Effect of Carrageenan on the Development of Hypersensitivity (Schistosoma mansoni Egg) and Foreign Body (Divinyl-Benzene Copolymer Beads and Bentonite) Granulomas
The effect of carrageenan on the development of hypersensitivity and foreign body granulomas was examined. Repeated intraperitoneal injections of the polysaccharide caused a strong suppression of the primary, hypersensitivity granulomas forming around the eggs of Schistosoma mansoni worms in the lungs of mice, but had no effect on the secondary, enhanced egg granulomas in the previously sensitized animals. Carrageenan treatment virtually abolished the granulomatous reactions forming around plastic beads or bentonite particles. It is concluded that carrageenan exerted its suppressive effect not through macrophage toxicity but rather by affecting plasma factors which regulate vascular permeability and cellular traffic during the process of inflammation.