Aromatization and 19-hydroxylation of androgens by rat brain cytochrome P-450.
The oxidative metabolism of androgens in the rat brain includes aromatization preceded by the requisite 19-hydroxylation. We have examined the transformation of [19-C3H3]androstenedione and [4-14C]testosterone by the semipurified cytochrome P-450 fraction of the rat brain. [19-C3H3]Androstenedione generated tritiated water and formic acid in a ratio of 8 to 1 indicating that 19-hydroxylation in the brain far exceeds that necessary for aromatization. This was confirmed by the results of the 14C-testosterone incubation in which the 14C labeled 19-hydroxy and 19-oxo derivatives which were isolated exceeded the yield of 14C-estrogens by several fold. Thus the rat brain has the capacity to form in situ 19-hydroxylated androgens which are not available to it from the circulation.
Miyairi
S
S
Rockefeller University, New York, NY 10021-6399.
Sugita
O
O
Sassa
S
S
Fishman
J
J
D000728:Androgens / Q000378:metabolism*; D000735:Androstenedione / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D001345:Autoradiography; D001921:Brain / Q000201:enzymology*; D002855:Chromatography, Thin Layer; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D006900:Hydroxylation; D008861:Microsomes / Q000201:enzymology; D051381:Rats; D013739:Testosterone / Q000378:metabolism
D000728:Androgens; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol; D003577:Cytochrome P-450 Enzyme System; D001141:Aromatase