Steroidogenic enzyme systems in the rat adrenal glands during postnatal development.

Abstract The processes of steroid hormone biosynthesis in rat adrenal glands were studied in the early postnatal period. The hydroxylation of progesterone to corticosterone and Porter-Silber chromogens is lower in 16-day-old rats than in 5- or 30-day-old animals. The activity of the NADP-linked dehydrogenases, on the other hand, proved to be high in the same periods. The reduced pyridine nucleotide coenzyme content, however, was low. Thyroidectomy or castration does not change the production of steroid hormones by the adrenal gland until the third week of life. The repeated injections of ACTH increased the hydroxylation of progesterone-4- 14 C to corticosterone and 18-hydroxy-11-deoxycorticosterone by the adrenals of young rats, but this was not observed in adult animals. The adrenal weight was not increased in 16-day-old rats injected repeatedly with ACTH. However, in 8-day-old as well as in adult animals, a marked increase of adrenal weight was observed under the ACTH stimulation.