title: Calcium potentiates the effect of estradiol on PGF2α production in the bovine endometrium.
abstract: BACKGROUND
  Estradiol (E2) is required for luteolysis in cows and its injection stimulates prostaglandin F2α (PGF2α) release. The main goal of our study was to investigate the ability of endometrial explants and cells treated with E2 and the calcium ionophore (CI) A23187 to synthesize PGF2α.
  
  
  RESULTS
  Treatment with E2 in vivo resulted in a 48.4% increase of PGF2α production by endometrial explants treated in vitro with A23187. Production of PGF2α was better stimulated with A23187 at concentrations of 10(-6) and 10(-5) mol/L compared with other concentrations used. The concentration of PGF2α for untreated bovine endometrial cell cultures was 33.1 pg/mL, while for cultures treated with E2, A23187, or a combination of E2 and A23187, the PGF2α concentration was 32.5, 92.4 and 145.6 pg/mL, respectively.
  
  
  CONCLUSIONS
  Treatment with A23187 tended to stimulate PGF2α production. In the presence of E2, A23187 significantly stimulated PGF2α synthesis. It appears that A23187 potentiates the effects of E2 with respect to synthesis of endometrial PGF2α in cattle.
authors.affiliation: São Paulo State University, Rod. Comandante João Ribeiro de Barros (SP 294) Km 651, Dracena, SP 17900-000, Brazil.
authors.forename: Claudia Maria
authors.initials: CM
authors.lastname: Bertan Membrive
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: Pauline Martins
authors.initials: PM
authors.lastname: da Cunha
authors.affiliation: Department of Veterinary Medicine, School of Animal Sciences and Food Engineering, University of São Paulo, Pirassununga, Brazil.
authors.forename: Flávio Vieira
authors.initials: FV
authors.lastname: Meirelles
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: Mario
authors.initials: M
authors.lastname: Binelli
keywords: Animal reproduction; Cattle; Estradiol; Luteolysis; PGF2α synthesis; Reproductive physiology