Lipoprotein metabolism: exogenous, endogenous and reverse cholesterol transport pathways, the LDL receptor and PCSK9
The three lipoprotein pathways and their apolipoproteins, lipoprotein lipase and its regulators, LDL receptor recycling and PCSK9, how each lipid-lowering drug acts on these steps, Friedewald LDL calculation, and the inherited disorders that map onto each step.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Lipids travel in lipoproteins: a core of triglyceride and cholesteryl ester, a surface of phospholipid, free cholesterol and apolipoproteins that act as ligands and enzyme cofactors.
- Three pathways:
- Exogenous: dietary fat → chylomicrons (apoB-48) → remnants to liver.
- Endogenous: liver → VLDL (apoB-100) → IDL → LDL → LDL receptor.
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Sources
- Braunwald's Heart Disease, 12th editionElsevier (Libby P, Bonow RO, Mann DL et al.), 2022
- Australian guideline for assessing and managing cardiovascular disease riskAU/NZCommonwealth of Australia (Australian Chronic Disease Prevention Alliance), 2023
- Mach F, Koskinas KC, Roeters van Lennep JE et al. 2025 Focused Update of the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J 2025;46(42):4359-4378European Society of Cardiology and European Atherosclerosis Society, 2025
- Inclisiran (Leqvio) PBS medicine statusAU/NZPharmaceutical Benefits Scheme, Australian Government, 2024
- Novartis announces Lp(a)HORIZON Phase III topline results for pelacarsen in patients with elevated Lp(a) and established cardiovascular diseaseNovartis, 2026
- Goldstein JL, Brown MS. The LDL receptor. Arterioscler Thromb Vasc Biol 2009;29:431-8Arteriosclerosis, Thrombosis, and Vascular Biology, 2009
- Barter PJ, Caulfield M, Eriksson M et al. Effects of torcetrapib in patients at high risk for coronary events (ILLUMINATE). N Engl J Med 2007;357:2109-22New England Journal of Medicine, 2007
- Last updated
- 14 November 2026
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