title: Cryopreservation of canine ovarian cortex using DMSO or 1,3-propanediol.
abstract: Cryopreservation of ovarian cortex is potentially an important tool for the conservation of endangered species. It will allow preserving the large pool of primordial and primary follicles to retrieve fertilizable oocytes in the future. The aim of this study was to evaluate the effects of slow freezing on the morphology and viability of canine follicles after thawing using DMSO or 1,3-propanediol (PROH) as cryoprotectants. Slices of canine ovarian tissue were equilibrated for 20 minutes at 20 °C in minimum essential medium containing either cryoprotectants at 1.5 M, and then frozen by a standardized protocol. Morphology of follicles after thawing was analyzed by means of histology and transmission electron microscopy, and viability was assessed using Trypan blue and fluorescent probes. The exposure of dog ovarian tissue to both cryoprotectants before freezing had no effect on follicular morphology and viability. Also after freezing, follicles remained histologically normal, but transmission electron microscopy revealed damage of ultrastructure in follicles, which were exposed to PROH. Postthaw viability was significantly reduced with 65.7% of the follicles remaining alive in DMSO and 48.7% in PROH. In conclusion, this study demonstrated the survival of canine oocytes within ovarian cortex cryopreserved by slow freezing using 1.5-M DMSO.
authors.affiliation: Laboratory of Manipulation of Oocytes and Preantral Follicles, Faculty of Veterinary, State University of Ceará, Fortaleza, Ceará, Brazil; Laboratory of Electron Microscopy, Institute of Biology, University of Brasília, Brasília, Federal District, Brazil. Electronic address: claudio@pixplus.com.br.
authors.forename: Cláudio Afonso Pinho
authors.initials: CA
authors.lastname: Lopes
authors.affiliation: Laboratory of Manipulation of Oocytes and Preantral Follicles, Faculty of Veterinary, State University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Anelise Maria Costa Vasconcelos
authors.initials: AM
authors.lastname: Alves
authors.affiliation: Department of Reproduction Biology, Leibniz-Institute for Zoo and Wildlife Research, Berlin, Germany.
authors.forename: Katarina
authors.initials: K
authors.lastname: Jewgenow
authors.affiliation: Laboratory of Electron Microscopy, Institute of Biology, University of Brasília, Brasília, Federal District, Brazil.
authors.forename: Sônia Nair
authors.initials: SN
authors.lastname: Báo
authors.affiliation: Laboratory of Manipulation of Oocytes and Preantral Follicles, Faculty of Veterinary, State University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: de Figueiredo
mesh_terms: D000818:Animals; D002470:Cell Survival; D015925:Cryopreservation / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004285:Dogs / Q000502:physiology*; D005260:Female; D010053:Ovary / Q000502:physiology*; D011409:Propylene Glycols / Q000494:pharmacology*; D013194:Staining and Labeling
chemical_list: D003451:Cryoprotective Agents; D011409:Propylene Glycols; C041787:1,3-propanediol; D004121:Dimethyl Sulfoxide
keywords: Dog; Electron microscopy; Histology; Oocyte; Slow freezing; Viability