Differential localisation of the renin-angiotensin system in de-novo lesions and in-stent restenotic lesions in in-vivo human coronary arteries.
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.
Wagenaar
Lodewijk J
LJ
Department of Cardiology, Thoraxcenter, University Hospital of Groningen, Groningen, The Netherlands.
van Boven
Ad J
AJ
van der Wal
Allard C
AC
Amoroso
Giovanni
G
Tio
René A
RA
van der Loos
Chris M
CM
Becker
Anton E
AE
van Gilst
Wiek H
WH
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
D044140:Receptor, Angiotensin, Type 1; D007703:Peptidyl-Dipeptidase A