Overview of lipid metabolism. Triglycerides enter the circulation via the exogenous or endogenous pathway. In the exogenous pathway, dietary fats are absorbed in the intestines and packaged into triglyceride-rich particles, the chylomicrons. These large particles lose some of triglyceride and in the process are converted to chylomicron remnant, a step catalyzed by lipoprotein lipase. Chylomicron remnant is removed by specific hepatic receptors. The liver can also synthesize VLDL, a triglyceride-rich lipoprotein that also contains Apo-B₁₀₀. Triglyceride is removed from VLDL via LPL and is converted first to IDL and then LDL. LDL are principally removed from the circulation by specific hepatic receptors.