Johansson M K, Sanderson J T, Lund B-O
Department of Environmental Toxicology, Uppsala University, Norbyv. 18A, SE-752 36 Uppsala, Sweden.
Toxicol In Vitro. 2002 Apr;16(2):113-21. doi: 10.1016/s0887-2333(01)00111-4.
The formation of steroids in the H295R human adrenocortical carcinoma cell line was analysed by HPLC or RIA, and based on these data the apparent catalytic activities of CYP11A, CYP17, CYP21 and CYP11B1 in this cell line were calculated. The environmental pollutant 3-methylsulfonyl-DDE (3-MeSO2-DDE) and the cytochrome P450 (CYP) inhibitors ketoconazole, metyrapone and aminoglutethimide were studied for their effects on the steroid formation. Metyrapone (IC50) of 1 microM) and 3-MeSO2-DDE (10 microM: 66 +/- 10% of control) were found to inhibit the apparent CYP11B1 activity. Ketoconazole inhibited all enzymes examined with the greatest effects on CYP11B1 (IC50) of 2.5 microM). Aminoglutethimide was examined only for effects on CYP11A activity and was shown to inhibit pregnenolone formation (20 microM: 61 +/- 4% of control). The possibility of studying all CYP enzymes in the corticosteroidogenesis makes this cell line a valuable test system to examine effects of chemicals, such as suspected endocrine disruptors, on the human glucocorticoid hormone synthesis. The inhibition of cortisol formation by 3-MeSO2-DDE supports an interaction with the active site of CYP11B1, as previously reported in mouse adrenocortical Y1 cells. In mice, this interaction led to metabolic activation and a high adrenotoxicity of 3-MeSO2-DDE. Therefore studies on the adrenotoxicity of 3-MeSO2-DDE in humans are needed.
采用高效液相色谱法（HPLC）或放射免疫分析法（RIA）分析了H295R人肾上腺皮质癌细胞系中类固醇的形成，并基于这些数据计算了该细胞系中细胞色素P450 11A（CYP11A）、细胞色素P450 17（CYP17）、细胞色素P450 21（CYP21）和细胞色素P450 11B1（CYP11B1）的表观催化活性。研究了环境污染物3 - 甲基磺酰基 - DDE（3 - MeSO2 - DDE）以及细胞色素P450（CYP）抑制剂酮康唑、美替拉酮和氨鲁米特对类固醇形成的影响。发现美替拉酮（半数抑制浓度[IC50]为1微摩尔/升）和3 - MeSO2 - DDE（10微摩尔/升：为对照的66±10%）可抑制CYP11B1的表观活性。酮康唑对所有检测的酶均有抑制作用，对CYP11B1的抑制作用最强（IC50为2.5微摩尔/升）。仅研究了氨鲁米特对CYP11A活性的影响，结果表明其可抑制孕烯醇酮的形成（20微摩尔/升：为对照的61±4%）。能够在皮质类固醇生成过程中研究所有CYP酶，使得该细胞系成为一个有价值的测试系统，可用于检测化学物质（如疑似内分泌干扰物）对人类糖皮质激素合成的影响。3 - MeSO2 - DDE对皮质醇形成的抑制作用支持了其与CYP11B1活性位点的相互作用，正如先前在小鼠肾上腺皮质Y1细胞中所报道的那样。在小鼠中，这种相互作用导致了3 - MeSO2 - DDE的代谢活化和高肾上腺毒性。因此，需要对3 - MeSO2 - DDE对人类的肾上腺毒性进行研究。
