Inverse relationship of ethane or n-pentane and malondialdehyde formed during lipid peroxidation in rat liver microsomes with different oxygen concentrations

When we incubated rat liver microsomes with ferrous ions and an NADPH-regenerating system, ethane and n-pentane formation increased correspondingly with decreasing concentrations of oxygen in the atmosphere above the incubation, whereas malondialdehyde increased with increasing oxygen concentrations up to a plateau. At very low oxygen concentrations - 100% helium as atmosphere, but presumably traces of oxygen were present in the microsomes - ethane and n-pentane formation were maximal and dependent on the concentrations of ferrous ions, in the case of ethane, a peak being reached at about 20 microM Fe2+, whereas n-pentane continuously increased with increasing concentrations of Fe2+. It is suggested that the inverse relationship of ethane or n-pentane and malondialdehyde is due to two different reaction sequences of microsomal lipid peroxidation with different oxygen sensitivities.     

A survey of chemicals inducing lipid peroxidation in biological systems

A great number of drugs and chemicals are reviewed which have been shown to stimulate lipid peroxidation in any biological system. The underlying mechanisms, as far as known, are also dealt with. Lipid peroxidation induced by iron ions, organic hydroperoxides, halogenated hydrocarbons, redox cycling drugs, glutathione depleting chemicals, ethanol, heavy metals, ozone, nitrogen dioxide and a number of miscellaneous compounds, e.g. hydrazines, pesticides, antibiotics, are mentioned. It is shown that lipid peroxidation is stimulated by many of these compounds. However, quantitative estimates cannot be given yet and it is still impossible to judge the biological relevance of chemical-induced lipid peroxidation.