title: Vitrification of Rattus norvegicus immature cumulus-oocyte complexes using hyaluronic acid.
abstract: The aim of this study was to assess in vitro meiosis resumption and nuclear maturation of Rattus norvegicus oocytes after vitrification with different cryoprotective solutions. Cumulus-oocyte complexes (COCs) were exposed to an equilibration solution for 4 min placed in cryoprotective solutions for 1 min and vitrified in open pulled straws. Cryoprotective solutions were prepared with 15% ethylene glycol + 15% dimethyl sulfoxide + 0.5 M sucrose and different supplements, to form the following groups: G1, 20% fetal bovine serum in modified phosphate-buffered saline (mPBS); G2, 0.4% bovine serum albumine in mPBS; G3, 1% hyaluronic acid in mPBS; and G4, 0.4% polyvinyl alcohol in mPBS. Seven days after vitrification, the COCs from G1 to G4 were warmed and in vitro matured for 30 h along with the control group. Hoechst staining was performed to assess meiosis resumption and nuclear maturation rates. Control group showed higher meiosis resumption (77.88%) and nuclear maturation rates (55.75%) compared to all vitrified groups. Among the vitrified COCs, G3 showed the highest meiosis resumption and nuclear maturation rates (G1, 26.5 and 15.38%; G2, 22.12 and 11.54%; G3, 34.55 and 20%; G4, 20.17 and 9.24%). Supplementation of the vitrification solution with 1% hyaluronic acid provided better results, compared to the other supplements. Hyaluronic acid can be useful to vitrify rat COCs associated with other cryoprotectant agents.
authors.affiliation: Laboratório de Biologia Celular, Universidade Federal de Ciências da Saúde de Porto Alegre - UFCSPA, Rua Sarmento Leite, 245, Rio Grande do Sul, 90050-170, Brazil. liag.paim@gmail.com.
authors.forename: L M G
authors.initials: LM
authors.lastname: Paim
authors.affiliation: Laboratório de Biologia Celular, Universidade Federal de Ciências da Saúde de Porto Alegre - UFCSPA, Rua Sarmento Leite, 245, Rio Grande do Sul, 90050-170, Brazil. leticialgal@gmail.com.
authors.forename: L L
authors.initials: LL
authors.lastname: Gal
authors.affiliation: Laboratório de Biotecnologia Animal Aplicada, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500 - sala 001 D, Porto Alegre, Rio Grande do Sul, 90050-170, Brazil. rui.lopes@ufrgs.br.
authors.forename: R F F
authors.initials: RF
authors.lastname: Lopes
authors.affiliation: Laboratório de Biologia Celular, Universidade Federal de Ciências da Saúde de Porto Alegre - UFCSPA, Rua Sarmento Leite, 245, Rio Grande do Sul, 90050-170, Brazil. atdo@ufrgs.br.|Laboratório de Biotecnologia Animal Aplicada, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500 - sala 001 D, Porto Alegre, Rio Grande do Sul, 90050-170, Brazil. atdo@ufrgs.br.
authors.forename: A T D
authors.initials: AT
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects* / Q000502:physiology; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology*; D054885:Cumulus Cells / Q000166:cytology*; D005260:Female; D006820:Hyaluronic Acid / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects* / Q000502:physiology; D009865:Oocytes / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D058989:Vitrification / Q000187:drug effects*
chemical_list: D003451:Cryoprotective Agents; D006820:Hyaluronic Acid
keywords: Hyaluronic acid; Maturation; Oocyte; Rat; Vitrification