[Effect of piroxicam on the structure and function of joint cartilage]

Experimental studies on the dog were performed to investigate possible deleterious effects of non steroidal anti-inflammatory agents, in particular piroxicam, on healthy articular cartilage. Piroxicam, diclofenac, and indomethacin were administered orally to beagles over an 8-week period. Control animals received empty capsules during the same period. A variety of morphological investigations were carried out on the tissues of the knee joint following treatment. Macroscopically and at light microscopical level no differences in the structure of cartilage or synovial membrane were detected between control and test animals. Similarly, with the transmission electron microscope, no structural changes were observed between control and test groups (piroxicam-treated). The incorporation of radioactively labeled sulfur into cartilage proteoglycans was similar in piroxicam-treated and control dogs. Related studies involving the addition of piroxicam to isolated chondrocytes in vitro showed that the proliferative capacity and proteoglycan synthesis of chondrocytes were unaffected by this antirheumatic agent. It is concluded that piroxicam exerts no damaging effect on normal cartilage in the knee joint of the dog.