Abstract

Although the expressions of the estrogen receptor (ER) subtypes have been demonstrated in a large number of estrogen target tissues, to date no evidence has been reported as to how the expressions of the alpha (alpha) and beta (beta) ER subtype mRNA alter in the rat uterus during pregnancy. The aims of the present study were to obtain information concerning the changes in the ER and the progesterone receptor (PR) in early pregnancy and to determine the alterations in the ER subtype mRNA in the pregnant rat uterus. To demonstrate the ER and PR densities, radioligand saturation assay was used. The reverse-transcription-polymerase chain reaction (RT-PCR) was applied to characterize the alterations in the ER subtype mRNA. ER expression was highest on day 5 of pregnancy (Bmax = 637.40 +/- 76.10 fmol/mg). The PR expression did not change significantly until day 8, but the protein density was increased on day 8 of pregnancy. The ERalpha mRNA expression was active during pregnancy, maximum expression was attained on day 5; a gradual decrease was then observed until the second half of pregnancy when its expression continuously increased up to the day of labor (day 22). Since the attachment of the blastocyst, an event that is dependent on estradiol in the progesterone-primed uterus of the rat, occurs on day 5 of pregnancy and the levels of the ER protein and the ERalpha mRNA on day 5 of pregnancy was the highest, it could be supposed that this subtype of ER might regulate implantation. The ERbeta mRNA was detected only from day 7 to day 15, with a maximum level on day 8. The expression of this ER subtype might be related to the development of decidual tissue.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.