title: Endometrial and conceptus response to exogenous progesterone treatment in early pregnant gilts following hormonally-induced estrus.
abstract: The aim of the study was to determine how supplementation with exogenous progesterone (P4) affects the expression of genes important for endometrial receptivity and conceptus development during the peri-implantation period in pigs. Gilts with PMSG/hCG-induced first estrus received daily injections of corn oil (CO; n=7) or P4(n=7) on days 3 to 10 after insemination. The dose of P4was 25mg/100kg BW on days 3 and 4 of gestation, then increased to 50mg/100kg BW on days 5 to 10. Blood samples were collected each day to monitor concentrations of circulating P4. Animals were slaughtered on day 12 of pregnancy to obtain endometrial tissue, conceptuses, and uterine luminal flushing (ULF). Gilts in the P4group had consistently greater P4concentrations in the blood compared with controls. Treatment of gilts with P4increased uterine weight and enhanced total protein content and 6-keto PGF1α(a PGI2metabolite) content in the uterine lumen. Moreover, injections of gilts with P4increased the expression of prostaglandin endoperoxide synthase 2, microsomal PGE2synthase and vascular endothelial growth factor A mRNA in the endometrium, but had no effect on gene expression in conceptuses. These results indicate that P4supplementation stimulated the secretory activity of the endometrium and increased the expression of genes responsible for vascular function and luteotropic PGE2synthesis, which are important components of successful pregnancy establishment in pigs. However, no effect of P4treatment was detected in conceptuses.
authors.affiliation: Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Szymanska
authors.affiliation: Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland. Electronic address: a.blitek@pan.olsztyn.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Blitek
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian / Q000187:drug effects*; D004717:Endometrium / Q000187:drug effects* / Q000502:physiology; D004971:Estrus / Q000187:drug effects*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006728:Hormones / Q000378:metabolism / Q000494:pharmacology; D011247:Pregnancy; D011374:Progesterone / Q000008:administration & dosage / Q000494:pharmacology*; D013552:Swine / Q000502:physiology*
chemical_list: D006728:Hormones; D011374:Progesterone
keywords: Conceptus; Endometrial receptivity; Estrus induction; Pig; Pregnancy; Progesterone injections