CATECHOL ESTROGEN FORMATION BY THE HUMAN FETAL BRAIN AND PITUITARY

Abstract

Homogenates of central neuroendocrine tissues from 2 male and 1 female midtrimester fetuses were incubated with [2³H] estradiol-17β. Metabolism at the C-2 position was monitored by measuring the tritium incorporated into water in the incubate. Liberation of tritium from the substrate by hypothalamus, limbic tissues, parietal cortex and pituitary occurred to the extent of 5.1 – 12.7%, 1.6 – 8.5%, 4.7 – 10.8%, and 0.9 – 4.1% of starting radioactivity, respectively. The nature of the product was confirmed by the isolation of ¹⁴C labelled 2-hydroxyestrone derivative from separate incubations with ¹⁴C-estrone as the substrate. With or without correction for weight of tissue incubated, catechol estrogen formation under these conditions occurs at levels similar to those seen in rat brain homogenates except that in contrast to the rat, the human cortex is also highly active.