Metabolism of radiolabelled chylomicron lipids in intact and hepatectomized rats

1. 1. Intact rats removed more radiolabelled triacylglycerol, cholesterol, and cholesterol ester but not phosphatidylcholine (PC) in the first 6 min than hepatectomized rats. 2. 2. There was no difference between intact and hepatectomized rats in the transfer of radiolabelled chylomicron lipids to other lipoproteins. 3. 3. Specific radioactivity measurements demonstrated a net transfer of PC (intact and hepatectomized rats) and unesterified cholesterol (intact rats only) onto both the low density lipoprotein/high density lipoprotein-I (LDL/HDL₁) and HDL₂ fractions. 4. 4. [³H]Fatty acids were rapidly incorporated into blood cell phospholipids and into HDL and LDL cholesterol esters of both intact and hepatectomized rats. 5. 5. Substantial rearrangements of [³H]palmitate occurred during lipid uptake by liver.