title: Platelet concentrates: effects of calcium and thrombin on endothelial cell proliferation and growth factor release.
abstract: BACKGROUND
  Clinical evidence suggests that platelet concentrate (PC) could have beneficial therapeutic effects on hard and soft tissue healing, due to the contents of growth factors (GFs) stored in the platelets. The objectives of this study were: 1) to determine the concentrations of platelet-derived growth factor-BB (PDGF-BB), transforming growth factor-beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) released from PCs and whole blood (WB), before and after the addition of various concentrations of calcium and thrombin, and 2) to assess the physiological importance of the released GFs on angiogenesis.
  
  
  METHODS
  WB and PCs were harvested and prepared from three healthy volunteers. Enzyme-linked immunosorbent assay tests, specific for PDGF-BB, TGF-beta1, VEGF, and bFGF, were performed on WB and PC supernatants, collected before and 30 minutes after the addition of various concentrations of calcium and thrombin. The supernatants were also added to human umbilical vein endothelial cell (HUVEC) cultures in order to measure their effects on endothelial cell proliferation.
  
  
  RESULTS
  Growth factor concentrations detected in PC supernatants were significantly greater (280% to 800% increase) than concentrations present in WB supernatants. Calcium and thrombin induced immediate GF release from PCs in a dose-dependent fashion. Furthermore, PC supernatants led to greater HUVEC proliferation rates than WB supernatants. However, there was no correlation between the concentrations of specific GFs and HUVEC proliferation rates.
  
  
  CONCLUSIONS
  These results suggest that PCs could stimulate blood vessel formation. They also reinforce the relevance for using PCs in regenerative therapies.
authors.affiliation: Faculté de Médecine Dentaire and Groupe de Recherche en Ecologie Buccale, Université Laval, Quebec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Lacoste
authors.forename: Isabelle
authors.initials: I
authors.lastname: Martineau
authors.forename: Guy
authors.initials: G
authors.lastname: Gagnon
mesh_terms: D000077214:Becaplermin; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000097:blood; D006133:Growth Substances / Q000096:biosynthesis* / Q000097:blood; D006801:Humans; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010982:Platelet-Derived Growth Factor / Q000032:analysis / Q000096:biosynthesis; D020574:Proto-Oncogene Proteins c-sis; D013917:Thrombin / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000097:blood
chemical_list: D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D000077214:Becaplermin; D005346:Fibroblast Growth Factors; D013917:Thrombin; D002118:Calcium