Androgen receptors in the cerebral cortex of fetal female rhesus monkeys.

The present study characterizes putative androgen receptor activity in the cerebral cortex cytosol of the female fetal monkey (Macaca mulatta) on days 125-135 postconception. Binding activities were compared using tritiated 5 alpha-dihydrotestosterone (DHT) and methyltrienolone (R1881) as ligands. Receptor concentration and association constants (Ka) were estimated from bound/total vs. total ligand binding curves. For R1881 and DHT, Ka values were 4.3 X 10(9) and 7.0 X 10(9) M-1, respectively. Receptor concentrations using the two ligands were estimated to be 5.5 X 10(-15) mol/mg protein (R1881; n = 2) and 1.7 X 10(-15) mol/mg protein (DHT). Analysis of receptor binding on DEAE-cellulose columns (KCl gradient) revealed multiple binding peaks (0.05-0.3 M KCl); similar elution profiles were obtained for the two ligands. Competition with either R1881 or DHT significantly reduced [3H]DHT binding throughout the KCl gradient, while triamcinolone acetonide had no effect. In contrast, [3H]R1881 binding was reduced by all three competitors. Cytosol from fetal male seminal vesicles had [3H]ligand-binding activity that was chromatographically similar to that of cerebral cortex. In contrast, binding in fetal male serum was negligible. Competition of cerebral cortex binding with a variety of hormones, including SCH-16423, progesterone, and cortisol, and analysis of the results on DEAE-cellulose suggested that there may be additional species of ligand-binding molecules. In summary, the findings verify the existence of a specific androgen receptor(s) in the cerebral cortex of fetal female rhesus monkeys. Its presence may be important for understanding both the influence of androgens on central nervous system development and the potential for teratogenic agents to disrupt normal patterns of central nervous system development.