[Relationship between androgenization and differentiation of hypothalamic centers].

Dependence of the sterilizing action of androgen on differentiation of the hypothalamic centers was studied during the postnatal development of female rats. Asynhronous differentiation in the development of the arcuate nucleus (tonic centre) and suprachiasmatic nucleus (cyclic centre) was observed. Neurocytes of the arcuate nucleus started to produce secretory granules in 20-day embryos, while in the suprachiasmatic nucleus the neurocytes with secretory granules appeared in 5--7-day rats. Injection of testosterone propionate induced an anovulatory cycle in females the first 7 days after birth; this is associated with the inhibition of development of the hypothalamic cyclic centre.