CHARACTERIZATION OF ZYMOSAN-INDUCED ARTHRITIS IN THE RAT - EFFECTS ONJOINT INFLAMMATION AND CARTILAGE METABOLISM

A single intra-articular (ia) injection of 2 mg zymosan on DO led to t he production of acute periarticular edema followed by subacute erosiv e synovitis. The development of the zymosan-induced arthritis was asso ciated with an initial loss of running activity and with an initial de crease of proteoglycan synthesis. Febrile response was present only on D1. In addition, on D20 synovial pannus led to a marked depletion of the proteoglycan content in the articular cartilage. When injected ia, IL1 beta (1 mu g) provoked similar fever and similar changes in carti lage anabolism, but did not affect cartilage proteoglycan content (D20 ). These results suggest that zymosan-induced synovitis in the rat com bines early prostaglandin-dependent processes (edema, pain, fever) wit h IL1-related effects on cartilage metabolism, thus allowing evaluatio n of chondroprotective drugs.