title: Damaging effect of cumulus denudation on rabbit oocytes.
abstract: OBJECTIVE
  To study the effect of cumulus denudation on in vitro maturation of rabbit oocytes.
  
  
  METHODS
  Experimental animal study.
  
  
  METHODS
  Academic institution.
  
  
  METHODS
  Rabbits and mice.
  
  
  METHODS
  Rabbit oocytes were observed compared with mouse oocytes.
  
  
  METHODS
  Developmental competence, membrane integrity, and apoptotic status of oocytes after cumulus denudation.
  
  
  RESULTS
  Although in vitro maturation of mouse cumulus-denuded oocytes was unaffected, rabbit cumulus-denuded oocytes could not mature. However, 50% of rabbit cumulus-intact oocytes matured normally when their gap junctions were sealed with 1-heptanol. Coculture with cumulus cells did not improve maturation of rabbit cumulus-denuded oocytes unless with an intact corona radiata. Staining with Hoechst 33258, Bcl-2 antibodies, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling showed membrane breaches or apoptosis of rabbit cumulus-denuded oocytes, contrary to the mouse cumulus-denuded oocytes. Ultrastructurally, rabbit oocytes showed no perivitelline space but numerous long cell junctions projecting into the egg cortex, contrary to the mouse oocytes. However, the damaging effect of cumulus denudation was much relieved after preincubation of rabbit cumulus-intact oocytes with phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, and some cumulus-denuded oocytes prepared after preincubation matured and developed into blastocysts.
  
  
  CONCLUSIONS
  [1] Cumulus denudation severely damaged rabbit oocytes leading to their apoptosis or degeneration, possibly because of the deep-set junctional complexes anchoring the oocyte and corona cells; and [2] preincubation with phosphodiesterase inhibitor may provide a method to avoid the damaging effect of cumulus denudation on rabbit oocytes.
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, People's Republic of China.
authors: Jin-Hua
authors: JH
authors: Lu
authors: Jun-Zuo
authors: JZ
authors: Wang
authors: Hui-Li
authors: HL
authors: Wang
authors: Hong-Shu
authors: HS
authors: Sui
authors: Yong
authors: Y
authors: Liu
authors: Jing-Jing
authors: JJ
authors: Li
authors: Bo
authors: B
authors: Liang
authors: Jing-He
authors: JH
authors: Tan
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D002470:Cell Survival; D002478:Cells, Cultured; D018920:Coculture Techniques; D054885:Cumulus Cells / Q000473:pathology*; D005260:Female; D017629:Gap Junctions / Q000187:drug effects / Q000473:pathology; D019850:Heptanol / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D051379:Mice; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011817:Rabbits; D013997:Time Factors
chemical_list: D010726:Phosphodiesterase Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D019850:Heptanol; D015056:1-Methyl-3-isobutylxanthine