EXPRESSION OF ANDROGEN RECEPTOR IN THE DEVELOPING RAT EPIDIDYMIS AND ITS REGULATION BY ANDROGENS

Epididymis depends upon androgens for itsprenatal and postnatal differentiation,absorptionof testicular fluid,transport of sperm,and secre-tion of proteins thatbring aboutfunctional changesin sperm1] .Because of the significance of andro-gens in epididymis- mediated sperm maturation,weassessed the localization,developmental patterns,and hormonal control of androgen receptors(AR)in the developing and ethane dimethane sulfonate(EDS) treated SD rat epididymis(caput,corpusand cauda) .The immuno…

EXPRESSION OF ANDROGEN RECEPTOR IN THE DEVELOPING RAT EPIDIDYMIS AND ITS REGULATION BY ANDROGENS

Objective To study the distribution, developmental patterns, and hormonal control of androgen re- ceptors(AR) in the developing and ethane dimethane sulfonate(EDS) treated male SD rat epididymis. Methods The ABC technique of immunohistochemistry and image analysis were used to assess optodensity means (OPTDM) of AR, providing a measure of relative nuclear AR concentration. Results The specific AR immunostaining was observed in the nuclei of epididymal epithelium, peritubular smooth muscle cells and intertubular connective tissue cells. The rela- tive AR concentrations varied with the different segments of the epididymis in the adult rat(P<0. 05 or P<0.01). AR protein was highest in the caput (0. 763--0. 026),lowest in the corpus (0. 712±0. 025) and intermediate in the cauda (0. 736±0. 008). Levels of epididymal AR changed with development. In the cauda, AR level was highest on day 21 (0. 773±0. 028),intermediate on day 35(0. 762±0. 022),and lowest on day 90～120(0. 736±0. 008). The 90～120d group was significantly different from the 21d group (P＜0. 01)and 35d group (P＜0. 05). After the adult rats were treated with EDS to eradicate Leydig cells and endogenous testosterone, it was observed that the OPTDM of AR in the epididymal cauda epithelium was significantly reduced (P＜0. 001), and was restored to the control level by using ex- ogenous testosterone replacement (P＜0. 001). Conclusion These results suggest that the epididymal corpus depends least on androgens and the AR expression in the epididymis decreases with age and is dependent on circulating andro- gens.