Abstract:
Estrogen is synthesized in the male reproductive system and is found in highconcentrations in rete testis and seminal fluids. This luminal estrogentargets estrogen receptors (ER) along the male reproductive tract, and inparticular the efferent ductules, where ERα is abundant. However,both ERα and ERβ are found in various regions of the malereproductive tract. The transgenic ER knockout mice (αERKO and‚ βERKO) have been used to help define the role of ER in themale. In the αERKO animal model, the efferent ductules aredramatically altered, forming an epithelium in which fluid reabsorption isinhibited and epithelial cells have greatly reduced numbers of lysosomes andorganelles associated with endocytosis. The βERKO male reproductivetract appears normal. Because these animals are transgenic and lack ERthroughout development, we developed animal models using pure antiestrogen ICI182,780 treatments in adult males. The data show that ERαparticipates in the regulation of the apical cytoplasm of non-ciliated cellsof the efferent ductules, narrow cells of initial segment epididymis and clearcells in the remaining segments of the epididymis. There appears to be noeffect on vas deferens. The inhibition of ERα function in the maleleads to decreases in sperm concentrations and eventually to infertility. Thecurrent literature leaves the mechanisms of estrogen action in the malereproductive tract unsettled and raises the question of androgen’scontribution to the regulation of fluid transport, especially in the efferentductules.Extra keywords: efferent ductules, estrogen receptor,male, testis.