Disposition of [4-14C]oestradiol-17 beta in the isolated perfused brain of the rat.

ABSTRACT

[4-14C] Oestradiol-17 beta was perfused through isolated brains of male and ovariectomized female rats. Two different perfusion media were used. The uptake of oestradiol-17 beta was higher in female brains, the highest concentrations being found in the hypophysis and hypothalamus. Oestradiol-17 beta was metabolized to a greater extent by female brains, the most important metabolite being oestrone. Additionally, 2-hydroxyoestradiol-17 beta, 6 zeta-hydroxyoestradiol-17 beta, and 7 alpha-hydroxyoestradiol-17 beta were found; 7 alpha-hydroxyoestrone and another polar metabolite could not be definitely identified. Quantitatively, 2-hydroxylation was no more important than hydroxylation at C atom 6 or 7.