title: Cryotolerance of in vitro-produced porcine blastocysts is improved when using glucose instead of pyruvate and lactate during the first 2 days of embryo culture.
abstract: The objective of the present study was to determine the effects of replacing glucose with pyruvate and lactate during the first 48 h of in vitro culture (IVC) in NCSU-23 medium on embryo development, embryo quality and survival of porcine blastocysts after vitrification. To this end, in vitro-produced (IVP) porcine oocytes were cultured with either glucose for 6 days (IVC-Glu) or pyruvate-lactate from Day 0 to Day 2 and then with glucose until Day 6 (IVC-PyrLac). Blastocysts were vitrified on Day 6 using the Cryotop device and, after warming, survival rate and the apoptosis index were evaluated after 24 h incubation in NCSU-23 medium. No significant differences were observed between IVC-Glu and IVC-PyrLac in terms of cleavage rate, blastocyst yield, total number of cells per blastocyst or the apoptosis index (1.82±0.75% vs 3.18±0.88%, respectively) of non-vitrified embryos. However, a significant increase was seen in hatching/hatched blastocysts in the IVC-PyrLac compared with IVC-Glu treatment group (12.71±1.20% vs 3.54±0.47%, respectively). Regardless of treatment, vitrification impaired the survival rate and the apoptosis index. When comparing both treatments after warming, the percentage of apoptotic cells was significantly higher for blastocysts in the IVC-PyrLac compared with IVC-Glu group (18.55±3.49% vs 9.12±2.17%, respectively). In conclusion, under the conditions of the present study, replacement of glucose with pyruvate-lactate during the first 48 h of culture resulted in a lower cryotolerance of IVP porcine embryos.
authors.affiliation: Biotechnology of Animal and Human Reproduction (TechnoSperm), Department of Biology, Institute of Food and Agricultural Technology, University of Girona, Campus Montilivi, E-17071 Girona, Spain. miriam.castillo@udg.edu
authors.forename: M
authors.initials: M
authors.lastname: Castillo-Martín
authors.forename: M
authors.initials: M
authors.lastname: Yeste
authors.forename: R
authors.initials: R
authors.lastname: Morató
authors.forename: T
authors.initials: T
authors.lastname: Mogas
authors.forename: S
authors.initials: S
authors.lastname: Bonet
mesh_terms: D000367:Age Factors; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001755:Blastocyst / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D047108:Embryonic Development / Q000187:drug effects*; D005307:Fertilization in Vitro / Q000662:veterinary; D005947:Glucose / Q000494:pharmacology; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D019344:Lactic Acid / Q000494:pharmacology; D019289:Pyruvic Acid / Q000494:pharmacology; D016019:Survival Analysis; D013552:Swine / Q000196:embryology*; D058989:Vitrification
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose