Biosynthesis of immunoreactive inhibin-like material (IR-ILM) by rat prostate

Presence of biologically active inhibin-like material (ILM) in the rat prostate was demonstrated by suppression of in vitro follicle-stimulating hormone release from rat pituitaries, and its in vitro biosynthesis was studied by immunoprecipitation of 3H-leucine incorporated in ILM. In vitro biosynthesis of immunoreactive ILM (IR-ILM) was greater in prostate from castrated as compared to intact rats and it decreased in prostates from castrated rats treated with testosterone. In prostates from estrogen-treated castrated animals, an increase in IR-ILM synthesis was observed. These observations indicated that in addition to the testes prostate could be an additional source of ILM and that IR-ILM synthesis in prostate is modulated by hormones.