Differential effects of heparin on NO and tumor necrosis factor-alpha production in bovine blood mononuclear cells stimulated with Salmonella typhimurium lipopolisaccharide

We investigated the influence of heparin. one of the extracellular matrix ( ECM) components, on nitric oxide (NO) and tumor necrosis factor-alpha (TNF- alpha) production by bovine peripheral blood mononuclear cells (PBMC) and m onocytes left to adhere for 2 (freshly adherent monocytes) and 48 h (restin g monocytes), activated with Salmonella typhimurium lipopolysaccharide (LPS ). After 24-h stimulation with LPS, heparin (100 mug/ml) increased (by abou t 40%) NO production by peripheral blood mononuclear cells and by freshly a dherent monocytes. However. it did not change NO synthesis by the resting m onocytes. Unlike its influence on NO level, heparin diminished TNF-alpha pr oduction bp PBMC and monocytes stimulated with LPS. Microscopical examinati on of PBMC stained with biotin-labeled heparin, showed that both lymphocyte s and monocytes were able to bind this glycosaminoglycan. We suggest that h eparin, as a component of ECM. modulates the early response of monocytes to exogenous stimuli. (C) 2001 Elsevier Science Ltd. All rights reserved.