Figure 11.

Cholesteryl oleate synthesis (a), cholesteryl ester mass (b), and cholesterol mass (c) of cells exposed to LDL modified by the MPO-H₂O₂-NO₂^– system. [¹²⁵I]LDL (0.2 mg/mL) was incubated with isolated human MPO (30 nM), glucose (100 μM), glucose oxidase (20 ng/mL), and NO₂^– (500 μM) in sodium phosphate buffer (50 mM, pH 7.0) supplemented with DTPA (100 μM) (complete system) or the indicated additions or deletions. Lipoproteins were then incubated with thioglycollate-elicited MPMs, and the extent of cholesteryl [¹⁴C]oleate formation (a), cellular cholesteryl ester mass (b), and free cholesterol mass (c) was determined as described in Methods. Data represent the mean ± SD of triplicate determinations. Similar results were observed in 3 independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001 for comparison vs. LDL modified by MPO and an H₂O₂-generating system only (– NO₂^–). No significant cholesteryl [¹⁴C]oleate formation or increase in cholesteryl ester or free cholesterol mass above basal values was observed in LDL preparations modified by the complete system in the absence of either MPO or GGOx. Hi catalase, heat-inactivated catalase.