T-cell mediated vascular dilatation and hemorrhage induced by antitumour polysaccharides

Antitumour polysaccharide lentinan, capable of potentiating T-cell dependent reactions and some other antitumour polysaccharides such as pachymaran, carboxymethyl-pachymaran and zymosan were found to induce vascular dilatation and hemorrhage(VDH) in CD-1 normal mice starting the following day after a single injection. Polysaccharides which do not have the tumour-regressing activity, several immunopotentiators such as BCG, lipopolysaccharide, dextran sulfate and concanavalin A, and chemical mediators of inflammation such as histamine, serotonin and prostaglandin E1 did not induce VDH in mice. This response seems to be mediated by T-cells and macrophages, because VDH was not observed in CD-1 nu/nu mice treated with lentinan, and carrageenan, an antimacrophage drug, inhibited the appearance of VDH by lentinan. Furthermore, carrageenan inhibited the production of the VDH-inducing serum which was caused by lentinan, capable of passively transferring VDH to another mouse.