Calcium potentiates the effect of estradiol on PGF2a production in the bovine endometrium

Background: Estradiol (E2) is required for luteolysis in cows and its injection stimulates prostaglandin F2a (PGF2a) 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 PGF2a.Results: Treatment with E2 in vivo resulted in a 48.4% increase of PGF2a production by endometrial explants treated in vitro with A23187. Production of PGF2a was better stimulated with A23187 at concentrations of 10(-6) and 10(-5) mol/L compared with other concentrations used. The concentration of PGF2a 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 PGF2a concentration was 32.5, 92.4 and 145.6 pg/mL, respectively.Conclusions: Treatment with A23187 tended to stimulate PGF2a production. In the presence of E2, A23187 significantly stimulated PGF2a synthesis. It appears that A23187 potentiates the effects of E2 with respect to synthesis of endometrial PGF2a in cattle.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP