The involvement of polymorphonuclear leukocytes in the pathogenesis of bronchopneumonia in calves. I. Activated granulocyte induced lipid peroxidation in red blood cells.

The influence of free radicals generated by polymorphonuclear leukocytes from bronchopneumonic calves on lipid peroxidation in red blood cells was studied. Incubation of granulocytes with red blood cells causes a rise in malondialdehyde production in these cells in linear dependence on the granulocyte number. Incubation of red blood cells with malondialdehyde causes a generation of adduct moiety of this compound with phosphatidylserine and phosphatidylethanolamine. This adduct is also present in erythrocytes which have been incubated with neutrophils of bronchopneumonic calves. Cytochrome c loaded erythrocyte ghosts showed a high reduction rate of this compound during incubation of ghosts with neutrophils of diseased calves. It is suggested that neutrophils of bronchopneumonic calves are in an activated state in the blood-stream, and free radicals generated by these cells are capable of peroxidizing the red blood cell membrane lipids and causing cross-links between phospholipid moieties in erythrocyte membranes.