非洲鲶鱼（Clarias gariepinus）大脑中芳香化酶活性的测定——两种检测方法的比较

Measurement of aromatase activity in the brain of the African catfish, Clarias gariepinus--a comparison of two assay methods.

作者信息

Timmers R J, Lambert J G

机构信息

Department of Experimental Zoology, University of Utrecht, The Netherlands.

出版信息

Comp Biochem Physiol B. 1987;88(2):453-6. doi: 10.1016/0305-0491(87)90325-7.

DOI:10.1016/0305-0491(87)90325-7

PMID:3427894

Abstract

In the brain of the African catfish aromatase activity was demonstrated with two different methods using [7-3H]androstenedione and [19-3H]androstenedione as substrates. Kinetic analysis of estrogen formation following incubations of a cell-free fraction of brain homogenates showed that the apparent Km is the same for both substrates (0.03 micro M), but the Vmax is smaller with [19-3H]androstenedione as substrate. This indicates a so-called isotope effect. A time course study showed that after an incubation of 4 hr the aromatase activity is still linearly time dependent. Comparing the amount of estrogens formed from both precursors showed that the value of the isotope effect is 3.4 Incubation of symmetric punches of telencephalon and diencephalon with the two substrates likewise showed an isotope effect of 3.4

摘要

在非洲鲶鱼的大脑中，使用[7-³H]雄烯二酮和[19-³H]雄烯二酮作为底物，通过两种不同方法证明了芳香化酶活性。对脑匀浆无细胞部分孵育后雌激素生成的动力学分析表明，两种底物的表观Km相同（0.03微摩尔），但以[19-³H]雄烯二酮作为底物时Vmax较小。这表明存在所谓的同位素效应。一项时间进程研究表明，孵育4小时后，芳香化酶活性仍与时间呈线性相关。比较由两种前体生成的雌激素量表明，同位素效应值为3.4。用这两种底物对端脑和间脑的对称切片进行孵育，同样显示出3.4的同位素效应。