Lower susceptibility of low density lipoprotein to in vitro oxidation in diabetic patients

The susceptibility to peroxidative stress of low density lipoprotein (LDL), induced by incubation with CuSO4, has been studied in eleven diabetic patients and eleven control subjects. Our results suggest that oxidized LDL (OX-LDL) of diabetic patients have a significant higher reactivity to 2,4,6-trinitrobenzene sulfonic acid (TNBS) than controls, that indicates a lower susceptibility of LDL to oxidative stress. Furthermore using the fluorescence polarization (Pf) of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its phosphatidylcholine derivative (DPH-PC) we have shown that peroxidation induces a decrease of fluidity in OX-LDL of controls and diabetic patients, both at the lipoprotein surface, where is localized DPH-PC and at the interface between lipoprotein surface and core which is probed by DPH.