Stimulation of de novo synthesis of cytochrome P-450 by phenobarbital in primary nonproliferating cultures of adult rat hepatocytes.
Stimulation of de novo synthesis of cytochrome P-450 by phenobarbital in primary nonproliferating cultures of adult rat hepatocytes.
复制标题
在成年大鼠肝细胞的原代非增殖培养物中苯巴比妥刺激细胞色素 P-450 从头合成。
DOI：
10.1073/pnas.79.9.2922
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发表时间：
1982
影响因子：
11.1
通讯作者：
Guzelian,PS
中科院分区：
文献类型：
--
作者：
Newman,S;Guzelian,PS
从成年大鼠肝脏制备并维持在无血清培养基中的非增殖性实质细胞的原代单层培养物对苯巴比妥的添加有反应，细胞色素 P-450 蛋白的合成和积累呈浓度依赖性增加，在免疫化学和催化方面与用苯巴比妥处理的成年大鼠肝脏中发现的细胞色素 P-450 蛋白的合成和积累没有区别。当药物首次添加到不超过 24 小时的培养物中，然后在培养基中维持 96 小时时，苯巴比妥可最大程度地刺激该细胞色素蛋白的合成速率，比对照培养物高 20 倍（总细胞蛋白合成速率的 1.01%）。除了苯巴比妥之外，被归类为“苯巴比妥样”体内诱导剂的化学物质（美芬妥英、灭蚁灵、2,2',4,4',5,5'-六溴联苯）在培养物中诱导了这种相同免疫反应蛋白的合成。与单独接受苯巴比妥的培养物相比，在培养基中添加 0.1 µM H2SeO3 加苯巴比妥可使这种诱导型细胞色素蛋白的合成速率平均提高 2 倍。由于在标准培养基中维持超过24小时的肝细胞培养物中硒含量和硒酶谷胱甘肽过氧化物酶的活性下降，添加的硒似乎纠正了自发获得的细胞硒缺乏。与培养物中的肝细胞迅速去分化并普遍丧失细胞色素 P-450 等特殊功能的概念相反，我们的数据表明，苯巴比妥诱导形式的细胞色素 P-450 的表达在培养物中并未消失，而是被短暂掩盖，并随着细胞适应不完美的培养环境条件而减弱。
Primary monolayer cultures of nonproliferating parenchymal cells prepared from adult rat liver and maintained in serum-free medium responded to additions of phenobarbital with concentration-dependent increases in synthesis and accumulation of a cytochrome P-450 protein immunochemically and catalytically indistinguishable from that found in the livers of adult rats treated with phenobarbital. Maximal stimulation of the rate of synthesis of this cytochrome protein by phenobarbital, as much as 20-fold higher than in control cultures (1.01% of the rate of synthesis of total cellular protein), could be achieved when the drug was first added to cultures no older than 24 hr and then was maintained in the medium for 96 hr. In addition to phenobarbital, chemicals classified as "phenobarbital-like" inducers in vivo (mephenytoin, mirex, 2,2',4,4',5,5'-hexabromobiphenyl) induced synthesis in culture of this same immunoreactive protein. Supplementation of the medium with 0.1 microM H2SeO3 plus phenobarbital produced an average 2-fold enhancement in the rate of synthesis of this inducible cytochrome protein as compared to that in cultures receiving phenobarbital alone. Inasmuch as there was a decline in selenium content and in the activity of the seleno-enzyme glutathione peroxidase in hepatocyte cultures maintained in standard culture medium for more than 24 hr, the added selenium appears to correct a spontaneously acquired cellular deficiency in selenium. Contrary to the concept that liver cells placed in culture promptly dedifferentiate with general loss of specialized functions such as cytochrome P-450, our data demonstrate that expression of the phenobarbital-inducible form of cytochrome P-450 is not extinguished in culture, but rather it is masked transiently and is attenuated as the cells adapt to the imperfect conditions of the culture environment.