EPR detection of nitric oxide in liver from iron overloaded rats

MONICA GALLEANO; LUCILA AIMÓ; MARÍA V. BORRONI; SUSANA PUNTARULO

Iguazu, Argentina

Congreso; Oxidant and antioxidant signaling in cell response; 1998

MCBN-UNESCO

EPR detection of nitric oxide in liver from iron overloaded rats Monica Galleano, Lucila Aimó, María V.Borroni and Susana Puntarulo Laboratory of free radical biology- Physical Chemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina The effect of in vivo iron overload on nitric oxide (NO) formation both with and without exposure to bacterial lipopolysacharide, was examined in rat liver. Male adults Wistar were injected with saline solution (control); Escherichia coli lipopolysacharide 4 mg/Kg prepared in saline solution (LPS); iron-dextran 200 mg/Kg (Fe), and iron-dextran 200 mg/Kg plus LPS 4 mg/Kg simultaneously (Fe + LPS). After 5 h of treatment, 2.2 mmol/Kg diethyldithiocarbamate (DETC) was administrated to all the animals, and after 30 min liver samples were obtained. The signal dependent on Bis (dithiocarbamate)-Fe-NO complexes was determined by EPR in liver homogenates at room temperature. The spectra show only the characteristic triplet EPR signal of DETC2-Fe-NO complex. Doubly integrated area of the first-derivative signals were calculated and expressed as arbitrary units (AU). As previously described, LPS administration lead to a significant increase in DETC2