title: Effect of oxidized LDL on erythrocyte nitric oxide metabolism.
abstract: OBJECTIVE
  Oxidized low density lipoprotein (ox-LDL) has been reported as an inhibitor of nitric oxide (NO)-mediated dilatation in microcirculation. Oxidized LDL effect on NO metabolism of erythrocytes is not known. Therefore, this study aims to evaluate the effect of ox-LDL on erythrocytes NO metabolism.
  
  
  METHODS
  The effect of different concentrations of human purified ox-LDL (25, 50 and 100 μg/mL) on NO metabolism was evaluated on blood of healthy subjects.
  
  
  RESULTS
  An inhibitory effect of higher concentrations of ox-LDL on erythrocyte NO efflux levels was verified. Concentrations of NO efflux from erythrocytes were lower as consequence of treatments with 50 μg/mL ox-LDL treatment (1.6±0.27 nM) and 100 μg/mL ox-LDL treatment (1.3±0.22 nM) than control (1.9±0.28 nM). Opposite, ox-LDL incubation has a positive effect on GSNO content of erythrocytes. That effect is proportional to concentrations of ox-LDL treatments (10.8±1.4 nM for 25 μg/mL, 12.9±1.5 nM for 50 μg/mL and 12.1±1.9 nM for 100 μg/mL) and is significant relative to control (8.56±0.76 μM) and ACh (8.9±0.52 μM) aliquots.
  
  
  CONCLUSIONS
  Presence of oxidized LDL in erythrocyte NO metabolism induces a decrease of NO efflux amount and an increase on intra-erythrocyte GSNO concentrations. These results suggest a role of ox-LDL in mobilization of NO between NO derivatives molecules in dependence of oxidized LDL concentration. An anti - reactive nitrogene role can be attributed to ox-LDL for its contribution in the erythrocyte scavenged ability for nitric oxide.
authors: Carlota Saldanha Lab, Instituto de Medicina Molecular, Universidade de Lisboa, Lisboa, Portugal.
authors: Patrícia
authors: P
authors: Napoleão
authors: Instituto de Bioquímica Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors: Teresa
authors: T
authors: Freitas
authors: Carlota Saldanha Lab, Instituto de Medicina Molecular, Universidade de Lisboa, Lisboa, Portugal.|Instituto de Bioquímica Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors: Carlota
authors: C
authors: Saldanha
mesh_terms: D004912:Erythrocytes / Q000187:drug effects*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism*
chemical_list: D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D009569:Nitric Oxide
keywords: Oxidized LDL; S-nitrosoglutathione; erythrocyte; nitric oxide