RESUMEN
Background. Heparin and heparin derivatives with low anticoagulant activity exhibit a wide spectrum of biological functions affecting adhesion, activation and trafficking of luekocytes. Methods. We investigated the in vitro effect of heparin and low molecular weight heparin derivative (LMWH) on nitric oxide (NO) production by human polymorphonuclear leukocytes (PMN). Results. N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated NO production was significantly decreased by heparin at doses of 0.5 and 5 µg/mL, while LMWH was only effective at doses of 50 and 200 µg/mL by means of a mechanism not related to No synthase (NOS) activity. Conclusions. These results support the hypothesis that heparin and LMWH derivatives may offet therapeutic benefit for inflammatory diseases where No plays a protagonic role