The effects of levan on the acute inflammatory response.

The fructose polymer levan has been shown to affect the accumulation of leucocytes in inflammatory lesions. The present study has investigated the effect of levan on experimental pleurisy induced by carrageenan and calcium pyrophosphate dihydrate (CPPD) crystals. Total pleural polymorphonuclear leucocyte counts and exudate volumes were significantly reduced by levan treatment. We were, however, unable to detect any effect on mononuclear cell numbers. Furthermore, levan treatment significantly reduced peripheral leucocyte numbers. The counter-irritant activity of levan was compared with that of a known counter-irritant, dextran. The ability of levan to reduce pleural polymorph numbers and exudate volume could not be accounted for totally by counter-irritation. Studies using an in-vitro leucocyte adhesion assay system indicate that levan affects leucocyte adhesion to vascular endothelium.