Evidence in vitro that hepatic lipase reduces the concentration of apolipoprotein A-I in rabbit high-density lipoproteins.
Incubation of rabbit plasma in vitro with hepatic lipase resulted in the hydrolysis of triacylglycerol in high-density lipoproteins (HDL) and a reduction in HDL particle size. These changes were accompanied by a decrease in the concentration of apolipoprotein A-I (apo A-I) in the HDL. The loss of apo A-I was demonstrated independently by ultracentrifugation, size exclusion chromatography and gradient gel-immunoblot analysis. It was unrelated to hydrolysis of HDL phospholipids but did correlate with the reduction in HDL particle size. These studies suggest that the concentration of apo A-I in HDL may be influenced by factors which regulate the metabolism of HDL core lipid constituents.
Clay
M A
MA
Baker Medical Research Institute, Melbourne, Australia.
Rye
K A
KA
Barter
P J
PJ
D000818:Animals; D016632:Apolipoprotein A-I; D001054:Apolipoproteins A / Q000097:blood / Q000378:metabolism*; D002845:Chromatography; D004285:Dogs; D006868:Hydrolysis; D066298:In Vitro Techniques; D008049:Lipase / Q000494:pharmacology*; D008075:Lipoproteins, HDL / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D010316:Particle Size; D010741:Phospholipases A / Q000494:pharmacology; D010743:Phospholipids / Q000097:blood; D011817:Rabbits; D014280:Triglycerides / Q000097:blood; D014461:Ultracentrifugation
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D008075:Lipoproteins, HDL; D010743:Phospholipids; D014280:Triglycerides; D008049:Lipase; D010741:Phospholipases A