[Prostaglandin and leukotriene release of synovial tissue in various joint diseases]

Synovial tissue from 37 patients suffering from osteoarthritis, chondrocalcinosis, active and inactive rheumatoid arthritis was investigated. The tissue was obtained during knee surgery and immediately incubated in tyrode solution. PGE2, 6-keto-PGF1 alpha, LTB4 and LTC4 were measured by radioimmunoassay. Calcium ionophore A 23187 stimulated the eicosanoid release significantly. This effect was more pronounced with LT than with PG. In the four different joint diseases there was no significant difference in the PG release. The LTC4 release was significantly lower in inactive rheumatoid arthritis as compared to the other joint diseases. For LTB4 this effect was significant only when compared to osteoarthritis. Indomethacin 10(-5) and 10(-7)mol/l inhibited the PG release from synovial tissue in all joint diseases significantly (p less than 0.05), there was no significant effect on the LT release. LT as well as PG are pro-inflammatory mediators. Non-steroidal anti-inflammatory drugs inhibit only the PG release. The remaining LT synthesis might thus be partially responsible for the lack of efficacy of these drugs in some patients.