The effect of primary products of lipid peroxidation on the transmembrane transport of calcium ions

Abstract Permeability of lipid bilayer membranes to Ca 2− was increased when the membranes were formed from oxidized lipids or when initiators of lipid peroxidation, ascorbate and iron ions, were added to both sides of the membrane. Permeabilities for other divalent and monovalent cations also were increased, but there was a substantially higher selectivity for the divalent cations. Similarly, the Ca 2+ permeability of vesicles of sarcoplasmic reticulum increased when exposed to iron:ascorbate. However, the increase in Ca 2+ permeability was not as great as with addition of the ionophore A23187. Thus, it appears that the primary products of lipid peroxidation are the simplest inductors of transmembrane cation transport.