title: Vascular endothelial growth factor level changes during human embryo development in culture medium.
abstract: OBJECTIVE
  Implantation is a complex phenomenon consisting of the first strong contact between embryo and endometrium. Recent studies have demonstrated that this process is dependent not only on the 'readiness' of the endometrium, but also on complex interactions between endometrial and embryonic tissues that cross-talk by means of different molecules (growth factors, cytokines, vasoactive factors). Investigations performed on human blastocysts indicate a role for vascular endothelial growth factor (VEGF) in these processes. The aim of the present study was to investigate VEGF levels at different stages in human embryo culture medium.
  
  
  METHODS
  We selected 20 women among patients undergoing assisted reproduction with the in vitro fertilization-blastocyst transfer protocol. The oocytes were inseminated by intracytoplasmic sperm injection. For each patient, approximately two cultures of four microinjected oocytes (and then of four embryos) were performed. Each culture of four oocytes/embryos was placed in one dish to increase the probability to detect small VEGF concentrations.
  
  
  RESULTS
  Results showed significantly higher VEGF levels in the medium at blastocyst stage (12.16 +/- 2.80 pg/ml) compared with embryos at pronuclear stage (13.58 +/- 2.32 pg/ml) and microinjected oocytes (12.80 +/- 3.45 pg/ml).
  
  
  CONCLUSIONS
  An important VEGF synthesis by blastocysts occurs during human embryo development.
authors.affiliation: Department of Reproductive Medicine and Child Development, Division of Obstetrics and Gynecology, University of Pisa, Pisa, Italy. g.artini@obgyn.med.unipi.it
authors.forename: Paolo Giovanni
authors.initials: PG
authors.lastname: Artini
authors.forename: Valeria
authors.initials: V
authors.lastname: Valentino
authors.forename: Patrizia
authors.initials: P
authors.lastname: Monteleone
authors.forename: Giovanna
authors.initials: G
authors.lastname: Simi
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Parisen-Toldin
authors.forename: Francesca
authors.initials: F
authors.lastname: Cristello
authors.forename: Vito
authors.initials: V
authors.lastname: Cela
authors.forename: Andrea Riccardo
authors.initials: AR
authors.lastname: Genazzani
mesh_terms: D002478:Cells, Cultured; D002970:Cleavage Stage, Ovum / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000235:genetics* / Q000502:physiology; D005260:Female; D006801:Humans; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000378:metabolism*
chemical_list: D003470:Culture Media; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A