title: S-nitroso-N-acetyl penicillamine inhibits spontaneous exit from metaphase-II arrest in rat eggs cultured in vitro.
abstract: BACKGROUND
  Present study was designed to investigate the in vitro effects of nitric oxide (NO) donor such as S-nitroso-N-acetyl penicillamine (SNAP) on spontaneous exit from metaphase-II arrest (SEM-II) in rat eggs cultured in vitro.
  
  
  METHODS
  Ovulated eggs were denuded and then exposed to various concentrations (0.0, 0.01, 0.1 and 1.0mM) of SNAP for 3h under in vitro culture conditions. The percentage of SEM-II, specific and total phosphorylated cyclin-dependent kinase-1 (Cdk1), cyclin B1 and anaphase promoting complex/cyclosome (APC/C) levels as well as Cdk1 activity were analyzed.
  
  
  RESULTS
  The SEM-II was associated with a decrease of Thr-161 phosphorylated Cdk1 as well as cyclin B1 levels and increase of Thr-14/Tyr-15 phosphorylated Cdk1, APC/C levels and Cdk1 activity in aged eggs cultured in vitro. On the other hand, SNAP treatment prevented a decrease of Thr-161 phosphorylated Cdk1 as well as cyclin B1 levels and increase of Thr-14/Tyr-15 phosphorylated Cdk1, Cdk1 activity that finally prevented SEM-II in a concentration-dependent manner. However, APC/C level was not affected by SNAP during the course of treatment in vitro.
  
  
  CONCLUSIONS
  Present data suggest that SNAP prevented SEM-II possibly by increasing high level of NO and thereby maturation promoting factor (MPF) stabilization in rat eggs cultured in vitro. Hence, SNAP could be used to prevent SEM-II that reduces reproductive outcome in several mammalian species.
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, U.P., India.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Prasad
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, U.P., India. Electronic address: shailchaubey@gmail.com.
authors.forename: Shail K
authors.initials: SK
authors.lastname: Chaube
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D006736:Horses; D006801:Humans; D008677:Metaphase / Q000187:drug effects* / Q000502:physiology; D009865:Oocytes / Q000187:drug effects* / Q000502:physiology; D010062:Ovulation Induction / Q000379:methods; D051381:Rats; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology*
chemical_list: D026423:S-Nitroso-N-Acetylpenicillamine
keywords: Cyclin B1; Cyclin-dependent kinase 1; MPF; Reproductive outcome; Spontaneous exit from metaphase-II arrest