ON MECHANISM OF ANDROGEN STERILIZATION

Spayed rats with and without early postnatal androgen treatment were injected with a small dose of tritium-labelled oestradiol and the radioactivity of various parts of the hypothalamus, parietal cortex, anterior pituitary, and uterus was measured. The anterior pituitary and uterus contained more radioactivity than the different parts of the brain investigated. The radioactivity in the anterior and middle hypothalamus was significantly higher than in the posterior hypothalamus and parietal cortex. The oestradiol-binding capacity of the anterior and middle hypothalamus and of the non-ncural target tissues was significantly reduced in the androgen-sterilized rats. The finding suggest that early postnatal androgen administration blocks the oestrogcn-receptor sites both in neural and non-neural target tissues. © 1969 S. Karger AG, Basel.