[Dependence on androgen metabolism in the hypophysis and hypothalamus on age in rats].

The in vitro metabolism of 3H-testosterone, 3H-dihydrotestosterone, 3H-5 alpha-androstan-3 alpha, 17 beta-diol and 3H-5 alpha-androstan-3 beta, 17 beta-diol was studied in hypophyses and hypothalamuses of the rats at the age from 5 to 60 days. The androgen metabolites were separated by means of chromatography in thin layers of silicogel. The rate of androgen metabolism in the organs studied from the 5th till the 23rd day of development was dozens of times that in the adult animals. Sexual dimorphism was also shown. 3H-5 alpha-androstan-3 beta, 17 beta-diol transforms in hypothalamuses and hypophyses of the rats of all age groups of both sexes into polar metabolites only. A suggestion is put forward to the effect that the extensive metabolism of androgens in the brain until the 23rd day of development is due to the development of the system hypothalamus-hypophysis-gonads, depends on the concentration of androgens circulating in the blood and is directed to control the secretion of gonadotropins. The above period of development is termed as "critical".