Effects of sera and exudate from carrageenan-treated rats on two models of acute inflammation.

The air bleb has been studied as a cavity suitable for the production of a chronic inflammatory response. The ability of carrageenan and CPPD crystals to produce a chronic response in this cavity has been studied and the nature of the reaction described quantitatively and qualitatively. Carrageenan produced a fluid exudation predominated by mononuclear cells and histologically chronic in nature. However, CPPD failed to produce an inflammatory response apart from the formation of a few foreign body giant cells. Using the model described, experiments were undertaken to examine the ability of exudates and sera taken from animals undergoing either an acute or chronic reaction to modify two models of acute inflammation. Firstly the carrageenan complement dependent pleurisy and secondly the CPPD complement independent pleurisy. Volume of chronic and acute total cell numbers were reduced by chronic and acute exudates and sera on the carrageenan pleural model. No significant effect was on the CPPD pleural model.