title: [Metalloproteinase in carotid endarterectomy plaques: increased activity in critical stenosis zones].
abstract: BACKGROUND
  The presence of metalloproteinases in atherosclerotic plaques has been described but their role is not well understood. An increased secretion of these proteolytic enzymes could explain plaque instability and distal embolization.
  
  
  OBJECTIVE
  To measure metalloproteinase activity in atherosclerotic plaques obtained after carotid endarterectomy.
  
  
  METHODS
  Plaques were divided in one segment with and one segment without stenosis, the latter being used as control. Both segments were incubated in culture media for 48 h or were fixed for histology. The conditioned medium was studied using gelatin zimography and digital densitometry. Metalloproteinases were identified by their molecular weight, inhibition with EDTA or Western Blot. Standard histologic study and immunohistochemistry were done.
  
  
  RESULTS
  In stenotic areas, metalloproteinase 9 (92kD) secretion was 260% higher than in regular plaques (191 and 73 Kilopixels/microgram protein respectively p < 0.02). The histological study of stenotic areas showed macrophage infiltration and neoformation of blood vessels.
  
  
  CONCLUSIONS
  The increased secretion of cellular matrix degrading enzyme metalloproteinase 9 in stenotic areas of atherosclerotic plaques, could explain plaque instability and subsequent embolization.
authors.affiliation: Departamento de Enfermedades Cardiovasculares, Facultad de Medicina, P Universidad Católica de Chile, Santiago de Chile.
authors.forename: R
authors.initials: R
authors.lastname: Mertens
authors.forename: F
authors.initials: F
authors.lastname: Valdés
authors.forename: A
authors.initials: A
authors.lastname: Krämer
authors.forename: E
authors.initials: E
authors.lastname: Guarda
authors.forename: C
authors.initials: C
authors.lastname: Acevedo
authors.forename: T
authors.initials: T
authors.lastname: Vergara
mesh_terms: D001161:Arteriosclerosis / Q000201:enzymology*; D002343:Carotid Artery, Internal / Q000201:enzymology; D016893:Carotid Stenosis / Q000201:enzymology*; D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007150:Immunohistochemistry; D008666:Metalloendopeptidases / Q000378:metabolism*
chemical_list: D008666:Metalloendopeptidases
vernacular_title: Metaloproteinasas en placas de endarterectomía carotídea: actividad aumentada en áreas de estenosis crítica.