title: Induction of angiotensin converting enzyme in neointima after intravascular stent placement.
abstract: BACKGROUND
  To investigate the morphological changes of the arterial wall and the expression of angiotensin converting enzyme (ACE) in the arterial wall after stent placement in a canine model.
  
  
  METHODS
  Seventeen mongrel dogs underwent stent placement (Gianturco's Z stent) in the aorta. Six animals were sacrificed at 4 weeks after stent implantation, and the other 5 animals at 12 weeks. The normal aorta was harvested from 6 dogs. The specimens were stained with hematoxylin-eosin (H&E) as well as by immunohistochemistry (smooth muscle specific a-actin, and ACE). Histomorphometric analysis was performed using the sections stained with H&E and smooth muscle specific a-actin.
  
  
  RESULTS
  The total intimal area was significantly increased at all time points as compared with the control aorta. The a-actin positive intimal area was also significantly increased at all time points as compared with the control aorta. In the control aorta, luminal endothelial cells as well as a-actin positive medial cells occasionally exhibited faint cytoplasmic staining for ACE. In the 4- and 12-week stented aorta, a-actin positive cells in the neointima and media as well as macrophages in the adventitia stained strongly positive for ACE.
  
  
  CONCLUSIONS
  ACE was induced in the neointima after stent placement of the canine aorta. Considering its multiple biological actions, ACE may be associated with the pathogenesis of neointimal hyperplasia after stent placement.
authors.affiliation: Department of Cardiovascular Surgery, Hokkaido University School of Medicine, Sapporo, Japan. tnishibe@med.hokudai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Nishibe
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
authors.forename: F
authors.initials: F
authors.lastname: Kudo
authors.forename: J
authors.initials: J
authors.lastname: Flores
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Nagato
authors.forename: T
authors.initials: T
authors.lastname: Kumada
authors.forename: K
authors.initials: K
authors.lastname: Yasuda
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D001011:Aorta / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D004195:Disease Models, Animal; D004285:Dogs; D006083:Graft Occlusion, Vascular / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D006965:Hyperplasia / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D032389:Myocytes, Smooth Muscle / Q000473:pathology / Q000502:physiology; D007703:Peptidyl-Dipeptidase A / Q000032:analysis*; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D017539:Tunica Intima / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D017540:Tunica Media / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
chemical_list: D000199:Actins; D007703:Peptidyl-Dipeptidase A