Dyslipidemia Flashcards
what is the composition of lipoproteins?
- lipid core - TAGs, cholesterol, cholesterol esters
- phospholipid monolayer
- structural apolipoproteins
what is the function of apo B100?
binds LDL receptor
what is the function of apo B48?
structural role only
what is the function of apoE?
binds LDL receptor
what is the function of apo CII?
activates LPL
what is the function of apo AI?
activates LCAT
where are chylomicrons made?
enterocyte
where are VLDLs made?
liver
where are IDLs made?
circulation from VLDL
where are LDLs made?
in circulation from IDL
where are HDLs made?
liver 80% intestine 20%
what is the major cartage role of chylomicrons?
dietary TAGs
what is the major cartage role of VLDL?
TAGs from LIVER
what is the major cartage role of IDL?
C,CE back to liver, also becomes LDLs
what is the major cartage role of LDL?
C,CE back to liver AND extrahepatic tissue
what is the major cartage role of HDL?
C,CE from extrahepatic tissue back to liver
what is the role of HMG CoA reductase?
reduces HMD-CoA conversion to mevalonic acid in cholesterol biosynthesis (liver, intestine)
what is the rate limiting step in cholesterol biosynthesis?
HMG CoA reductase
what is the role of lipoprotein lipase?
hydrolyzes TG core of chylomicrons, VLDL, and IDL
LPL is induced by what molecule?
insulin
where is LPL located in the body?
capillary walls
what is the role of hepatic lipase?
hydrolyzes TAG in IDL to facilitate conversion to LDL
what is the role of cholesterol ester transfer protein (CETP)?
transfers cholesterol esters from HDL to other lipoproteins in exchange for TG, phospholipids, and cholesterol
where is CETP located?
HDL
what is the role of lecithin cholesterol transferase (LCAT)?
transfers fatty acids from lecithin to C to form CE in HDL - keeps concentration low in the phospholipid monolayer
where is LCAT located?
HDL
which lipoprotein family is atherogenic?
apoB (non HDL)
which has a longer residence time in the plasma - small dense LDL or hepatic LDL?
small dense LDL
what is the morphology of LP(a)?
LDL with an additional apolipoprotein tail attached to apoB
what is the significance of LP(a) with respect to coagulation?
apo(a) has structural similarity to plasminogen and competitively inhibits conversion to plasmin
what is the fate of cholesterol once it is returned to the liver?
conversion to bile acids
chylomicrons are associated with what apoB protein?
apoB 48
VLDL / IDL / LDL are associated with what apoB protein?
apoB 100
which apolipoprotein is present in HDL?
apoA-1
apoA-1 is present in which lipoprotein family?
HDLs
what is the screening regimen for dyslipidemia?
lipid profile every well adult over 20 every 5 years
small dense LDL development is promoted by what conditions?
- insulin resistance
- high TG
- low HDL