In:
American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 284, No. 1 ( 2003-01-01), p. H17-H22
Abstract:
Angiotensin-converting enzyme (ACE) is present on the luminal surface of the coronary vessels, mostly on capillary endothelium. ACE is also expressed on coronary smooth muscle cells and on plaque lipid-laden macrophages. Excessive coronary circulation (CC)-ACE activity might be linked to plaque progression. Here we used the biologically inactive ACE substrate 3 H-labeled benzoyl-Phe-Ala-Pro ([ 3 H]BPAP) to quantify CC-ACE activity in 10 patients by means of the indicato r-dilution technique. The results were compared with atherosclerotic burden determined by coronary angiography. There was a wide range of CC-ACE activity as revealed by percent [ 3 H]BPAP hydrolysis (30–74%). The atherosclerotic extent scores ranged from 0.0 to 66.97, and the plaque area scores ranged from 0 to 80 mm 2 . CC-ACE activity per unit extracellular space ( V max / K m V i ), an index of metabolically active vascular surface area, was correlated with myocardial blood flow ( r = 0.738; P = 0.03) but not with measures of the atherosclerotic burden. These results show that CC-ACE activity can be safely measured in humans and that it is a good marker of the vascular area of the perfused myocardium. It does not, however, reflect epicardial atherosclerotic burden, suggesting that local tissue ACE may be more important in plaque development.
Type of Medium:
Online Resource
ISSN:
0363-6135
,
1522-1539
DOI:
10.1152/ajpheart.00452.2002
Language:
English
Publisher:
American Physiological Society
Publication Date:
2003
detail.hit.zdb_id:
1477308-9
SSG:
12
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