title: Differential localisation of the renin-angiotensin system in de-novo lesions and in-stent restenotic lesions in in-vivo human coronary arteries.
abstract: OBJECTIVE
  Different components of the renin-angiotensin system (RAS) have been demonstrated in atherosclerotic plaques. However, the involvement of the RAS in in-stent restenosis is not clear. We studied the differential immunolocalisation of angiotensin converting enzyme (ACE) and the angiotensin II type 1 (AT1) receptor in de-novo stenotic lesions and in-stent restenotic lesions in human coronary arteries.
  
  
  METHODS
  Using a pullback atherectomy catheter, biopsies from de-novo coronary lesions (n=19) and in-stent restenotic lesions (n=19) were obtained. The biopsies were immunostained for vascular smooth muscle cells (VSMCs), macrophages, ACE and the AT1 receptor.
  
  
  RESULTS
  In biopsies from de-novo stenotic lesions ACE-positive macrophages were more numerous than in in-stent restenotic lesions (P=0.002). Moreover, in the latter lesions, ACE-positive macrophages decreased when the time interval of stent implantation was longer. On the other hand, in-stent restenotic lesions contained predominantly young VSMCs, which abundantly expressed AT1 receptors.
  
  
  CONCLUSIONS
  Lesional ACE expression is not a prominent feature of in-stent restenotic lesions. In contrast, AT1 receptors are abundantly expressed on young VSMCs. In de-novo lesions ACE and AT1 receptors were found on macrophages and VSMCs, which were present in all specimens.
authors.affiliation: Department of Cardiology, Thoraxcenter, University Hospital of Groningen, Groningen, The Netherlands.
authors.forename: Lodewijk J
authors.initials: LJ
authors.lastname: Wagenaar
authors.forename: Ad J
authors.initials: AJ
authors.lastname: van Boven
authors.forename: Allard C
authors.initials: AC
authors.lastname: van der Wal
authors.forename: Giovanni
authors.initials: G
authors.lastname: Amoroso
authors.forename: René A
authors.initials: RA
authors.lastname: Tio
authors.forename: Chris M
authors.initials: CM
authors.lastname: van der Loos
authors.forename: Anton E
authors.initials: AE
authors.lastname: Becker
authors.forename: Wiek H
authors.initials: WH
authors.lastname: van Gilst
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D023903:Coronary Restenosis / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D003331:Coronary Vessels / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000201:enzymology / Q000473:pathology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000473:pathology; D007703:Peptidyl-Dipeptidase A / Q000032:analysis*; D044140:Receptor, Angiotensin, Type 1 / Q000032:analysis*; D012084:Renin-Angiotensin System; D015607:Stents
chemical_list: D044140:Receptor, Angiotensin, Type 1; D007703:Peptidyl-Dipeptidase A