Volatile alkanes produced by erythrocytes: an assay for in vitro studies on lipid peroxidation

Lipid peroxidation in erythrocytes is currently studied by measuring the formation of malonyldialdehyde (MDA). A new and simple methodological approach to the measurement of the extend of lipid peroxidation is described here. Erythrocytes from freshly drawn human blood were washed and suspended in isoosmotic phosphate-buffered saline and incubated with sodium azide to inhibit the catalase. Oxidation of red cell lipids was induced by the addition of hydrogen peroxide. MDA formation was measured by the 2-thiobarbituric acid (TBA) reaction. After the same procedure of incubation the production of volatile alkanes (pentane, ethane, ethylene, n-butane, and propane) was estimated by gas chromatography. The total amount of pentane formation from red cells after 120 min of incubation with hydrogen peroxide was much higher than of the other alkanes. This assay provides a useful model to elucidate the role of lipid peroxidation of erythrocytes and is a simple method to study changes in their membrane lipid in diseases and red cell aging.