Abstract | OBJECTIVE: METHODS: Sections of synovia from patients with rheumatoid arthritis (n = 7), osteoarthritis (n = 7) or chondromalacia patellae (n = 6) were tested for immunoreactivity for ACE, and for binding of the ACE inhibitor [(125)I]351A. The amount of ACE was measured with computer assisted image analysis as the proportion of synovial section area occupied by ACE-immunoreactive cells, and the density of [(125)I]351A binding. RESULTS: [(125)I]351A binding sites had characteristics of ACE and colocalised with ACE-like immunoreactivity to microvascular endothelium and fibroblast-like stromal cells in inflamed and non-inflamed human synovium. Stromal [(125)I]351A binding densities (B(eq)) and the fraction of synovial section area occupied by ACE-immunoreactivity (fractional area) were higher in synovia from patients with rheumatoid arthritis (B(eq) 28 amol/mm(2), fractional area 0.21) than from those with osteoarthritis (B(eq) 9 amol/mm(2), fractional area 0.10) or chondromalacia patellae (B(eq) 9 amol/mm(2), fractional area 0.09)(p < 0.05). Density of [(125)I]351A binding to stroma was similar to that to blood vessels in rheumatoid arthritis, but less dense than vascular binding in chondromalacia patellae and osteoarthritis. Increases in [(125)I]351A binding densities were attributable to increases in the numbers of binding sites, and were consistent with an increase in the density of ACE bearing stromal cells. CONCLUSION:
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Authors | D A Walsh, J Catravas, J Wharton |
Journal | Annals of the rheumatic diseases
(Ann Rheum Dis)
Vol. 59
Issue 2
Pg. 125-31
(Feb 2000)
ISSN: 0003-4967 [Print] England |
PMID | 10666168
(Publication Type: Journal Article)
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Chemical References |
- Angiotensin-Converting Enzyme Inhibitors
- Dipeptides
- Iodine Radioisotopes
- L-proline, N2-((1S)-1-carboxy-3-phenylpropyl)-N6-((4-hydroxyphenyl)iminomethyl)-L-lysyl-
- Peptidyl-Dipeptidase A
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Topics |
- Adult
- Aged
- Angiotensin-Converting Enzyme Inhibitors
(metabolism)
- Arthritis, Rheumatoid
(enzymology)
- Cartilage Diseases
(enzymology)
- Dipeptides
(metabolism)
- Female
- Humans
- Immunoenzyme Techniques
- Iodine Radioisotopes
- Male
- Middle Aged
- Osteoarthritis
(enzymology)
- Peptidyl-Dipeptidase A
(metabolism)
- Stromal Cells
(enzymology)
- Synovial Membrane
(enzymology)
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