ABSTRACT
The effects of the polypeptide hormone prolactin (PRL) in the development and regulation of benign prostate hyperplasia (BPH) and also in prostate cancer are not very well characterized. This study examines the action of PRL, either alone or in association with androgens [testosterone (T) or dihydrotestosterone (DHT)], in the rat prostate gland. The effects of PRL and androgens were investigated after 30 and 60 days in control, castrated, castrated with a substitutive implant of T or DHT, and sham-operated Wistar rats. To enhance PRL release, we induced hyperprolactinemia by administering chronic injections of sulpiride (40 mg. kg(-1). day(-1)). Chronic hyperprolactinemia induces enlargement and inflammation of the lateral rat prostate without any histological changes on ventral and dorsal lobes. We also demonstrate that hyperprolactinemia induces Bcl-2 overexpression in the lateral rat prostate and that this could inhibit the level of apoptosis. The in vivo model established here is a useful in vivo approach for studying the hormonal regulation of normal and pathological prostate development.
Subject(s)
Gonadal Steroid Hormones/pharmacology , Hyperprolactinemia/pathology , Prostate/growth & development , Prostate/pathology , Testosterone/pharmacology , Animals , Apoptosis/drug effects , Apoptosis/physiology , Chronic Disease , Dihydrotestosterone/blood , Dihydrotestosterone/pharmacology , Dopamine Antagonists/pharmacology , Gonadal Steroid Hormones/blood , Hyperprolactinemia/chemically induced , Male , Orchiectomy , Organ Size , Prolactin/blood , Prostate/metabolism , Prostatic Hyperplasia/chemically induced , Prostatic Hyperplasia/pathology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Rats , Rats, Wistar , Sulpiride/pharmacology , Testosterone/bloodABSTRACT
The effect of the lipidosterolic extract of Serenoa repens (LSESR) on experimental prostate enlargement was investigated in three groups of rats: shams treated with LSESR (sham rats), castrated animals treated with estradiol and testosterone (castrated rats), castrated animals treated with estradiol/testosterone and treated with LSESR (castrated and treated rats). Following three months of continuous hormonal treatment, the weight of prostates in estradiol/testosterone-treated castrated rats was significantly increased in comparison with sham-operated rats. Such an increase started rapidly, reached a maximum by 30 days and remained at a plateau or slightly declined thereafter. The increase of prostate total weight induced by the hormone treatment was inhibited by administration of LSESR. Indeed, the weight was significantly lower at day 60 and day 90 for the dorsal and lateral regions of the prostate. The weight of the ventral region of the prostate was significantly lower after 30 and 60 days treatment with LSESR. These results demonstrate that administering LSESR to hormone-treated castrated rats inhibits the increase in prostate wet weight. This effect of LSESR may explain the beneficial effect of this extract in human benign prostatic hypertrophy.
