Effect of synovial membrane infection in vitro on equine synoviocytes and chondrocytes
Hardy, J.; Bertone, A.L.; Malemud, C.J.
American Journal of Veterinary Research 59(3): 293-299
1998
ISSN/ISBN: 0002-9645 PMID: 9522948 Document Number: 494337
Synovium and articular cartilage explants were obtained from the midcarpal and tarsocrural joints of adult horses. For experiment 1, synovium explants were incubated as follows: control - incubation in standard medium, infected (I) - incubation with Staphylococcus aureus, and infected-filtered (IF) - incubation with medium collected from the infected group and filtered (0.22- micro m filter). Daily collected medium was assayed for interleukin 1 beta (IL-1 beta ), IL-6, tumour necrosis factor, and hyaluronan (HA) concentrations. For experiment 2, cartilage explants were incubated as follows: control - incubation in standard medium, and IF - incubation in medium collected from infected synovium cultures and filtered. After 48 hours, explant proteoglycan synthesis and endogenous proteoglycan and glycosaminoglycan contents were determined. IL-1 beta and IL-6 values were significantly increased in synovium explants from the I and IF groups. Hyaluronan concentration was lower in I and IF groups. Proteoglycan synthesis and content, and total glycosaminoglycan and chondroitin sulfate concentrations, were significantly decreased in cartilage from the IF group. It is suggested that resident synovial cells may contribute appreciably to articular damage during bacterial infection in the absence of migrant inflammatory cells. This response is prolonged despite elimination of the bacteria.