atherosclerosis Flashcards
cholesterol
- essential component of animal cell membranes, allows fluidity
- dietary sources: animal fats; cholesterol biosynthetic p/way (25% total cholesterol production occurs in the liver)
HMG CoA Reductase
converts HMG CoA to Mevalonic Acid, essential for cholesterol synthesis
triglycerides
ester
- glycerol & fatty acids
- one of the main components in animal fat and vegetable oils
- store and circulate fat
lipoproteins
complex of lipids and PRO, hydrophobic core w cholesteryl esters and triglycerides
- unesterified cholesterol, phospholipids, apoproteins at membrane
- enable transport of lipids, TG, cholesterol
- PRO components of lipoproteins are called apolipoproteins
exogenous lipid metabolism
- absorption of dietary cholesterol and FA
- in intestinal cell: FFA combine with glycerol to form TG; cholesterol esterified to form cholesterol esters via ACAT; TG and cholesterol are assembed into chylomicrons
- enter circulation
- lipoprotein lipase removes TG in extrahepatic tissues, remnants taken up by hepatocytes
Apolipoproteins on HDL
A1, AII, C, E, D (more dense)
Apolipoproteins for LDL
b-100
Apolipoproteins for IDL
b100, E, C
VLDL Apolipoproteins
C, B100, E (less dense, increased diameter)
chylomicron Apolipoproteins
B48, C, E, A1, AII
ENDOgenous pway of cholesterol synthesis
Chylomicron remnants taken up by liver, converted to VLDL. VLDL (TG>CE) loses TG via lipoprotein lipase in tissues and becomes IDL (CE>TG). IDL can be converted to LDL by further removal of TG via hepatic lipase. LDL can be internalized in liver and non hepatic tissues. Liver converts to bile acids and secretes, non hepatic used for hormone prod, cell membrane synth, or stored. Enters macrophages and other tissues to form plaques. HDL formed from hepatic and intestinal synthesis of particles containing phospholipids and apolipoproteins, surface components from triglyceride depeleted chylomicron and VLDL remnants, aquisitiion of free chol from tissue sites and other lipoproteins. HDL converts to IDL if too much is produced.
TG can be stored or _____
produce nutrients via liver
Total cholesterol: desirable, borderline, high
240
LDL: desirable, borderline, high
160
HDL: high; desirable
> 60; men: > 40; women: >50
triglycerides: desirable, borderline, high
200
rx of borderline high hypercholesterolemia
dietary and lipoprotein analysis, possible drug therapy if CHD or 2 other risk factors (male, family history of CHD, smoker, HTN, low HDL, diabetes, obesity