title: Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits.
abstract: OBJECTIVE
  To investigate the VEGF expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits.
  
  
  METHODS
  After partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm) was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. Groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. Sections of 5µm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. To confirm the presence of VEGF in tissues, protein expression was determined by immunohistochemistry.
  
  
  RESULTS
  No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. A progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001). VEGF expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001).
  
  
  CONCLUSIONS
  The latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.
authors.affiliation: Department of Surgery, Division of Urology, Ribeirão Preto Medical School - University of Sao Paulo Ribeirão Preto, SP and Department of Experimental Surgery, Anhanguera-Uniderp University, Campo Grande, MS, Brazil.
authors.forename: André Luís Alonso
authors.initials: AL
authors.lastname: Domingos
authors.forename: Sérgio Britto
authors.initials: SB
authors.lastname: Garcia
authors.forename: José de
authors.initials: Jd
authors.lastname: Bessa Junior
authors.forename: Marcelo Ferreira
authors.initials: MF
authors.lastname: Cassini
authors.forename: Carlos Augusto Fernandes
authors.initials: CA
authors.lastname: Molina
authors.forename: Silvio
authors.initials: S
authors.lastname: Tucci Junior
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D003094:Collagen / Q000032:analysis* / Q000378:metabolism; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D007840:Latex / Q000627:therapeutic use*; D008297:Male; D008567:Membranes, Artificial; D011817:Rabbits; D012038:Regeneration; D013997:Time Factors; D001743:Urinary Bladder / Q000601:surgery*; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis* / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D007840:Latex; D008567:Membranes, Artificial; D042461:Vascular Endothelial Growth Factor A; D003094:Collagen