Fig. 4.

Apolipoprotein E overexpression increases cholesterol efflux from macrophage foam cells toward plasma. Thioglycollate-elicited peritoneal mouse macrophages were loaded with 50 μg/ml acetylated LDL and 1 μCi/ml [³H]cholesterol as described in Materials and Methods. Subsequently, 2% plasma was added to the cells. After 4 h and 8 h, radioactivity within the medium and radioactivity remaining within the cells was determined by liquid scintillation counting. Efflux is given as the percentage of counts recovered from the medium in relation to the total counts present on the plate (sum of medium and cells). Data are presented as means ± SEM. n = 8 mice for each condition. White bars, AdNull-injected mice; black bars, AdhApoE3-injected mice. * Significantly different from the respective AdNull-injected controls as assessed by Mann-Whitney U-test (at least P < 0.05).