Glucocorticoid receptors in thymocytes of fetus, newborn, and adult CBA mice.

[3H]Dexamethasone binding was studied in vitro in cell suspensions of thymus from fetal and newborn mice. The number of glucocorticoid receptors appeared to be identical in fetal, newborn, and adult CBA mice. The affinities of these receptors, calculated by Scatchard analysis, were similar in the three groups of animals. The extent of in vitro steroid-induced inhibition of [3H]uridine incorporation by fetal and adult thymocyte suspensions was very similar. These results suggest that no significant variations in glucocorticoid receptors occur in thymic tissue during the neonatal period.