Lipids (Exam 4) Flashcards
________ are the major forms of circulating cholesterol
cholesterol esters and triglycerides
Cholesterol esters & triglycerides are ______(soluble/insoluble) in water.
Insoluble
_______ form when proteins and phospholipids form complexes with cholesterol esters/ triglycerides.
Lipoproteins
Metabolism of lipoproteins can take one of two pathways; exogenous or endogenous. Which pathway is the absorption of dietary fat from food which is then distributed to muscle, adipose and the liver?
Exogenous
Which lipoprotein metabolism pathway is associated with the synthesis of VLDL by the liver, which then delivers cholesterol and triglycerides to the tissues in fasting state?
Endogenous
___ ____ ______ deliver cholesterol to tissues–gonads, adrenals, and rapidly dividing cells. Their coat is made up of ______.
Low density lipoproteins
phospholipids & apolipoprotein B-100 (APO-B)
Low density lipoproteins are removed from the blood stream via the ________; via LDL receptor, but can also be removed via the non-LDL-receptor-mediated- pathway via _________ cells, smooth muscle cells, and macrophages, which leads to plaque growth.
Liver
Kupffer
LDL’s are ________(small/large), making them _______(highly/not very) atherogenic
Small
Highly atherogenic
(Small density LDL’s are even more atherogenic)
There are ____ subclasses of LDL’s (all based on density differences).
7
Each has own LDL particle number.
If normal ____ and _____ LDL particle, pt is at increased risk for CAD.
LDL
HIGH
This type of lipoprotein has a protective effect against atherosclerosis via the “Reverse Cholesterol Transport” system and
Helps clear excess cholesterol from circulation
High density lipoprotein
Where are HDL’s made?
liver and intestine
HDL’s coats are made of 50% _________, 20% __________, and sub-fractions of HDL2 and HDL3.
50% apoprotein (A-1 & A-II)
20% cholesterol
**NOTE: HDL2 may be more protective due to greater cholesterol content, by reversing cholesterol transport.
This lipoprotein is a variation of LDL, but is more atherogenic/ “sticky” than LDL.
Lipoprotein A
Lipoprotein A [Lp(a)] is made of Two components:
LDL-like particle with __________ &
a hydrophilic protein called ___________.
Apoprotein B
Apoprotein A
____________ is structurally close to plasminogen and May cause aggravation of the thrombolytic system leading to clot formation.
Apoprotein A
We see ______ Lp(a) in nephrotic kidney disease, but ______ Lp(a) in dialysis pts.
Higher
Lower
\_\_\_\_\_\_\_\_\_\_ is a complex process involving: Endothelial dysfunction Dyslipidemia Inflammatory and Immunologic factors Plaque rupture Smoking
Atherosclerosis
Name the 3 layers of blood vessel lining from innermost to outermost.
Intima
Media
Adventitia
The ______ layer of the blood vessel is lined with endothelial cells that release nitric oxide.
Intima
Endothelial dysfunction is an initial step in atherosclerosis, and is thought to be caused by ________________________.
This dysfunction is particularly induced by ______ LDL.
loss of endothelium-derived nitric oxide
Oxidized
True or false?
Endothelial dysfunction has nothing to do with the traditional risk factors of atherosclerosis (i.e. HTN, DM, tobacco use, etc)
FALSE
Endothelial dysfunction is associated with many of the traditional risk factors: hypercholesterolemia, diabetes, hypertension, and tobacco use
What is the number one treatment used for endothelial dysfunction?
STATINS
NOTE: Can be Improved by: correction of hyperlipidemia which increases the bioavailability of nitric oxide HLD tx’d by: diet or by medication
ACE inhibitors
High doses of antioxidants (Vit C, red wine, grapes)
However, clinical benefits of these therapies have only been demonstrated convincingly for statins.
Dyslipidemia (Aka: hyperlipidemia or hypercholesterolemia) is characterized by: \_\_\_\_\_\_ LDL \_\_\_\_\_\_ HDL \_\_\_\_\_\_ Triglycerides
Elevated
Low
Elevated
LDL becomes elevated when LDL is _______ and then taken up by macrophages lining the ________ ________.
oxidized
arterial intima
Macrophages that are “lipid laden” are called ____ _____, which bury in the intimal lining of the arteries to eventually form plaque
Foam cells
TRUE OR FALSE?
Oxidation of LDL causes changes in vascular tone, induction of growth factors, increased platelet aggregation and the formation of autoantibodies
TRUE
Macrophages that have been modified by oxidized LDL’s, release a variety of _____________ substances.
Inflammatory
they also release cytokines and growth factors
TRUE OR FALSE?
Evidence shows that increased inflammation = increased risk of atherosclerosis.
TRUE
Serum CRP is the BEST STUDIED of the inflammatory markers. ______ (high/low) CRP is consistently associated with atherosclerotic cardiovascular disease, however its fxn as a causal risk factor has not been established.
HIGH/elevated
______ is a high sensitivity CRP test that is more specific for heart disease versus systemic inflammation.
hs-CRP
_______ is a lipoprotein-associated, macrophage-secreted enzyme that perpetuates plaque inflammation.
LpPLA2 (lipoprotein-associated phospholipase A2)
Elevated levels of LpPLA2 predict a 40 to 400 % increased risk of ____ and _______.
MI and stroke
True or false? Cytokines are Anti-inflammatory.
False. They are pro-inflammatory
Why is HTN bad and a major risk factor for the development of atheroclerosis? Name 3 reasons.
- increases arterial wall tension, potentially leading to disturbed repair processes and aneurysm formation
- part of “scuffing” up the arterial wall lining, making divets for plaques to deposit
- Can “pound away” at an atheroma and increase risk of rupture or cause a part to break off and thrombose
Which is more common? Total occlusion of an artery due to plaque OR plaque rupture with thrombus?
Total occlusion of an artery due to plaque growth is not as common as you would think!
Why? The artery grows in diameter to accommodate the occlusive area.
Plaque rupture with thrombus (blood clot) is the more frequent cause of an AMI or ischemic stroke
This conscious habit impairs endothelium-dependent vasodilation (EDV), increases inflammatory markers: CRP, IL-6, and TNF-alpha, increases fibrinogen levels and decreases fibrinolysis, which increases risk of CLOT formation, and increases oxidative modification of LDL.
SMOKING
It’s bad, don’t do it! It impacts ALL phases of atheroclerosis.
DM is another player in atherosclerosis. Clinical and experimental studies suggest that high levels of _______precede development of arterial disease.
Insulin