title: Effects of beta-mercaptoethanol and cycloheximide on survival and DNA damage of bovine embryos stored at 4 degrees C for 72 h.
abstract: The objectives of this study were to determine the effects of cycloheximide (CHX) and beta-mercaptoethanol (beta-ME) during storage of in vitro-produced (IVP) bovine blastocysts for 72 h at 4 degrees C on their survival, hatching capacity and DNA damage. In Experiment 1, when blastocysts were stored in a medium supplemented with 25, 50 or 100 microg/mL of CHX, or 25, 50 or 100 microM of beta-ME, the blastocysts stored with 25 microg/mL of CHX had a significantly higher survival rate than that of the blastocysts stored without CHX (79.5% versus 54.2%). In contrast, beta-ME had no apparent effects on the survival and hatching capacity of stored embryos. In Experiment 2, to investigate synergistic effects of CHX and beta-ME during storage of blastocysts on their developmental parameters and DNA damage, they were stored in the medium with CHX (25 microg/mL) and beta-ME (50 microM). The combination of CHX and beta-ME had no significant effects on the survival of blastocysts. The proportion (6.8%) of DNA-fragmented cells in the blastocysts stored with CHX was similar to that (5.4%) in the non-stored blastocysts (positive control) and significantly lower than that (9.7%) in the blastocysts stored without CHX and beta-ME (negative control). However, there were no significant differences among the proportions of dead cells of blastocysts in the storage groups. Therefore, the supplementation of CHX in the storage medium had a beneficial effect on the proportions of survival and DNA-fragmented cells in the stored embryos, whereas the beta-ME alone or in combination with CHX had no positive effects on either of these proportions.
authors.affiliation: Laboratory of Animal Reproduction, Department of Veterinary Sciences, Yamaguchi University, Yoshida 1677-1, Yamaguchi 753-8515, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Mori
authors.forename: Takeshige
authors.initials: T
authors.lastname: Otoi
authors.forename: Pimprapar
authors.initials: P
authors.lastname: Wongsrikeao
authors.forename: Budiyanto
authors.initials: B
authors.lastname: Agung
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002417:Cattle / Q000196:embryology*; D003513:Cycloheximide / Q000008:administration & dosage*; D004249:DNA Damage / Q000187:drug effects*; D053938:DNA Fragmentation; D004357:Drug Synergism; D004622:Embryo, Mammalian / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D005260:Female; D020287:In Situ Nick-End Labeling; D008623:Mercaptoethanol / Q000008:administration & dosage*; D013696:Temperature; D014021:Tissue Preservation / Q000379:methods / Q000662:veterinary
chemical_list: D008623:Mercaptoethanol; D003513:Cycloheximide