title: Effect of two assisted oocyte activation protocols used to overcome fertilization failure on the activation potential and calcium releasing pattern.
abstract: OBJECTIVE
  To assess the effect of two assisted oocyte activation (AOA) protocols with the use of two calcium (Ca(2+)) ionophores, ionomycin and A23187 (calcimycin), on the intracellular Ca(2+) level in mouse and human oocytes and the fertilization rates.
  
  
  METHODS
  Comparison of two Ca(2+) ionophores, ionomycin and A23187, regarding their capacity to increase the intracellular Ca(2+) level and to support subsequent oocyte activation and development.
  
  
  METHODS
  University hospital research laboratory.
  
  
  METHODS
  Patients undergoing intracytoplasmic sperm injection (ICSI) treatment and B6D2F1 mice.
  
  
  METHODS
  Assisted oocyte activation and microinjection of mouse and human oocytes with sperm.
  
  
  METHODS
  Measurement of the fertilizing and Ca(2+)-releasing ability of human sperm.
  
  
  RESULTS
  Ionomycin was more potent than A23187 in provoking Ca(2+) increases in both mouse and human oocytes with significantly higher amplitude and area under the receiver operating characteristic curve. The oocyte activation rate was significantly higher when mouse oocytes were activated with the use of the ionomycin- rather than the A23187-based AOA protocol. Furthermore, oocyte activation rate was higher when human in vitro matured oocytes were activated with the ionomycin-based AOA protocol, but the difference did not reach statistical significance.
  
  
  CONCLUSIONS
  In both mouse and human oocytes, the AOA protocol that used ionomycin was more efficient than the one that used A23187. Bearing in mind that mammalian fertilization is successful when the total dose of Ca(2+) released reaches a minimal threshold, the use of ionomycin for human AOA might be justified instead of the use of A23187.
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Nikiforaki
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Frauke
authors.initials: F
authors.lastname: Vanden Meerschaut
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Chloë
authors.initials: C
authors.lastname: de Roo
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Yuechao
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Minerva
authors.initials: M
authors.lastname: Ferrer-Buitrago
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
authors.forename: Petra
authors.initials: P
authors.lastname: de Sutter
authors.affiliation: Ghent Fertility and Stem Cell Team, Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium. Electronic address: bjorn.heindryckx@ugent.be.
authors.forename: Björn
authors.initials: B
authors.lastname: Heindryckx
mesh_terms: D000328:Adult; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D061207:Calcium Ionophores / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D046149:Embryo Culture Techniques; D005260:Female; D005298:Fertility / Q000187:drug effects; D005300:Fertility Agents, Female / Q000494:pharmacology*; D005306:Fertilization / Q000187:drug effects*; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D015759:Ionomycin / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D061207:Calcium Ionophores; D005300:Fertility Agents, Female; D000001:Calcimycin; D015759:Ionomycin
keywords: A23187; Assisted oocyte activation; calcium ionophore; fertilization failure; ionomycin