Figure 7.

Rates of lipid synthesis and secretion by primary hepatocytes from wild-type (open circles), TgBP-1a (filled circles), LDLR^–/– (open triangles), and TgBP-1a;LDLR^–/– (filled triangles) mice. Primary hepatocytes were prepared from one mouse of each genotype as described in Methods. The hepatocytes were incubated with DMEM containing 5% FCS for 3 h at 37°C, after which the cells were incubated with 0.5 mM sodium [¹⁴C]acetate (18 dpm/pmol) in DMEM supplemented with 5% human lipoprotein–deficient serum. At the indicated time, the medium was removed for centrifugation at d < 1.006 g/ml, the monolayers were washed, and the cells were harvested. The content of ¹⁴C-labeled cholesterol and fatty acids in cells and medium was quantified as described in Methods. Each value is the average of duplicate incubations. Similar results were obtained in three other experiments in which different groups of mice were studied at a single time point.