Cyclooxygenase activity in chondrocytes from osteoarthritic and healthy cartilage.

OBJECTIVES: To compare prostaglandin production and cyclooxygenase activity in high-density primary cultures of chondrocytes from patients with osteoarthritis and from healthy controls. METHODS: Chondrocytes harvested from operative specimens obtained during hip or knee arthroplasty were cultured at a very high density for 48 h. Cyclooxygenase activity was evaluated based on prostaglandin E2 levels (radioimmunological assay) after addition of arachidonic acid. The chondrocytes were cultured with and without IL-1 beta and TNF alpha. RESULTS: Prostaglandin E2 production and cyclooxygenase activity were significantly higher in cultures of chondrocytes from osteoarthritic than from healthy joints. Adding IL-1 beta to the osteoarthritic chondrocyte cultures further increased the high cyclooxygenase activity, whereas adding TNF alpha alone had no effect. CONCLUSION: Cultured chondrocytes from osteoarthritic joints showed increased prostaglandin E2 production and cyclooxygenase activity.