[Non-aromatizing androgen 19-hydroxylase in human fetal organs].
19-hydroxyandrostenedione (19-OH A), known for many years as an obligatory intermediate of estrogen biosynthesis, has recently been found to be an amplifier of aldosterone action and in itself a hypertensinogenic steroid (J. Steroid Biochem., 16; 329, 1982). To search the presence of a non-aromatizing andorgen 19-hydroxylase in fetal organs, metabolism of labeled androstenedione(A) in fetal adrenal, liver, lung, brain and kidney was studied. 19-hydroxylase activity was calculated by the amounts of 19-OH A formed from A. The tissue homogenate was incubated with [4-14C]A and NADPH for different periods of time under air. The product, [4-14C] 19-OH A with added carrier standard [6,7-3H] 19-OH A was separated and purified by TLC, acetylation and TLC to constant 3H/14C ratio. The identity of the product was established by C.C.D. and by GC-MS analysis of purified product 19-AcOA in a larger scale adrenal incubation of non-labeled A. 19-hydroxylase activity was 0.9 pmol/min/mg protein for adrenal, but there was a negligible quantity of 19-OH A in lung, brain and kidney. Estrogen production was also assayed by 3H-water method using [1 beta-3H, 4-14C] A (3H/14C = 69.9). No detectable amount of estrogen was found in incubation of any homogenate except for liver. These results indicate that the non-aromatizing 19-hydroxylase activity in fetal adrenal gland is much higher than that in other organs. This is the first report to demonstrate the presence of 19-hydroxylase in human fetal adrenal tissue. It is suggested that 19-OH A secreted from fetal adrenal may also be associated with serum concentration of fetal circulation.
Shimizu
Y
Y
Department of Obstetrics and Gynecology, School of Medicine, Showa University, Tokyo, Japan.
Kosaki
T
T
Hashino
M
M
Sugisaki
K
K
Yanaihara
T
T
Nakayama
T
T
Osawa
Y
Y
D000311:Adrenal Glands / Q000196:embryology / Q000201:enzymology* / Q000378:metabolism; D000735:Androstenedione / Q000031:analogs & derivatives* / Q000378:metabolism; D001141:Aromatase / Q000378:metabolism; D004967:Estrogens / Q000096:biosynthesis; D006801:Humans; D008099:Liver / Q000196:embryology / Q000201:enzymology* / Q000378:metabolism; D013250:Steroid Hydroxylases / Q000378:metabolism*
D004967:Estrogens; D000735:Androstenedione; C011482:19-hydroxy-4-androstene-3,17-dione; D013250:Steroid Hydroxylases; C027110:steroid 19-hydroxylase; D001141:Aromatase