人肝脏中苯并芘羟化酶的特性及其与大鼠、兔子和豚鼠酶的比较。

Properties of benzpyrene hydroxylase from human liver and comparison with the rat, rabbit and guinea-pig enzymes.

Pelkonen O, Kaltiala E H, Kärki N T, Jalonen K, Pyörälä K

Xenobiotica. 1975 Aug;5(8):501-9. doi: 10.3109/00498257509056120.

Abstract

Benzpyrene hydroxylase of human liver biopsies and of livers from four inbred rat strains and from a non-inbred Sprague-Dawley rat strain, rabbit and guinea-pig was studied. 2. The human liver benzpyrene hydroxylase was similar to that of laboratory animals with respect to cofactor requirements, NADPH and O2, microsomal localization and inhibition by CO and N2. 3. Kinetic analysis of human adult benzpyrene hydroxylase indicated the presence of two enzymes, whereas human foetal liver contained only one enzyme hydroxylating 3,4-benzpyrene. Michaelis constants of human liver benzpyrene hydroxylase were slightly higher than Km values of animal liver enzymes. 4. Benzpyrene hydroxylase activity in human liver showed no sex difference, was enhanced by cigarette smoking and was decreased in patients with liver damage. 5. Variation of benzpyrene hydroxylase activity in human liver samples was about 6-fold in the 'control' group and 16-fold when all patients were considered. Variation of benzpyrene hydroxylase activity in inbred rat strains was less than 60% between different individuals and in the non-inbred rat, rabbit and guinea-pig the variation was 2- to 3-fold or less.

摘要

对取自人类肝脏活检样本以及四种近交系大鼠品系、一个非近交系斯普拉格-道利大鼠品系、兔子和豚鼠肝脏中的苯并芘羟化酶进行了研究。2. 人类肝脏苯并芘羟化酶在辅因子需求（NADPH和O2）、微粒体定位以及对CO和N2的抑制方面与实验动物的相似。3. 对人类成人苯并芘羟化酶的动力学分析表明存在两种酶，而人类胎儿肝脏仅含有一种使3,4-苯并芘羟化的酶。人类肝脏苯并芘羟化酶的米氏常数略高于动物肝脏酶的Km值。4. 人类肝脏中的苯并芘羟化酶活性无性别差异，吸烟会使其增强，而在肝脏损伤患者中则降低。5. 在“对照组”中，人类肝脏样本中苯并芘羟化酶活性的变化约为6倍，若考虑所有患者则为16倍。近交系大鼠品系中苯并芘羟化酶活性在不同个体间的变化小于60%，在非近交系大鼠、兔子和豚鼠中，该变化为2至3倍或更小。