharmacology and toxicology.