Progesterone receptors in the cerebral cortex of neonatal female rats.
Progestin-binding components were detected in cerebral cortical cytosols from female rats at 7 days of age. These components labeled in vitro with a tritiated synthetic progestin. R5020, sediment in the 7S region in sucrose density gradients containing 10% glycerol. The dissociation constants and the number of binding sites of the components were 3.9 X 10(-10)M and 47.5 fmol/mg cytosol protein, respectively, indicating high affinity and low capacity binding. The 7S-binding components were specific for progestational compounds. Estradiol competed weakly. Incubation with pronase abolished the 7S progestin binding. Heat experiments suggested a thermolabile nature of the components. These results suggest that the cytosols from the cerebral cortex of 7-day-old female rats contain progesterone receptors.
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D002540:Cerebral Cortex / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004355:Drug Stability; D004958:Estradiol / Q000378:metabolism; D006358:Hot Temperature; D066298:In Vitro Techniques; D011397:Promegestone / Q000378:metabolism; D011402:Pronase / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*
D011980:Receptors, Progesterone; D004958:Estradiol; D011397:Promegestone; D011402:Pronase