Nuclear RNA content and synthesis in anterior pituitary in intact, castrated and androgen sterilized rats

The content and uridine incorporation into nuclear RNA of anterior pituitary gland was studied in vitro in intact, castrated and neonatally testosterone treated rats of both sexes. In female rats a higher RNA content and a lower uridine incorporation rate could be observed than in males. The castration resulted in a marked increase of RNA content and uridine incorporation in male rats. Ovariectomy was followed by a decrease of RNA content which was accompanied by an increase of incorporation rate. Estradiol administration produced a biphasic change of RNA content and uridine incorporation in ovariectomized rats. From these findings a repressive action of estrogens on the nuclear RNA synthesis may be suggested. Neonatal testosterone treatment resulted in alterations of RNA synthesis which could be observed in both sexes.