Synoviocytes, not chondrocytes, release free radicals after cycles of anoxia/re-oxygenation.
By oxymetry and electron paramagnetic resonance (EPR), we investigated the effects of repeated anoxia/re-oxygenation (A/R) periods on the respiration and production of free radicals by synoviocytes (rabbit HIG-82 cell line and primary equine synoviocytes) and equine articular chondrocytes. Three periods of 20 min anoxia followed by re-oxygenation were applied to 10(7)cells; O(2) consumption was measured before anoxia and after each re-oxygenation. After the last A/R, cellular free radical formation was investigated by EPR spectroscopy with spin trapping technique (n=3 for each cell line). Both types of synoviocytes showed a high O(2) consumption, which was slowered after anoxia. By EPR with the spin trap POBN, we proved a free radical formation. Results were similar for equine and rabbit synoviocytes. For chondrocytes, we observed a low O(2) consumption, unchanged by anoxia, and no free radical production. These observations suggest an oxidant activity of synoviocytes, potentially important for the onset of osteoarthritis.
Schneider
Nicole
N
Department of Clinical Sciences, Large Animal Surgery, Faculty of Veterinary Medicine, University of Liège, B41, Sart Tilman, 4000 Liège, Belgium. n.schneider@gmx.net
Mouithys-Mickalad
Ange L
AL
Lejeune
Jean-Philippe
JP
Deby-Dupont
Ginette P
GP
Hoebeke
Maryse
M
Serteyn
Didier A
DA
D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D015687:Cell Hypoxia / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D005609:Free Radicals / Q000378:metabolism; D006736:Horses; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013583:Synovial Membrane / Q000378:metabolism*
D005609:Free Radicals; D017382:Reactive Oxygen Species; D010100:Oxygen