Heparin and low molecular weight heparin decrease nitric oxide production by human polymorphonuclear cells

Background Heparin and heparin derivatives with low anticoagulant activity exhibit a wide spectrum of biological functions affecting adhesion, activation and trafficking of leukocytes. Methods. We investigated the in vitro effect of heparin and a 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 mu g/mL, while LMWH was only effective at doses of 50 and 200 mu g/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 offer therapeutic benefit for inflammatory diseases where NO plays a protagonic role. (C) 1999 IMSS. Published by Elsevier Science Inc.