title: The involvement of MMP-2 and MMP-9 in heart exercise-related angiogenesis.
abstract: BACKGROUND
  Little is known about the involvement of matrix metalloproteinases (MMPs) in cardiac vascular remodelling induced by exercise. Our aim was to evaluate and localize MMP-2 and MMP-9's activities in relation to capillary proliferation in mouse hearts trained for 15, 30 and 45 days.
  
  
  METHODS
  Sixty-three mice were randomly assigned to 7 groups: four control sedentary groups (C0, C15, C30 and C45) and three groups trained by an endurance protocol (T15, T30 and T45). MMP-2 and MMP-9 were examined with zymography and immunostaining analyses. Capillary proliferation was evaluated counting the number of CD31-positive cells.
  
  
  RESULTS
  Different activity patterns of the latent form of both MMPs were found. Pro-MMP-9 increased after 15 days of training; whereas pro-MMP-2 gradually decreased after 30 and 45 days of training below the control groups. The latter was inversely correlated with capillary growth. MMP-9 was mainly localized in myocardiocytes and less evident in capillaries. Conversely, MMP-2 was more intense in capillary endothelial cells and slightly in myocardiocytes.
  
  
  CONCLUSIONS
  A different spatiotemporal modulation of pro-MMP-2 and pro-MMP-9 activities has been detected in the myocardium during angiogenesis related to the aerobic training. These results can be useful to draw up training protocols for improving the performance of healthy and diseased human hearts.
authors.affiliation: Department of Legal, Society and Sport Sciences, University of Palermo, Via E, Duse 2, 90146 Palermo, Italy. marianna.bellafiore@unipa.it.
authors.forename: Marianna
authors.initials: M
authors.lastname: Bellafiore
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Battaglia
authors.forename: Antonino
authors.initials: A
authors.lastname: Bianco
authors.forename: Felicia
authors.initials: F
authors.lastname: Farina
authors.forename: Antonio
authors.initials: A
authors.lastname: Palma
authors.forename: Antonio
authors.initials: A
authors.lastname: Paoli
mesh_terms: D000818:Animals; D002196:Capillaries / Q000201:enzymology / Q000254:growth & development*; D003331:Coronary Vessels / Q000201:enzymology / Q000254:growth & development*; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051379:Mice; D018919:Neovascularization, Physiologic; D010805:Physical Conditioning, Animal; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9