Antihyperlipidemics Flashcards
What are the lowest density lipoproteins?
Chylomicrons
What are the apolipoproteins on chylomicrons?
B48
C
E
A
What are the apolipoproteins on VLDL?
C
B-100 E
What are the apolipoproteins on LDL?
B100
What are the apolipoproteins on HDL?
AI AII C E D
What type of lipoprotein has the highest ratio of TG;cholesterol?
Chylomicrons
Where are chylomicrons synthesized?
Intestines
Where aer VLDLs synthesized?
liver
Where are HDL particles synthesized?
intestines, liver
Cholesterol enters enterocytes through what protein?
Niemann-Pick C1-like protein (NPC1L1)
Once inside the enterocytes cholesterol is reesterified by what enzyme?
acetyl-CoA: cholesterol acyltransferase (ACAT)
What are the apolipoproteins that chylomicrons receive from HDL?
E
C-II
What is the MOA of ezetimibe?
Inhibits NPC1L1
What percent of bile is lost through the feces normally?
5%
What is the function of apolipoprotein CII?
Binds to lipoprotein lipase, causing breakdown of the chylomicron
Where does HDL get its apolipoprotein CII from?
From the reminants of LDL
What is the function of apolipoprotein E on HDL?
Binds to receptor on liver for breakdown
What is lipoprotein lipase, and where is it found?
Enzyme that breaks down chylomicron TGs,
found on cell surface of tissues
What is the consequence of a decrease in apo CII expression?
Hypertriglyceridemia
What are the receptors on the liver that apo E binds to?
remnant receptors
What are the two fates of IDL?
Conversion to LDL
Broken down by liver
What is the apolipoprotein that forms the structural component and is the messenger tag for LDL degradtion by the live ?
B100
What happens to the apolipoproteins on IDLs as they are converted to LDL?
apo E and CII are transferred to HDL
What is the receptor on LDL that serves as the receptor for degradation in the liver?
B100
What is the function of apolipoprotein AI on HDLs?
Facilitates the exchange of cholesterol from macrophages/other cells
What are the tissues in the body that can synthesize cholesterol de novo?
Liver
Gonads
Adrenal cortex
What are the substrates for cholesterol synthesis de novo?
Acetyl-coa and acetoacetyl coa
What is the enzyme that converted HMG CoA to mevalonate, a precursor to cholesterol?
HMG CoA reductase
What is the enzyamtic target of statins?
HMG CoA reducatase
What is the function of LCAT?
Convertes cholesterol into cholesterol esters in HDL particles for storage in HDLs
What is the receptor on the liver that binds to Apo A1 on HDL particles for uptake?
SRBI
What lipoprotein has the apolipoprotein AI on it? What is its function?
HDL, chylomicrons
Activates LCAT
Ligand for SRB1 receptor
What lipoprotein has the apolipoprotein A-II on it? What is its function?
HDL, chylomicrons
Structural protein for HDL
What lipoprotein has the apolipoprotein B-48 on it? What is its function?
Chylomicrons
Structural protein
What lipoprotein has the apolipoprotein B100 on it? What is its function?
VLDL, IDL, LDL
Structural protein that binds to LDL receptor
What lipoprotein has the apolipoprotein C-II on it? What is its function?
Chylomicrons, VLDL, HDL
Cofactor for lipoprotein lipase
What lipoprotein has the apolipoprotein E on it? What is its function?
Chylomicrons, VLDL, IDL, HDL
Ligand for binding to LDL receptor and remnant
What are the major goals of treating dyslipidemias?
Prevent acute pancreatitis
Prevent CVD
How does endothelial dysfunction lead to the development of CVD?
altered NO biosynthesis
How does injury of dysfunction endothelium lead to the development of CVD?
Expression of adhesion molecules, encouraging monocyte attachment
How does LDL transport into vessel walls lead to CVD?
production of ROS
What are the components of fatty streaks on vessels?
Foam cells
T cells
What is the protective effect of HDL?
Uptake of lipids from arterial walls
What is the inflammatory fibroproliferative response seen in atherosclerosis?
cytokine activation of immune cells leading to deposition of CT
Why are plaque ruptures bad?
Provide a substrate for thrombosis
What are mixed hyperlipidemias?
High cholesterol and TG levels
What is the cause of, and manifestation of: primary chylomicronemia?
Decrease in LPL activity
Increased chylomicron VLDL
What is the cause of, and manifestation of: familial hypertriglyceridemia?
Impaired removeal of VLDL and/or chylomicrons
Increased VLDL/chylomicrons
What is the cause of, and manifestation of: Familiaal combined hyperlipoproteinemia
Increased VLDL production
Increased VLDL
What is the cause of, and manifestation of: familial dysbetalipoproteinemia?
Decreased clearance of VLDL, IDL and chylomicrons
Increased above
What is the cause of, and manifestation of: familial hyper-cholesterolemia?
LDLR impairments
Increased LDL
What is the cause of, and manifestation of: familial ligand-defective apoB?
Mutation in apoB, resulting in impaired endocytosis of LDL
Increased LDL
Major or minor risk factor for atherosclerosis: low HDL
Major
Major or minor risk factor for atherosclerosis: elevated LDL
Major
Major or minor risk factor for atherosclerosis: high triglycerides
Minor
Major or minor risk factor for atherosclerosis: VLDL and IDL remnatns
minor
What is the general MOA of fibric acid derivatives?
PPAR activators
What happens to plasma triglyceridea when using fibric acid derivatives? HDL?
Decreased triglycerides
Increased HDL
What are the two fibric acid derivatives?
Gemfibrozil and fenofibrate
What is the MOA of gemfibrozil?
PPAR activators
What is the MOA of fenofibrate?
PPAR activator
What is PPAR alpha and how do fibratesuse this to treat hyperlipidemia?
transcription factor that increases the expression of lipoprotein lipase, Apo AI, AII, and decreases inhibitor apoprotein C-III
What is the effect of the upregulation of apoA-I and apoA-II proteins by fibrate activation of PPARs?
Increase HDL
What is the effect of the downregulation of apoC-III proteins by fibrate activation of PPARs?
Increase FA uptake
What is the effect of the upregulation of LPL proteins by fibrate activation of PPARs?
Increase FA uptake and breakdown
What is the major adverse effec of combining fibrates with statins?
Myopathy
What is the MOA of chloestyramine?
Bind to bile acids in the intestines, causing increased synthesis of bile acids
What is the MOA of colesevelam?
Bind to bile acids in the intestines, causing increased synthesis of bile acids
What is the MOA of colestipol?
Bind to bile acids in the intestines, causing increased synthesis of bile acids
What happens to the liver when bile acid-binding resins are used?
Increased LDL receptor to increase the uptake of LDL by the liver for bile acid synthesis
What is the major adverse efect of bile-acid binding resins?
Tend to increase plasma triglycerides
What is the drug of choice for pregnant women for treating hypercholesterolemias? Why?
Cholesterol binding resins since they are not absorbed
What is the MOA of niacin for treating dyslipidemias?
Binds to GPCR on adipocytes, decreasing hormone sensitive lipase activity
What is the function of hormone sensitie lipase?
Incrase lipolysis during fasting states when activation by epi, or other hormones
What are the adverse symptoms of Niacin?
Hyperuricemia
Hepatotoxicity
How does niacin increase HDL levels?
Increaseing levels of apo AI
What is the MOA of ezetimibe?
Blocks intestinal absorption of cholesterol by inhibiting NPC1 protein
What is the effect on the liver of ezetimibe use?
Increases LDL receptors
What are the adverse effects of ezetimibe?
Few, if any
What is the MOA of all of the statins?
Competitive inhibitor of HMG-CoA reductase
What is the least potent statin?
Fluvastatin
What are the two most potent statins?
Rosuvastatin
Atorvastatin
What is the effect of statins on the liver? Why?
Increases LDL receptor
Attempt to obtain more cholesterol from the plasma
What are the pleotropic effects of statins?
Whole bunch of good things
What are the adverse effects of statins?
Myopathy
Rhabdo
Hepatotoxicity
What are the labs that are commonly elevated with statin use? When are these concerning?
LFTs
Concerning if bili rises as well
True or false: statins are contraindicated in pregnancy
True
What is niacin used in the treatment of?
All triglycerideemias and hypercholesterolemias
What are resins used to treat?
Familiar hypercholesterolemias
What is the drug of choice for treating familial dysbetalipoproteinemia?
Fibrates
What is the drug of choice for treating primary chylomicronemia?
Fibrates