Nitric oxide effects on human erythrocytes structural and functional properties--an in vitro study.

NO is present in the blood at 10(-7) M under physiological conditions, but at concentrations higher than 10(-6) M during inflammatory disease states. The aim of this study was to characterize what are the effects of these different NO concentrations on erythrocyte structural and functional properties. Blood was collected from eleven healthy men and incubated with SpermineNONOate in order to expose it during incubation time to NO concentrations between 10(-7) M and 10(-3) M. We measured erythrocyte aggregation and deformability, membrane lipid peroxidation and fluidity, p50, hemoglobin, oxyhemoglobin, methemoglobin concentrations and plasma pH, pO(2), pCO(2), Na(+), K(+) and Ca(2+). When blood was exposed to NO 10(-7) M erythrocyte deformability increase and p50 decrease. In presence of NO 10(-5) M lipid fluidity and p50 decrease. When blood was exposed to NO 10(-3) M methemoglobin concentration increase and erythrocyte deformability and p50 decrease but membrane fluidity and lipid peroxidation were similar to control. In conclusion, dependent of NO concentrations there is different effects on erythrocytes structural and functional properties.