Effects of hyperprolactinemia on rat prostate growth: evidence of androgeno-dependence

The effects of the polypeptide hormone prolactin (PRL) in the development a nd regulation of benign prostate hyperplasia (BPH) and also in prostate can cer are not very well characterized. This study examines the action of PRL, either alone or in association with androgens [testosterone (T) or dihydro testosterone (DHT)], in the rat prostate gland. The effects of PRL and andr ogens were investigated after 30 and 60 days in control, castrated, castrat ed with a substitutive implant of T or DHT, and sham-operated Wistar rats. To enhance PRL release, we induced hyperprolactinemia by administering chro nic injections of sulpiride (40 mg.kg(-1).day(-1)). Chronic hyperprolactine mia induces enlargement and inflammation of the lateral rat prostate withou t any histological changes on ventral and dorsal lobes. We also demonstrate that hyperprolactinemia induces Bcl-2 overexpression in the lateral rat pr ostate and that this could inhibit the level of apoptosis. The in vivo mode l established here is a useful in vivo approach for studying the hormonal r egulation of normal and pathological prostate development.