2,4,4'-三氯-2'-羟基二苯醚对大鼠肝脏细胞色素P450酶的影响。

Effect of 2,4,4'-trichloro-2'-hydroxydiphenyl ether on cytochrome P450 enzymes in the rat liver.

作者信息

Hanioka N, Jinno H, Nishimura T, Ando M

机构信息

Division of Environmental Chemistry, National Institute of Health Sciences, Tokyo, Japan.

出版信息

Chemosphere. 1997 Feb;34(4):719-30. doi: 10.1016/s0045-6535(97)00464-5.

DOI:10.1016/s0045-6535(97)00464-5

PMID:9569940

Abstract

We examined the effect of 2,4,4'-trichloro-2'-hydroxydiphenyl ether (Irgasan DP300) on microsomal cytochrome P450 (P450) enzymes in rat liver. Rats were treated intraperitoneally with Irgasan DP300 daily for 4 days, at doses of 0.2, 0.4 and 0.8 mmol/kg. Among the P450-dependent monooxygenase activities, 7-benzyloxyresorufin O-debenzylase (BROD) and 7-pentoxyresorufin O-depentylase (PROD) in rats, which are associated with CYP2B1, were remarkably induced by all doses of Irgasan DP300. The relative induction to each control activity were from 5.6- to 22.3-fold and 4.9- to 20.2-fold, respectively. Furthermore, immunoblotting showed that CYP2B1/2 protein level in rat liver microsomes was increased from 10.8- to 34.4-fold by Irgasan DP300. In addition, 7-ethoxycoumarin O-deethylase (ECOD) and p-nitrophenol hydroxylase (PNPH) activities were significantly increased by Irgasan DP300 at all doses (from 1.4- to 4.9-fold). Although the activities of other P450-dependent monooxygenases, namely aminopyrine N-demethylase (APND), aniline p-hydroxylase (ANPH), erythromycin N-demethylase (EMND), lauric acid omega-hydroxylase (LAOH) and testosterone 6 beta-hydroxylase (TS6BH) were increased at high doses (> or = 0.4 mmol/kg) of Irgasan DP300, the relative level was lower than those of the CYP2B1-dependent monooxygenases such as BROD and PROD. However, 7-ethoxyresorufin O-deethylase (EROD), 7-methoxyresorufin O-demethylase (MROD), testosterone 2 alpha-hydroxylase (TS2AH) and testosterone 7 alpha-hydroxylase (TS7AH) activities were not affected by any doses of Irgsan DP300. Immunoblotting showed that CYP3A2/1 and CYP4A1 protein levels were significantly induced from 1.3- to 2.2-fold by Irgasan DP300 (> or = 0.4 mmol/kg), whereas those of CYP1A1/2, CYP2C11/6 and CYP2E1 were not affected by any doses of Irgasan DP300. These results suggest that Irgasan DP300 induces the P450 isoforms of CYP2B subfamily in the rat liver, and that the induced P450 isozymes closely relates to the toxicity of Irgasan DP300 or its chlorinated derivatives.

摘要

我们研究了2,4,4'-三氯-2'-羟基二苯醚（三氯生）对大鼠肝脏微粒体细胞色素P450（P450）酶的影响。大鼠连续4天每天腹腔注射三氯生，剂量分别为0.2、0.4和0.8 mmol/kg。在P450依赖的单加氧酶活性中，与CYP2B1相关的大鼠7-苄氧基试卤灵O-脱苄基酶（BROD）和7-戊氧基试卤灵O-脱戊基酶（PROD），均被所有剂量的三氯生显著诱导。相对于各对照活性的诱导倍数分别为5.6至22.3倍和4.9至20.2倍。此外，免疫印迹显示，三氯生使大鼠肝脏微粒体中CYP2B1/2蛋白水平提高了10.8至34.4倍。另外，所有剂量的三氯生均使7-乙氧基香豆素O-脱乙基酶（ECOD）和对硝基苯酚羟化酶（PNPH）活性显著增加（1.4至4.9倍）。虽然其他P450依赖的单加氧酶，即氨基比林N-脱甲基酶（APND）、苯胺对羟化酶（ANPH）、红霉素N-脱甲基酶（EMND）、月桂酸ω-羟化酶（LAOH）和睾酮6β-羟化酶（TS6BH）的活性在高剂量（≥0.4 mmol/kg）三氯生作用下有所增加，但其相对水平低于BROD和PROD等CYP2B1依赖的单加氧酶。然而，7-乙氧基试卤灵O-脱乙基酶（EROD）、7-甲氧基试卤灵O-脱甲基酶（MROD）、睾酮2α-羟化酶（TS2AH）和睾酮7α-羟化酶（TS7AH）的活性不受任何剂量三氯生的影响。免疫印迹显示，≥0.4 mmol/kg的三氯生使CYP3A2/1和CYP4A1蛋白水平显著诱导1.3至2.2倍，而CYP1A1/2、CYP2C11/6和CYP2E1的蛋白水平不受任何剂量三氯生的影响。这些结果表明，三氯生诱导大鼠肝脏中CYP2B亚家族的P450同工酶，且诱导的P450同工酶与三氯生或其氯化衍生物的毒性密切相关。