Figure 3. Chylomicrons from Ces1/Es-x^−/− mice present with abnormal composition.

(A) Immunoblotting showing plasma apolipoprotein B composition from mice injected with P-407. Plasma samples were prepared at the indicated times. Representative data from 3 independent experiments. (B) Immunoblotting showing apolipoprotein composition of chylomicrons isolated from wild-type and Ces1/Es-x^−/− mice. Representative data from 3 independent experiments. (C) Chylomicron lipid composition. Chylomicrons were isolated lipids extracted and levels measured using commercial kits. N = 5 mice/group. PL, glycerophospholipids; C, total cholesterol. (D) Chylomicron size. Chylomicrons were isolated from wild-type and Ces1/Es-x^−/− mice and size was evaluated by dynamic light scattering at 25°C. N = 5 mice/group, 5 measurements per sample. (E) Chylomicron secretion. Overnight fasted mice were injected with P-407, followed by an olive oil bolus containing radiolabeled triolein. Blood was collected at the indicated times and plasma prepared. Lipids were extracted, spotted onto TLC plates and resolved. Lipids were visualized by exposure to iodine, and radioactivity in TG was counted in a scintillation counter. N = 6 mice/group, *<p0.05 vs. wild-type. (F) Chylomicron apolipoprotein B secretion rate. Chylomicrons were collected through lymph duct cannulation. Proteins from 2 µL of lymph were resolved by SDS-5%PAGE and immunoblotted for apoB. Plasma control (1 µL) in the farthest right lane.