FIG. 5.
Hepatic lipid analysis and lipid metabolism. (A) Thin-layer chromatography analysis of lipids isolated from Adfp+/+ (+/+) and Adfp−/− (−/−) mouse livers. Lipids were extracted using 0.2 g of liver from an individual mouse, dried under nitrogen, reconstituted in chloroform, and loaded on to a TLC plate. Lipid standards were used to identify each lipid band. Lipid fractions were visualized using iodine vapor. (B) VLDL secretion after inhibition of lipoprotein lipase by Triton WR1339 treatment. Eight-week-old mice (male; n = 5) were fasted for 4 h, and plasma samples were taken as baseline (time zero). Plasma TG was measured at time zero and every hour for 4 h after Triton WR1339 treatment. (D) Intralipid clearance. Eight-week-old mice (n = 6) were infused with intralipid through the tail vein. Plasma TG levels are expressed as a percentage of the peak value measured 5 min after intralipid injection. (D) Oleic acid uptake in primary hepatocytes. Hepatocytes were isolated from male mice (n = 4). Individually isolated cells were separated into tubes for fatty acid uptake assay (Materials and Methods) in the presence of [3H]oleic acid; the reaction was stopped by the addition of phloretin solution at different time points. Cells were washed and pelleted by centrifugation, and radioactivity was determined by scintillation counting.