title: Study of the effect of ulipristal acetate on human sperm ability to interact with tubal tissue and cumulus-oocyte-complexes.
abstract: OBJECTIVE
  Ulispristal acetate (UPA) is a selective progesterone receptor modulator widely used for emergency contraception (EC). The described main mechanism of action is by inhibiting or delaying ovulation; however, the postovulatory effects of the drug are still on debate. Therefore, the aim of this study was to determine whether UPA could interfere with human sperm fertilizing ability.
  
  
  METHODS
  Human motile spermatozoa were incubated under capacitating conditions with or without UPA, and then used to inseminate human tubal explants, mouse cumulus-oocyte complexes and zona-free hamster eggs. The ability of UPA to interact with human sperm progesterone (P)-binding sites was investigated by incubating the cells with fluorescent-labeled P and analyzing them by fluorescence microscopy.
  
  
  RESULTS
  UPA did not affect the ability of human sperm to bind to human tubal tissue explants surface or to penetrate the mouse cumulus mass and the zona-free hamster eggs. In addition, concentrations of UPA much higher than those present in the plasma of EC pill users were required to bind to human sperm P-binding sites.
  
  
  CONCLUSIONS
  Our study supports a lack of an agonist or antagonist action of UPA on different functional parameters associated with the fertilizing ability of human sperm.
  
  
  CONCLUSIONS
  This study provides new functional evidence supporting that the contraceptive action of UPA is not related to effects on human sperm cells, contributing to a better understanding of the mechanism of action of UPA as EC.
authors.affiliation: Laboratory of Reproductive Medicine, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, (2000) Rosario, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Zumoffen
authors.affiliation: Instituto de Biología y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, (1428) Buenos Aires, Argentina.
authors.forename: Matías D
authors.initials: MD
authors.lastname: Gómez-Elías
authors.affiliation: Laboratory of Reproductive Medicine, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, (2000) Rosario, Argentina.
authors.forename: Adriana M
authors.initials: AM
authors.lastname: Caille
authors.affiliation: Family Planning Clinic, Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas (UNICAMP), Caixa Postal 6181, 13084-971 Campinas, SP, Brazil.
authors.forename: Luis
authors.initials: L
authors.lastname: Bahamondes
authors.affiliation: Instituto de Biología y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, (1428) Buenos Aires, Argentina.
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Cuasnicú
authors.affiliation: Instituto de Biología y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, (1428) Buenos Aires, Argentina.
authors.forename: Débora J
authors.initials: DJ
authors.lastname: Cohen
authors.affiliation: Laboratory of Reproductive Medicine, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, (2000) Rosario, Argentina. Electronic address: slorenzo939@hotmail.com.
authors.forename: María José
authors.initials: MJ
authors.lastname: Munuce
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D044363:Contraception, Postcoital; D003271:Contraceptive Agents, Female / Q000494:pharmacology*; D006224:Cricetinae; D054885:Cumulus Cells / Q000502:physiology; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D009649:Norpregnadienes / Q000378:metabolism / Q000494:pharmacology*; D011374:Progesterone / Q000378:metabolism; D011980:Receptors, Progesterone / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology*
chemical_list: D003271:Contraceptive Agents, Female; D009649:Norpregnadienes; D011980:Receptors, Progesterone; D011374:Progesterone; C555622:ulipristal acetate
keywords: Emergency contraception; Fertilization; Human spermatozoa; Progesterone; Ulipristal acetate