Figure 4.

Cholesterol accumulation of differentiated macrophages. Human monocytes were differentiated for 7 days in the presence of M-CSF or GM-CSF. Macrophage cultures were subsequently incubated in triplicate with 0 or 2 mg/ml LDL for 24 hours and their cholesterol and protein contents were determined. Shown is the net cholesterol accumulation of macrophages incubated with LDL compared with macrophages incubated without LDL for the indicated conditions. M-Mac spontaneously accumulated significant quantities of LDL-derived cholesterol relative to GM-Mac (P < 0.05). Activation of the subpopulations with PMA (1 μg/ml) increased cholesterol accumulation in GM-Mac without a change in M-Mac. Data are presented as the mean ± SD for three monocyte donors.