<p>J774 macrophages enriched with <sup>3</sup>H-cholesterol were incubated with apoA-I WT or A164S and cholesterol efflux quantified as a function of protein concentration (A) or time (B) by scintillation counting of the resulting treatment media. An ACAT inhibitor and CPT-cAMP were used to prevent formation of cholesteryl esters of the <sup>3</sup>H-cholesterol and to induce expression of ABCA1, respectively. Data from concentration gradient experiments were fitted using the Michaelis-Menten equation. Time dependent efflux treatments were performed with 50 μg/ml apoA-I WT or A164S. Each figure represents 3 independent experiments and displays mean±SD. (C) ApoA-I WT or A164S were incubated with rat serum for 2 h followed by incubation with J774 macrophages enriched with <sup>3</sup>H-cholesterol for 2 h (10 μg/ml apoA-I). Rat serum was used as control for background efflux. Data is mean ±SEM (**** = p<0.0001, n = 3).</p
