Aryl hydrocarbon hydroxylase induction in mammalian liver-derived cell cultures. Stimulation of "cytochrome P1-450-associated" enzyme activity by many inducing compounds.
Aryl hydrocarbon hydroxylase induction in mammalian liver-derived cell cultures. Stimulation of "cytochrome P1-450-associated" enzyme activity by many inducing compounds.
复制标题
哺乳动物肝源性细胞培养物中芳基烃羟化酶的诱导。
作者：
I. Owens;D. Nebert
当用生长培养基中大量疏水化合物中的任何一种处理细胞时，在胎鼠肝原代培养物和源自大鼠肝癌H-35或小鼠肝癌BW 7756的细胞系中发现芳烃（苯并[a]芘）羟化酶活性增加。作为有效诱导剂的化合物包括3-甲基胆蒽、苯巴比妥钠、异丙肾上腺素、α-萘酮、β-萘酮、2，5-二苯基恶唑、2-（49-氯苯基）苯并噻唑，2-（49-甲酰基苯基）苯并噻唑，甲吡酮，1-（2-异丙基苯基）咪唑，2-二乙基氨基乙基-2，2-二苯基戊酸酯HCl（SKF 525-A）、胡椒基丁醚、己烯雌酚、月桂酸钠、烯丙基异丙基乙酰胺、苯胺和氨基比林。无论使用哪种诱导剂，在肝或肝癌来源的细胞培养物中发现的羟化酶活性似乎（a）在体外对α-萘醌或2，5-二苯基恶唑等抑制剂特别敏感，（B）在体外受甲吡酮或SKF 525-A等药物的抑制较小，（c）与还原型血蛋白-CO复合物的Soret峰的蓝色光谱位移有关。因此，对照培养物中的羟化酶活性和苯巴比妥在肝或肝癌衍生细胞培养物中诱导的羟化酶活性不同于对照和苯巴比妥处理的完整动物中的肝酶活性;我们的研究结果可能表明细胞色素P1450是由对照培养基中的某些因子或培养物中的苯巴比妥诱导的，而其他P450种类在对照或苯巴比妥处理的成年完整动物中占优势。已知某些化合物通过P1450与通过P450的代谢不同。对于肝或肝癌衍生培养物的研究，以及关于已知通过单加氧酶代谢途径代谢的某些化合物的细胞毒性、药物代谢或化学致癌性评价的研究，我们因此建议谨慎将培养细胞中发现的某些结果外推至完整动物中存在的实际情况。
Increases in aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity are found in fetal rat liver primary cultures and in cell lines derived from rat Reuber Hepatoma H-35 or mouse Hepatoma BW 7756, when the cells are treated with any one of a large number of hydrophobic compounds in the growth medium. Compounds which are effective inducers include 3-methylcholanthrene, sodium phenobarbital, isoproterenol, α-naphthoflavone, β-naphthoflavone, 2,5-diphenyloxazole, 2-(49-chlorophenyl)benzothiazole, 2-(49-formylphenyl)benzothiazole, metyrapone, 1-(2-isopropylphenyl)imidazole, 2-diethylaminoethyl-2,2-diphenyl valerate HCl (SKF 525-A), piperonyl butoxide, diethylstilbestrol, sodium laurate, allylisopropylacetamide, aniline, and aminopyrine. Regardless of which inducer is used, the hydroxylase activity found in liver- or hepatoma-derived cell cultures seems to be (a) particularly sensitive to such inhibitors in vitro as α-naphthoflavone or 2,5-diphenyloxazole, (b) less inhibited in vitro by such drugs as metyrapone or SKF 525-A, and (c) associated with a blue spectral shift in the Soret peak of the reduced hemoprotein-CO complex. The hydroxylase activity in control cultures and the hydroxylase activity induced by phenobarbital in liver- or hepatoma-derived cell cultures thus differ from the hepatic enzyme activities in the control and phenobarbital-treated intact animal; our findings presumably indicate that cytochrome P1450 is induced by some factor in the control medium or by phenobarbital in culture, whereas other P450 species predominate in the control or phenobarbital-treated adult intact animal. Certain compounds are known to be metabolized differently by P1450 than by P450. For studies with liver- or hepatoma-derived cultures and concerning evaluation of cytotoxicity, drug metabolism, or chemical carcinogenesis by certain compounds known to be metabolized via the monooxygenase metabolic pathways, we therefore suggest caution in the extrapolation of certain results found in cultured cells to the actual situation existing in the intact animal.