Male rat brain androgen metabolism and sexual behavior

Four groups of male rats, previously treated for sexual behavior and differing in age and length of time following castration, were examined for the localization of (3H)-testosterone (T) and (3H)-5alpha-dihydrotestosterone (DHT) in the brain following the injection of (3H)-T. Significant differences existed in the concentration of the 2 androgens among brain regions in all groups. Only in the subcellular particulate fraction from the hypothalami of 1 group castrated for 48 h was there a significant correlation (r=-0.97) between DHT and T levels and pretest mating performance. Though the amount of DHT found in the pituitary was strongly affected by the length of time between castration and sacrifice, no similar effect was found in the brain.