The Differential Suppression of Antigen, Lymphokine and Mitogen-Induced Delayed Hypersensitivity-Type Skin Reactions by Carrageenan

Intraperitoneal administration of carrageenan to guinea pigs produced differential suppression of delayed hypersensitivity (DH)-type skin reactions. The order of suppression was antigen-induced > skin reactive factor > concanavalin A. The relationship of the known in vitro cytotoxic effect of carrageenan for macrophages to these findings is discussed. It was concluded that carrageenan probably did not suppress DH lesions by exclusive in vivo macrophage cytotoxicity. It appeared that carrageenan affected both the afferent and efferent limbs of the DH response and that the afferent limb was particularly sensitive. The possibility that the suppressive effects of carrageenan may be mediated by plasma factors is discussed.