Collagenase production in the exudate of a novel adjuvant-induced air pouch inflammation model in rats.

To elucidate the role of collagenase in tissue destruction in chronic inflammation (e.g., in rheumatoid arthritis), we established a novel air pouch model in rats. Ten ml of air was injected subcutaneously on the dorsa of F344 rats, and 24 hours thereafter, Freund's complete adjuvant was injected into the air pouch. A remarkably high activity of trypsin-activated collagenase was detected dose-dependently in the pouch fluid at 8 days after the challenge injection. Concomitantly with the increase of collagenase activity, the weight of granuloma formed in the pouch decreased, suggesting that collagenase participates in the resorption of granuloma tissues.