Activities of plasminogen activator, plasmin and kallikrein in synovial fluid from patients with temporomandibular joint disorders.

To measure the activities of plasminogen activator (PA), plasmin and kallikrein, multiple synovial fluid samples were taken from 32 patients with internal derangement (ID) and osteoarthrosis (OA), and nine asymptomatic volunteers. The enzyme activity in synovial fluid from the temporomandibular joint (TMJ) was quantitated by a fluorogenic substrate assay using an enzyme substrate. In fluid samples from the patient group, PA was detected in 24 (31.5%), plasmin in 20 (26.3%) and kallikrein in 53 (96.4%), while none of these enzymes were found in the synovial fluid samples from the control group. There were positive correlations found among PA, plasmin and kallikrein. These results clearly demonstrated increased levels of PA, plasmin and kallikrein activities in the synovial fluid of patients with ID and OA, and suggest that these enzymes may be involved in the pathogenesis of synovitis, as well as the resorption of cartilage and bone in TMJ.