The interaction between ruptured erythrocytes and low-density lipoproteins.

Low-density lipoproteins (LDL) are oxidatively modified on interaction with haem proteins. The interaction of ruptured erythrocytes with LDL induces oxidative damage as detected by alterations in electrophoretic mobility and the peroxidation of the polyunsaturated fatty acyl chains. Difference spectroscopy reveals that the amplification of the oxidative process by the haem protein is related to the transition of the oxidation state of the haemoglobin in the erythrocyte lysate from the oxy [X-FeII-O2] to the ferryl [X-FeIV = O] form. The incorporation of the lipid-soluble antioxidant, butylated hydroxy toluene, at specific time points during the LDL-erythrocyte interaction prolongs the lag phase to oxidation and eliminates the oxy-to-ferryl conversion of the haemoglobin. The timescale of this haem conversion is related to the antioxidant status of the LDL.