title: Expression of ER-α and ER-β during peri-implantation period in uterus is essential for implantation and decidualization in golden hamster.
abstract: OBJECTIVE
  The role of estrogen in embryo implantation in golden hamster (Mesocricetus auratus) is still ambiguous. In order to clarify it, we investigated the spatial distribution and expression of estrogen receptors, ER-α and ER-β in the uterus of pregnant hamster during peri-implantation period and identified the effect of estrogen receptor antagonist ICI-182,780 on the embryo implantation.
  
  
  METHODS
  We performed in vivo experiments on early pregnant hamsters involving treatment with ICI-182,780, an estrogen receptor antagonist. Immunohistochemistry, western blot analysis and quantitative PCR were employed to evaluate the spatio-temporal distribution and expression of ER-α and ER-β in the uterus of normal early pregnant and treated hamsters.
  
  
  RESULTS
  Results showed that embryo implantation was completely absent in ICI-182,780 treated uterine horn while, normal implantation occurred in control and vehicle treated horns. Both the receptors were differentially expressed in the uterus of hamster from day 1 (D1) to day7 (D7). In contrast, treated horns without any implantation site showed no trace of any receptors. Protein and mRNA expression of both the receptors were high around the day of implantation while, ER-β expression was up-regulated on D7 of embryo implantation. P value˂0.05 is considered significant.
  
  
  CONCLUSIONS
  Spatio-temporal expression of ERs in the uterus during peri-implantation period have crucial role for endometrium receptivity and implantation in hamster. Recurrent implantation failure is the devastating problem among the desirable couple and is mainly due to defect in endometrium receptivity. This study may provide a new insight to manage the problem of idiopathic infertility.
authors.affiliation: Embryo Physiology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India. Electronic address: randhirkumarbt@gmail.com.
authors.forename: Randhir
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Indian Institute of Vegetable Research (IIVR), Varanasi, India. Electronic address: akhileshgzp@gmail.com.
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Yadav
authors.affiliation: Embryo Physiology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India. Electronic address: pakrasi_bhu@yahoo.co.in.
authors.forename: P L
authors.initials: PL
authors.lastname: Pakrasi
mesh_terms: D000818:Animals; D006224:Cricetinae; D003656:Decidua / Q000378:metabolism*; D010064:Embryo Implantation; D004958:Estradiol / Q000031:analogs & derivatives / Q000737:chemistry; D065171:Estrogen Receptor Antagonists / Q000737:chemistry; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism; D005260:Female; D000077267:Fulvestrant; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008647:Mesocricetus; D011247:Pregnancy; D011270:Pregnancy, Animal; D013997:Time Factors; D014599:Uterus / Q000378:metabolism*
chemical_list: D065171:Estrogen Receptor Antagonists; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D000077267:Fulvestrant; D004958:Estradiol
keywords: ER-α; ER-β; Embryo implantation; Estrogen; ICI-182780; Uterus