Estrogen Receptor α Has a Functional Role in the Mouse Rete Testis and Efferent Ductules1

Abstract

Previous studies of the estrogen receptor-alpha knockout (alpha ERKO) in the male mouse demonstrate that the rete testis and efferent ductules are targets of estrogen. Because the alpha ERKO mouse lacks a functional estrogen receptor alpha (ER alpha) throughout development, it was not known whether the morphological and physiological abnormalities observed in the alpha ERKO male were due to developmental defects or to dysfunctions concurrent with the lack of ER alpha in the tissue. This study was designed to determine if treatment of normal wild-type (WT) mice with the pure antiestrogen, ICI 182,780, (ICI) could reproduce the morphological characteristics seen in alpha ERKO mice. Thirty-day-old male mice were treated for 35 days with either castor oil or ICI. Age-equivalent alpha ERKO mice were used for comparison. Light microscopic examinations of the reproductive tracts revealed dramatic changes in the efferent ductules of treated mice: a 1.7-fold increase in luminal diameter, a 56% reduction in epithelial cell height, a 60% reduction in brush boarder height of nonciliated cells, and an apparent reduction of the number of observable lysosomes and endocytotic vesicles. Testes of ICI-treated mice showed swollen rete testes area (6.5 times larger than control) and a 65% reduction in rete testis epithelium height. However, there were no significant changes in body and testis weights. These results indicate that ER blockage with ICI in WT mice results in morphological changes of the efferent ductules resembling those seen in alpha ERKO siblings of the same age. Based on this study, we conclude that ER alpha has a functional role in the mouse reproductive tract and the aberrant morphology observed in the efferent ductules of the alpha ERKO mouse is likely the result of a concurrent response to the lack of functional ER alpha, and not solely due to the lack of ER alpha during early developmental times.

Morphological analysis of endocytosis in efferent ductules of estrogen receptor‐α knockout male mouse

“…In the ␣ERKO male efferent ductules, the nonciliated epithelial cells have a reduction in microvilli size and number, area of apical cytoplasm, and number of apical tubules, endosomes and lysosomes. This study confirms our previous reports with light microscopy showing reduction in epithelial height, endocytotic vesicles and PASϩ granules in the nonciliated cells of the ␣ERKO efferent ductules (Hess et al, 2000;Lee et al, 2000). It also extends these observations with immunohistochemical evaluations.…”

“…It has been known for several years that neonatal exposure to excessive estrogen induces al-1997). The function of estrogen in the male reproductive tract had been speculative until recently, however, when it was found that ER␣ functions in the adult efferent ductules to regulate fluid reabsorption from the lumen (Hess et al, 1997aLee et al, 2000).…”

“…In these animals, the epithelium of the efferent ductules is reduced in height. The cytoplasm of the nonciliated cells appears to have a reduced number of endocytotic organelles such as lysosomes that are numerous in a normal nonciliated cell (Hess et al, 1997aLee et al, 2000). Therefore, estrogen and ER␣ are assumed to play a major role in fluid reabsorption.…”

Analysis of Differential Expression of Cytochrome P450 Aromatase(Cyp19) in The Efferent Ductules and The Epididymis of Male Rats During Postnatal Development

“…Spermatozoa produced from the testis become mature and acquire fertilizing capacity throughout traveling the excurrent duct, the efferent ductules (EDs) and the epididymis. The EDs are tubular structure that has a lumen inside surrounded by a single layer of epithelia (Lee et al, 2000). The…”

Expression of Monocarboxylate Transporters(MCTs) and Basigin and Estrogen Receptor α(ERα)-Mediated Regulation of MCT1 Expression in The Efferent Ductules of Male Reproductive Tract During Postnatal Development

“…The nonciliated cells, a dominant cell type in the epithelium of the ED, are characterized by the presence of apical microvilli . These cells have distinct features which are specialized for the uptake of materials and fluid from the lumen ; Lee et al, 2000). The ciliated cells have apical cilia, protruding into lumen, and relatively high number of mitochondria .…”