Endogenous Pathway - Cholesterol Metabolism

Endogenous Pathway -

1. Fat & Cholesterol arriving at the Liver or newly synthesised is repackaged into VLDL’s
2. VLDL’s enter the bloodstream between meals & head out to the peripheral tissues
3. VLDL’s meet tissues expressing LPL (muscle & adipose) & release glycerol & fatty acids
4. After the VLDL has lost most of it’s fats it becomes smaller & is known as an IDL
5. Empty HDL is produced as a bi-product – can collect LDL from periphery
6. IDL’s are absorbed from the blood by the liver
7. They are then broken down by Hepatic Lipase intoLDL’s (triglycerides removed)
8. LDL’s have a relatively high cholesterol content with little fatty acids or glycerol
9. LDL circulates & is absorbed by various tissues via binding to LDL receptors
10. Any excess LDL is taken up by the liver via LDL receptors