TY - JOUR
T1 - Age-dependent induction and repression of rat liver microsomal hydroxylase systems by estradiol
AU - Gustafsson, Jan Åke
AU - Ingelman-Sundberg, Magnus
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1974/7/4
Y1 - 1974/7/4
N2 - The activities of the hepatic microsomal 2α-, 2β-, 18- and 7α-hydroxylase systems active on 5α-[4-14C] androstane-3α,17β-diol were studied in male and female rats which had been castrated and spayed at 14, 24, 35 and 45 days of age, treated for 5 days with 500 μg of estradiol benzoate per kg body weight and killed 6 days after gonadectomy. The hepatic microsomal 15β-hydroxylase enzyme system active on 5α-[1,2-3H] androstane-3α, 17β-diol 3,17-disulphate was also measured in these animals as well as in an additional group of animals that were gonadectomized at 56 days of age, treated with estradiol benzoate and killed at 62 days of age. The hydroxylase systems active on the free steroid substrate were all relatively unresponsive towards enstradiol in the developing rat, in contrast to the strong effects on hepatic hydroxylase activities previously noted following treatment of adult male rats with estradiol. On the other hand, the 15β-hydroxylase system active on disulphurylated 5α-androstane-3α, 17β-diol was inducible in both male and female rats of 41 and 51 days of age and in male rats of 61 days of age.
AB - The activities of the hepatic microsomal 2α-, 2β-, 18- and 7α-hydroxylase systems active on 5α-[4-14C] androstane-3α,17β-diol were studied in male and female rats which had been castrated and spayed at 14, 24, 35 and 45 days of age, treated for 5 days with 500 μg of estradiol benzoate per kg body weight and killed 6 days after gonadectomy. The hepatic microsomal 15β-hydroxylase enzyme system active on 5α-[1,2-3H] androstane-3α, 17β-diol 3,17-disulphate was also measured in these animals as well as in an additional group of animals that were gonadectomized at 56 days of age, treated with estradiol benzoate and killed at 62 days of age. The hydroxylase systems active on the free steroid substrate were all relatively unresponsive towards enstradiol in the developing rat, in contrast to the strong effects on hepatic hydroxylase activities previously noted following treatment of adult male rats with estradiol. On the other hand, the 15β-hydroxylase system active on disulphurylated 5α-androstane-3α, 17β-diol was inducible in both male and female rats of 41 and 51 days of age and in male rats of 61 days of age.
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U2 - 10.1016/0304-4165(74)90003-8
DO - 10.1016/0304-4165(74)90003-8
M3 - Article
C2 - 4841344
AN - SCOPUS:0016206948
SN - 0304-4165
VL - 354
SP - 172
EP - 181
JO - BBA - General Subjects
JF - BBA - General Subjects
IS - 2
ER -