Figure 5.

Uptake of cell-derived ³H-labeled cholesterol by apoE-containing lipoproteins in plasma from wild-type E^+/+, E^−/−, and E^−/−hTgE^+/0 mice. Mouse plasma was incubated for 1 min with ³H-cholesterol-labeled normal human fibroblasts. Lipoproteins from aliquots of plasma (40 μl) were then separated by 2D-PAGGE in parallel with a nonradiolabeled sample. Anti-apoE-immunoblots of 2D-electropherograms of E^+/+ plasma were used to localize lipoproteins (see Fig. 3). The area containing the liporoteins were removed from the native gels, their lipids were extracted, and the radioactivity was counted. For further details, see Materials and Methods. The bars represent the percentage of radioactivity in 40 μl of medium released into the various lipoproteins and reflect mean data of two independent experiments. The percentages do not add to 100% because some lipoproteins were not removed from the gel or did not migrate into the gel (e.g., remnants) and because of incomplete recovery.