In vitro metabolism of androgens in hypothalamus and pituitary from infantile and adolescent rats of both sexes.

The metabolism of [3H]testosterone, [3H]dihydrotestosterone and [3H]. 5alpha-androstan-3beta, 17beta-diol was studied in vitro in pituitaries and hypothalami of male and female rats aged 5, 10, 15, 23, 30, 40 and 60 days. The concentration of labelled androgens in incubation medium was 10-20 nmol l-1. The metabolites were extracted from the medium with organic solvents and separated with the aid of thin-layer chromatography. Quantitative estimation of dihydrostestosterone, 5alpha-androstan-3alpha, 17beta-diol and of polar metabolites was made. It was found that: 1. only polar metabolites are formed from 5alpha-androstan-3beta, 17beta-diol in all age groups of both sexes; 2. in both sexes the metabolism of androgens in both tissues between 5 and 23 days of age was twice as high as that in adult ones; 3. sexual differences in the metabolism of androgens were found in all age groups investigated, although all androgens studied were not affected in each case; 4. most remarkable intersexual differences were found in both studied at 23 days of age. It may be suggested that androgens apparently play an important role in the hypothalamus and pituitary of both sexes during the early postnatal ontogenesis which is apparently related to the active metabolism of these steroids in these organs.