Androgen receptor systems in the brain stem of the primate.

The nuclear uptake and retention of [3H]dihydrotestosterone ([3H]DHT) or one of its metabolites was studied in the cerebellum and brain stem of the rhesus monkey. Three days before the injection of the tritiated hormone, we removed both ovaries and the right adrenal gland of 3 female rhesus monkeys under ketamine and halothane or fluothane anesthesia with aseptic surgical procedures. Two days later, we removed the left adrenal gland under similar conditions. Shortly after the second operation, each animal received 100 mg prednisolone sodium succinate. On the day of autopsy, we injected into a femoral vein of each animal 1 microgram of 5 alpha-dihydro[1,2,4,5,6,7-3H]-testosterone (107 Ci/mmol). One of these animals also received an i.v. injection of 100 micrograms/kg body weight of unlabeled DHT to serve as a control. One hour after injection, we rapidly exsanguinated each animal through a femoral venous catheter and perfused the vascular system with approximately 3 1 of Ringer's solution through a femoral arterial catheter. The cerebella and brain stems were removed and processed for autoradiography. Unlike in the rat, nuclear uptake and retention of [3H]DHT was found in both motor and sensory systems of these monkeys and in other areas less well defined. These data indicate that there are major species differences in the nuclear uptake and retention of androgen by the cerebellum and brain stem of rats and primates.