Open AccessClearance of calcium pyrophosphate dihydrate crystals in VIVO
Author(s) -
Mccarty Daniel J.,
Palmer David W.,
Garancis John C.
Publication year - 1981
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780240513
Subject(s) - calcium , in vivo , pyrophosphate , chemistry , materials science , medicine , biochemistry , biology , enzyme , microbiology and biotechnology
Synthetic triclinic calcium pyrophosphate dihydrate crystals, uniformly labeled with 85 Sr and 45 Ca, were injected into the knee joints of 2 normal adult rabbits and 2 rabbits previously injected repeatedly with autologous blood. The “half clearance time” of the injected crystal mass was 20.4 and 19 days from control joints, nearly identical to previously reported values in 6 rabbits (19.1 ± 1.4), and 28.8 and 34 days from the joints injected with blood, a significant difference ( P < 0.05). Iron stains showed hemosiderin granules in the superficial synovium in these joints. Electron microscopy showed crystals with a molar calcium/phosphorus ratio of 1.0 and particles containing iron within synovial cells. We hypothesize that the decreased clearance rate from hemosiderotic synovium is due to inhibition of one or more intracellular pyrophosphatases by iron.