SOMATOSTATIN-INDUCED MODULATION OF INFLAMMATION IN EXPERIMENTAL ARTHRITIS

Objective. To study the antiinflammatory effect of different doses of intraarticular somatostatin in experimental arthritis in rabbits. Meth ods. Chronic arthritis was induced by a single injection of fibrin int o the knee joint of rabbits previously sensitized to this antigen. The effects of sequential intraarticular injections of somatostatin into the rabbit knee, at doses of 500, 750, and 1,000 mu g, were monitored by measuring knee joint circumferences and hematologic parameters. The measurements were compared with those obtained following use of triam cinolone acetonide and placebo. At the end of the experiments, the kne e joints were examined histologically. Results. Somatostatin treatment induced a statistically significant and dose-related reduction of kne e joint swelling. This effect was shorter than that produced by triamc inolone acetonide; however, the antiinflammatory activity elicited by successive doses of triamcinolone acetonide declined both in extent an d duration, while the effects of somatostatin remained unchanged at ea ch successive treatment. Histopathologic observations showed that both somatostatin and triamcinolone acetonide reduced the inflammatory sig ns in the joint structures, although triamcinolone acetonide appeared to be more effective. Conclusion. These findings suggest that somatost atin exerts an antiinflammatory effect in this model of experimental a rthritis and may represent a valid and safer alternative to corticoste roids for intraarticular therapy of arthritis.