Alterations in iron and nitric oxide plasmatic content in endotoxemia seems as independent events

GALLEANO M; ROBELLO E; ROUSSEAU I; PUNTARULO S

Carlos Paz, Córdoba, Argentina

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

The aim of this work was to identify the possible link between the increase in nitric oxide (NO) and the plasma Fe content in endotoxemia. Female Sprague-Dawley rats were injected ip with saline solution (C) or LPS (4 mg/kg) and measurements were done 6 h after injections. Blood NO level, detected by EPR as the complex NO-Hb, was significantly higher in LPS as compared to C animals (22±2 and 0.8±0.5 AU respectively, p<0.05). Plasma Fe content (Fer-Color, Wiener lab) was 42% lower in LPS than in C, while labile iron pool (LIP), measured by the fluorescent probe calcein, was not significalty different between C and LPS (0.9± 0.1 and 1.2± 0.4 uM respectively). Protein carbonyl content and the ratio ascorbyl radical content/ascorbate content were increased by 28% and 73% in LPS treated animals as compared to C. No changes were observed in the level of thiols in plasma. Aminoguanidine (AG, a NO synthase inhibitor, 100 mg/kg, ip) inhibited by 68%  the NO increase observed after LPS, but did not affect the decrease in plasma Fe. LIP was 1.4±0.2 and 1.5±0.3 uM after AG and AG+LPS treatments, respectively. These results suggest that Fe decrease would be independent of NO increase in circulation during endotoxemia and the increases observed in the oxidative stress markers in plasma after LPS administration seems not be associated to LIP content. Supported by UBACyT, ANPCyT and CONICET