胎儿和成人肝脏中的胞质环氧化物水解酶

Cytosolic epoxide hydrolase in fetal and adult human liver.

作者信息

Pacifici G M, Colizzi C, Giuliani L, Rane A

出版信息

Arch Toxicol. 1983 Dec;54(4):331-41. doi: 10.1007/BF01234486.

Abstract

The epoxide hydrolase and glutathione S-transferase activity towards styrene oxide as substrate were investigated and compared in fetal and adult human liver cytosols. The rate of formation of styrene glycol from styrene oxide (nmole/min/mg protein) was 0.23 +/- 0.02 (means +/- SE; n = 10) in fetal and 0.83 +/- 0.05 (means +/- SE; n = 14) in adult liver specimens. The enzyme followed Michealis-Menten kinetics in the fetal liver. In adult liver specimens the enzyme showed biphasic kinetics. For comparative purposes, the cytosolic glutathione S-transferase activity was investigated in the cytosolic fractions from the same liver specimens. The fetal activity was 40% of the adult activity 3.9 +/- 0.50 (means +/- SE; n = 10) versus 9.94 +/- 1.75 (means +/- SE; n = 14) nmoles/min/mg protein.

摘要

研究并比较了胎儿和成人肝细胞溶质中以环氧苯乙烯为底物时环氧化物水解酶和谷胱甘肽S-转移酶的活性。胎儿肝脏中由环氧苯乙烯生成苯乙二醇的速率（纳摩尔/分钟/毫克蛋白质）为0.23±0.02（平均值±标准误；n = 10），成人肝脏标本中为0.83±0.05（平均值±标准误；n = 14）。该酶在胎儿肝脏中遵循米氏动力学。在成人肝脏标本中，该酶表现出双相动力学。为作比较，对相同肝脏标本的细胞溶质部分中的细胞溶质谷胱甘肽S-转移酶活性进行了研究。胎儿的活性为成人活性的40%，即3.9±0.50（平均值±标准误；n = 10）对9.94±1.75（平均值±标准误；n = 14）纳摩尔/分钟/毫克蛋白质。