Characterization of a glucocorticoid receptor in neonatal rat mammary gland.
A glucocorticoid receptor has been identified in cytosolic fractions prepared from 4-day old female Sprague-Dawley rat mammary glands at an early resting stage of mammary development. This component sedimented at 10S and 5S on respectively low and high (0.4 M KCl) ionic strength gradients. It bound dexamethasone with a high affinity (Kd approximately 2-6 nM) and a low capacity (N = 300 +/- 100 fmol per mg of proteins or 3.3 +/- 1.3 fmol per micrograms DNA), with a hierarchy of affinity by competition studies dexamethasone greater than corticosterone greater than progesterone greater than R 5020 much greater than Estradiol-17 beta. The characteristics of this glucocorticoid-binding protein are thus very similar to the adult one isolated from adult rat mammary gland.
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001667:Binding, Competitive; D003345:Corticosterone / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D008321:Mammary Glands, Animal / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D011987:Receptors, Steroid; D011374:Progesterone; D004958:Estradiol; D003907:Dexamethasone; D003345:Corticosterone