Metabolism of VLDL

METABOLISM OF VLDL (Endogenous pathway)

• VLDL (very low density lipoprotein) is synthesized in liver contains high triglyceride, cholestryl ester, cholesterol, phospholipid and Apo B-100.
• Step I- Formation of Nascent VLDL (TGs, Ch, ChE, PLP, Apo B-100)
• Step II- Formation Mature VLDL(TGs, Ch, ChE, PLP, Apo B-100, C, E)
• Step III– Formation of Remnant VLDL (IDL) (TGs, Ch, ChE, PLP, Apo- B-100, E)
• Apo C- II activates Lipoprotein lipase
• Step IV- Fates of IDL(intermediate density lipoproteins)
• IDL is taken up in the liver by apo E Receptor present in the liver.
• IDL is transformed to LDL called as Lipoprotein Cascade pathway.
• Step V- Uptake of VLDL by tissues
• apo B-100 acts as ligand for LDL receptors.
• LDL elevated serum concentration of LDL causes excessive deposition of cholesterol in peripheral tissues and enhance atherosclerosis therefore it predisposes to MI.
• LDL is metabolized by LDL receptor.
• LDL is a bad cholesterol considered as a marker for cardiovascular disease called as lethally dangerous lipoprotein (LDL).
• LDL receptor present in hepatic and extrahepatic tissues.