Dihydrotestosterone regulation of thymocyte function in the rat mediation by serum factors.

We have previously reported that reticuloepithelial cells of rat thymic tissue contain specific, high-affinity estrogen (E) and dihydrotestosterone (DHT) receptors which are not present in thymocytes, and that stimulation of the concanavalin A (Con A) sensitive thymocyte population is by means of a thymic serum substance depressed by estradiol. To ascertain if a serum substance modulated by DHT could also effect a thymocyte population, we incubated thymocytes in vitro for 3 days in the presence of the mitogens Con A or phytohaemagglutinin (PHA) + tissue culture media + 20% specific rat serum preparations and pulse labelled with tritiated thymidine. Rat serum samples were prepared from control, castrate, thymectomized (Tx) and castrate-Tx animals as well as from similar groups of animals treated in vitro for 3 days with physiological doses of DHT.

Characteristics of the cytoplasmic and nuclear dihydrotestosterone receptors of human thymic tissue.

Dihydrotestosterone receptor was prepared from both the cytoplasm and nucleus of human thymic tissue. Human cytoplasmic and nuclear dihydrotestosterone receptor possessed a KA greater than 1.0 and by competition assay was highly specific for dihydrotestosterone.

Estradiol regulation of thymic lymphocyte function in the rat: mediation by serum thymic factors.

Estradiol (E2) can depress the function of the thymic lymphocytes. To determine if this response to a gonadal steroid is regulated directly or indirectly, thymic lymphocytes were incubated in vitro for 3 days in the presence of the mitogens concanavalin A (Con A) or phytohaemagglutinin (PHA) + tissue culture media + 20% specific rat serum fractions and pulse labelled with tritiated thymidine. Rat serum fractions were prepared from control, castrate, thymectomized (Tx) and castrate-Tx animals as well as from similar groups of animals treated in vivo for three days with physiological doses of E2.