Figure 7.

LDL modified by the MPO-H₂O₂-NO₂^– system induces lipid loading of macrophages from wild-type mice but not from CD36-null mice. Thioglycollate-elicited MPM from wild-type mice (a and c) and from CD36-null mice (b and d) were grown for 24 hours in RPMI-1640 containing 10% FBS. Cells were then incubated for 72 hours in the same media containing catalase (100 nM), BHT (20 μM), and vitamin E (20 μM) in the presence of the following lipoprotein preparations (75 μg/mL): LDL incubated with isolated human MPO, a H₂O₂-generating system (GGOx), and NO₂^– in sodium phosphate buffer (50 mM, pH 7.0) supplemented with DTPA (100 μM) at 37°C for either 8 hours (a and b) or 24 hours (c and d) as described in Methods. Cells were fixed with 4% formaldehyde and stained with hematoxylin and oil red-O. ×300.