title: Vitrification of equine oocytes with a polyvinyl alcohol after in vitro maturation with equine growth hormone and insulin-like growth factor-I.
abstract: BACKGROUND
  In vitro fertilization (IVF) procedures are limited by the inability to mature equine oocytes on in vitro methods.
  
  
  OBJECTIVE
  The aim of this study was to evaluate structural integrity of equine oocytes subjected to vitrification with a synthetic polymer (PVA).
  
  
  METHODS
  The effect of eGH and its relationship with IGF-I on in vitro maturation (IVM) were evaluated. Compact cumulus oocytes complexes (n=122) were cultured in TCM-199 with eGH, IGF-I or eGH+IGF-I for 30h at 38.5C in air with 5 % CO2. Oocytes were fixed after IVM or subjected to the vitrification protocol. Cryopreserved oocytes were exposed to 1.4M DMSO+1.8M EG+1 percent PVA for 3min, and then transfer to 2.8M DMSO+3.6M EG+0.6M sucrose+1 % PVA for 1min. After rewarming, oocytes were evaluated by confocal microscopy.
  
  
  RESULTS
  Maturation rates of oocytes were not significant different among groups (P > 0.05), however eGH+IGF-I group can develop the assessment of resumption of meiosis (MI+MII = 86.7 %).
  
  
  CONCLUSIONS
  The oocyte did not show morphological alterations. The use of PVA-copolymer may represent a potential alternative for vitrification of equine oocytes after IVM.
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil. curciobruna@hotmail.com.
authors.forename: Bruna da Rosa
authors.initials: Bda R
authors.lastname: Curcio
authors.affiliation: Department of Population Health and Reproduction, University of California, Davis, CA, USA.
authors.forename: Gabriel Ribas
authors.initials: GR
authors.lastname: Pereira
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil.
authors.forename: Lucas Insaurriaga
authors.initials: LI
authors.lastname: Antunes
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil.
authors.forename: André Nunes
authors.initials: AN
authors.lastname: Boff
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil.
authors.forename: Fernanda Carlini Cunha
authors.initials: FC
authors.lastname: dos Santos
authors.affiliation: Animal Reproduction Laboratory, Veterinary School, Federal University of Pelotas, Brazil.
authors.forename: Thomaz
authors.initials: T
authors.lastname: Lucas
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil.
authors.forename: Carlos Eduardo Wayne
authors.initials: CE
authors.lastname: Nogueira
authors.affiliation: Animal Reproduction Laboratory, Veterinary School, Federal University of Pelotas, Brazil.
authors.forename: Carine Dahl
authors.initials: CD
authors.lastname: Corcini
authors.affiliation: Veterinary Clinics Departament, Veterinary School, Federal University of Pelotas , Pelotas, Brazil.
authors.forename: Irwin
authors.initials: I
authors.lastname: Liu
authors.affiliation: Animal Pathology Department, Veterinary School, Federal University of Pelotas, Brazil.
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Deschamps
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003470:Culture Media; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D019855:Ethylene Glycol / Q000494:pharmacology; D005260:Female; D005307:Fertilization in Vitro; D013006:Growth Hormone / Q000494:pharmacology*; D006736:Horses / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects; D018613:Microscopy, Confocal; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D011142:Polyvinyl Alcohol / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology; D058989:Vitrification
chemical_list: D003451:Cryoprotective Agents; D003470:Culture Media; D013395:Sucrose; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D011142:Polyvinyl Alcohol; D019855:Ethylene Glycol; D004121:Dimethyl Sulfoxide