Target cells for dihydrotestosterone in the guinea pig pituitary gland

Adult male guinea pigs were castrated and 24 h later injected with [3H]dihydrotestosterone. Their pituitary glands were then processed for autoradiographic and immunocytochemical analyses. Three percent of the parenchymal cells in the pars distalis were radiolabelled. These cells were primarily gonadotrophs; a small population of thyrotrophs were also found to retain the [3H]androgen. Labelling occurred in cells of the pars intermedia (3.2%) as well as in 9.6% of the pituicytes. These data indicate that in addition to gonadotrophs, the pars nervosa is a major target for dihydrotestosterone in the guinea pig pituitary gland.