Pathiratne A, Puyear R L, Brammer J D
Toxicol Appl Pharmacol. 1986 Feb;82(2):272-80. doi: 10.1016/0041-008x(86)90202-4.
Male Sprague-Dawley rats were injected ip with benzene, toluene, or a mixture of xylene isomers at 20 mmol hydrocarbon/kg daily for 3 days. The effects of administration of these hydrocarbons upon their own in vitro metabolism, as well as upon cytochrome P-450, NADPH-cytochrome c reductase, aminopyrine N-demethylase, aniline hydroxylase, glutathione, glutathione S-transferase, and UDPglucuronyltransferase in liver were studied. Each hydrocarbon studied increased its own in vitro metabolism. Benzene had no effect on the metabolism of toluene or xylenes. Toluene and xylenes increased the metabolism of benzene, toluene, and xylenes. Cytochrome P-450 was elevated by toluene and xylenes, but was not affected by benzene. NADPH-cytochrome c reductase was induced by all three hydrocarbons. Aminopyrine N-demethylase and aniline hydroxylase were induced by toluene and xylenes and were not affected by benzene. Glutathione was elevated by benzene, decreased by xylenes, and not affected by toluene. Glutathione S-transferase was induced differentially by these hydrocarbons toward various substrates: toward 1-chloro-2,4-dinitrobenzene by benzene and toluene, toward 1,2-dichloro-4-nitrobenzene by benzene and xylenes, and no effect toward 1,2-epoxy-3-(p-nitrophenoxy)propane by any hydrocarbons. UDPglucuronyltransferase was induced by benzene and toluene when o-aminophenol and phenol were used as the substrate. Xylenes had no effect. Benzene was more effective at inducing conjugation enzymes. Xylenes were more effective at inducing cytochrome P-450 dependent enzymes. Toluene was equipotent at inducing both types of enzymes. The results indicate that the addition of methyl groups to the aromatic ring affects the inductive pattern of these monocyclic aromatic hydrocarbons.
将雄性斯普拉格-道利大鼠腹腔注射苯、甲苯或二甲苯异构体混合物，剂量为每天20毫摩尔烃/千克，持续3天。研究了这些碳氢化合物给药对其自身体外代谢以及肝脏中细胞色素P-450、NADPH-细胞色素c还原酶、氨基比林N-脱甲基酶、苯胺羟化酶、谷胱甘肽、谷胱甘肽S-转移酶和UDP-葡萄糖醛酸基转移酶的影响。所研究的每种碳氢化合物都增加了其自身的体外代谢。苯对甲苯或二甲苯的代谢没有影响。甲苯和二甲苯增加了苯、甲苯和二甲苯的代谢。甲苯和二甲苯使细胞色素P-450升高，但不受苯的影响。NADPH-细胞色素c还原酶被所有三种碳氢化合物诱导。氨基比林N-脱甲基酶和苯胺羟化酶被甲苯和二甲苯诱导，不受苯的影响。苯使谷胱甘肽升高，二甲苯使其降低，甲苯对其没有影响。这些碳氢化合物对谷胱甘肽S-转移酶对不同底物的诱导作用不同：苯和甲苯对1-氯-2,4-二硝基苯有诱导作用，苯和二甲苯对1,2-二氯-4-硝基苯有诱导作用，对1,2-环氧-3-(对硝基苯氧基)丙烷任何碳氢化合物都没有影响。当以邻氨基酚和苯酚为底物时，苯和甲苯诱导UDP-葡萄糖醛酸基转移酶，二甲苯没有影响。苯在诱导结合酶方面更有效。二甲苯在诱导细胞色素P-450依赖性酶方面更有效。甲苯在诱导这两种酶方面效力相当。结果表明，在芳香环上添加甲基会影响这些单环芳香烃的诱导模式。
