Expression of estrogen, progesterone and androgen receptors in the oviduct of developing, cycling and pre-implantation rats

Abstract

To determine expression and localization of receptors for estrogen (ER), progesterone (PR) and androgen (AR), detailed immunohistochemical evaluations were performed in the Sprague-Dawley rat oviduct during pre-and neonatal development, estrous cycle and pre-implantation period. In addition, real-time RT-PCR studies were conducted to evaluate changes in ERα, ERβ, total PR (PR-A+B), PR-B and AR mRNA expressions. All receptors except for ERβ were detected in epithelial, and stromal or mesenchymal cells of the fetal and neonatal oviduct, and increased with development. During the estrous cycle and early pregnancy, ERα and PR-A+B were expressed in epithelial, stromal and muscle cells throughout the oviduct region, and showed changes in expression predominantly in the isthmus. Only a few epithelial cells in the infundibulum (INF) and ampulla (AMP) showed ERβ staining. AR was detected in stromal and muscle cells throughout the oviduct region, and in epithelial cells of the INF/AMP. Taken together, ERα, PR-A+B and AR were detected in the epithelium of the INF/AMP region, but all of these receptors were expressed in a distinct subset of epithelial cells which were negative for β-tubulin IV, a ciliated epithelial cell marker. These results contribute to a better understanding of the respective roles of ERs, PRs and AR in the rat oviduct.

Sex Steroid Hormone Receptors in the Developing Female Reproductive Tract of Laboratory Rodents

“…Neonatal PR-A+B ontogeny in oviduct has been reported in mice (Li, 1994) and rats (Okada et al, 2003). Li (1994) demonstrated that in mice, staining of the epithelial PR was weak to positive from ND 1 to 3, Ohta et al (1996) Epi and moderately positive from ND 7, stromal and muscular PR was evident from ND 1.…”

“…In a quantitative real-time RT-PCR study, oviductal ERα mRNA increased until neonatal day (ND) 3, and was maintained at a high constant level through ND 20. However, ERβ mRNA was detected in the oviduct in a low and constant manner, as compared with ERα, throughout pre-and postnatal development (Okada et al, 2003). In the immunohistochemical study of cell-and region-specificity (Table 2), epithelial ERα was weak at birth (ND 0) and exhibited moderate stainings from ND 3 to 20.…”

“…However, some epithelial cells showed a negative or moderate PR signal in the differentiated INF/AMP region from ND 7 to 20. A double immunohistochemical study on PR-A+B with β-tubulin IV revealed that PR-A+B is expressed specifically in ciliated epithelial cells, but not in nonciliated cells, the same as ERα (Okada et al, 2003). In contrast, epithelial PR staining was intense in the differentiated IST/UTJ region, and showed moderate and marked signals on ND 7 to 10, and ND 15 to 20, respectively.…”

“…Although the stimulation of ER signaling accelerates the differentiation process of ciliated epithelial cells, the presence of cilia in the αERKO mouse oviduct suggests that it is not fundamentally required for this event in the ERα-negative ciliated epithelial cells of the adult oviduct (Okada et al, 2004a). Double immunohistochemical staining for ERα with β-tubulin IV was reported in the determination of surface epithelial cell types expressing ERα (Okada et al, 2003). The ciliated cells were positive for β-tubulin IV, while the nonciliated (secretory) cells were negative for it.…”

“…Kurita et al (2001) also reported negative immunostaining for PR-A+B in mesenchymal cells of the uterus, upper vagina, and lower vagina during prenatal development in mice. In order to investigate the differential expression of PR isoform mRNAs in the oviduct, two distinct primer pairs were used; one detected A and B isoforms equally and the other was specific for B isoform (Okada et al, 2003). Oviductal PR-A+B and PR-B were equally expressed at low levels from 15 dpc until birth.…”