title: Reduced levels of intracellular reactive oxygen species and apoptotic status are not correlated with increases in cryotolerance of bovine embryos produced in vitro in the presence of antioxidants.
abstract: The effects of intracellular (cysteine and β-mercaptoethanol) and extracellular (catalase) antioxidant supplementation at different times during in vitro production (IVM and/or in vitro culture (IVC)) on bovine embryo development, intracellular reactive oxygen species (ROS) levels, apoptosis and re-expansion rates after a vitrification-thawing process were examined. Blastocyst frequencies were not affected by either antioxidant supplementation (40.5%-56.4%) or the timing of supplementation (41.7%-55.4%) compared with control (48.7%; P>0.05). Similarly, antioxidants and the moment of supplementation did not affect (P>0.05) the total number of blastomeres (86.2-90.5 and 84.4-90.5, respectively) compared with control (85.7). However, the percentage of apoptotic cells was reduced (P<0.05) in groups supplemented during IVM (1.7%), IVC (2.0%) or both (1.8%) compared with control (4.3%). Intracellular ROS levels measured in Day 7 blastocysts were reduced (P<0.05) in all groups (0.60-0.78), with the exception of the group supplemented with β-mercaptoethanol during IVC (0.88), which did not differ (P>0.05) from that in the control group (1.00). Re-expansion rates were not affected (P>0.05) by the treatments (50.0%-93.0%). In conclusion, antioxidant supplementation during IVM and/or IVC reduces intracellular ROS and the rate of apoptosis; however, supplementation does not increase embryonic development and survival after vitrification.
authors.affiliation: Department of Animal Health School of Veterinary Medicine, UNESP-Universidade Estadual Paulista, Araçatuba, SP 16050-680, Brazil.
authors.forename: Nathália A S
authors.initials: NA
authors.lastname: Rocha-Frigoni
authors.affiliation: Department of Animal Health School of Veterinary Medicine, UNESP-Universidade Estadual Paulista, Araçatuba, SP 16050-680, Brazil.
authors.forename: Beatriz C S
authors.initials: BC
authors.lastname: Leão
authors.affiliation: Brazilian Agricultural Research Corporation, EMBRAPA Pantanal, Corumbá, MS 79320-900, Brazil.
authors.forename: Ériklis
authors.initials: É
authors.lastname: Nogueira
authors.affiliation: Department of Animal Health School of Veterinary Medicine, UNESP-Universidade Estadual Paulista, Araçatuba, SP 16050-680, Brazil.
authors.forename: Mônica F
authors.initials: MF
authors.lastname: Accorsi
authors.affiliation: Department of Animal Health School of Veterinary Medicine, UNESP-Universidade Estadual Paulista, Araçatuba, SP 16050-680, Brazil.
authors.forename: Gisele Z
authors.initials: GZ
authors.lastname: Mingoti
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002417:Cattle / Q000196:embryology / Q000378:metabolism; D002478:Cells, Cultured; D015925:Cryopreservation; D046149:Embryo Culture Techniques / Q000379:methods; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods; D042541:Intracellular Space / Q000378:metabolism; D008297:Male; D017382:Reactive Oxygen Species / Q000378:metabolism*; D058989:Vitrification / Q000187:drug effects
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species