Studies on lipid peroxidation using isolated rat liver cells: the role of singlet oxygen in the propagation of lipid peroxidation ADP-Fe3+ or CCl4 induced.

The separation of lipid peroxidation reactions in two sequential parts, initiation and propagation, has been proposed. Furthermore, it has been shown that some of the propagation reactions following the peroxidative breakdown of membrane lipids may produce singlet oxygen, a highly excited, energetic species of molecular oxygen. To investigate whether singlet oxygen is involved in the propagation of ADP-Fe3+ or CCl4-induced lipid peroxidation, hepatocytes in single cell suspension were treated with the two mentioned drugs in the presence or in the absence of 1,4-diazabicyclo-[2,2,2]octane (DABCO), a known scavenger of singlet oxygen. Only the stimulation of malonaldehyde production due to ADP-Fe3+ was partially prevented by high concentrations of the scavenger, while the CCl4-induced increase of malonaldehyde was not influenced. The results reported here suggest that ADP-iron complex stimulates lipid peroxidation in a way that is somehow different from that occurring in the case of CCl4 poisoning.