Evidence for estradiol-induced differential expression of genes for brain RNA polymerase during developmental stages of the rat

In order to gain insight into the steroid hormone-induced differential expression of genes for several rate-limiting enzymes of various metabolic pathways during differentiation, growth, adulthood, and senescence in rats, nuclear RNA polymerase of the cerebellum and cerebral hemispheres were studied. The level of this enzyme in both the tissues was highest in the immature rats and decreased significantly thereafter with increasing age. Ovariectomy decreased, and estradiol administration increased significantly the activity of this enzyme in both cerebellum and cerebral hemispheres of immature, young-adult, adult, and late-adult rats but not of senescent rats. However, the effects of these treatments were highest in the young-adult rats.