19-Hydroxylation and aromatization of androgens in the developing rat brain.
Endocrinology
; 121(4): 1209-14, 1987 Oct.
Article
em En
| MEDLINE
| ID: mdl-3653024
ABSTRACT
Androgen aromatization in the human placenta proceeds through two successive hydroxylations at C-19, the products of which are then virtually completely converted to estrogens. In the neonatal rat brain, however, 19-hydroxylation has been shown to exceed significantly subsequent aromatization, suggesting that formation of 19-hydroxylated androgen metabolites might be important in brain differentiation in this species. Using [19-3H3]androstenedione, we found that the surplus activity of 19-hydroxylase relative to aromatase was independent of age, sex, and androgen substrate concentration, despite 100-fold differences in tissue aromatase activity during the course of development. In addition, the surplus 19-hydroxylation was not affected by several agents which otherwise decreased or increased the activity of the aromatase enzyme, including metyrapone, KCN, and cytochrome P-450 reductase, the latter indicating that the failure of the 19-hydroxylated products to proceed to aromatization was not due to a deficit of reducing equivalents. 19-Hydroxylation of androgens in the rat brain is a quantitatively significant metabolic pathway in this tissue, although present data do not confirm the existence of a steroid C-19 hydroxylase in the brain separate from that involved in aromatization.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
Aromatase
/
Androgênios
/
Animais Recém-Nascidos
Limite:
Animals
Idioma:
En
Revista:
Endocrinology
Ano de publicação:
1987
Tipo de documento:
Article