TY  - JOUR
PY  - 1990//
TI  - The constitutive 7-ethoxycoumarin 0-deethylase of human placental microsomes: relationship to the intermediary steps in steroid aromatization
JO  - Life Sciences
A1  - Meigs, R. A.
SP  - 321
EP  - 327
VL  - 46
IS  - 5
N2  - All oxidative functions of aromatase, i.e., estrogen production, 19-oxygenated androgen production and 7-ethoxycoumarin deethylation, were inhibited in parallel in placental microsomes from non-smokers by the mechanism-based, time-dependent inactivators (suicide substrates) 10 beta-(2-propynyl)estr-4-ene-3,17-dione and 4-hydroxyandrost-4-ene-3,17-dione. In contrast, the aromatase suicide substrate androst-4-ene-3,6,17-trione had little or no effect on the conversion of androst-4-ene-3,17-dione to 19-hydroxyandrost-4-ene-3,17-dione or on the conversion of the latter to 3,17-dioxoandrost-4-en-19-al while severely limiting the capacity for estrogen production from androst-4-ene-3,17-dione and 19-hydroxyandrost-4-ene-3,17-dione in such microsomal preparations. Androst-4-ene-3,6,17-trione, therefore, appears to uncouple the 19-hydroxylation of androgens from estrogen synthesis. This agent also produced only a minimal inhibition of 7-ethoxycoumarin deethylation, indicating that this major constitutive transformation of a xenobiotic chemical is associated with the steroid 19-hydroxylating function of the aromatase system.<p /> <p>Language: en</p>
LA  - en
SN  - 0024-3205
UR  - http://dx.doi.org/10.1016/0024-3205(90)90010-o
ID  - ref1
ER  -