Flashcards in Nutrition Module 11: CVD - Lipoproteins Deck (55)
Where do most of the FAs in the body come from?
What are the 3 atherogenic lipoproteins?
1. Chylomicron remnants
3. VLDL remnants
What are the 3 non-atherogenic lipoproteins?
What do people who cannot produce chylomicrons due to genetic defects usually suffer from? Why? Treatment?
Neuropathy because neurons lack vitamin E
Treatment: VE injections or oral doses that are thousand fold higher than normal
Describe the route of chylomicrons (5 stops)
3. Adipose tissue
4. Hepatic artery
How fast are chylomicrons cleared from the bloodstream? What determines the rate of clearance?
Genetics and dietary habits (high/low-fat)
How does the amount of fat eaten in a typical american meal affect the rate of clearance of chylomycrons? How does this affect atherosclerosis risks?
The amount of fat saturates the clearance pathway which prolongs their circulation causing increased atherosclerosis risks
What is an independent risk factor of CVD?
Elevation of serum TAGs
What can high TAGs be caused by?
2. Lack of PA
3. High carbs
What 3 molecules do VLDLs transport?
3. Vitamin E
Which is faster: chylomicrons or VLDL TAG hydrolysis?
What is the main difference between chylomicron and VLDL remnants?
Chylomicron remnants are all cleared by receptor-mediated endocytosis vs only half of VLDL remnants are cleared like this
Which have longer half-lives: chylomicrons or VLDLs?
What is fatty liver? What is it caused by?
Chronic alcohol abuse impairs the liver from exporting excess TAGs via VLDLs = TAGs accumulate
What is the half-life of LDLs?
Which lipoproteins mediate the transport of cholesterol from arterial walls into the liver?
2 components of LDLs?
2. Vitamin E
What is cellular LDL cholesterol uptake regulated for?
To ensure adequate supply of cholesterol for the synthesis of membranes, hormones, and other critical compounds
What causes slowed LDL uptake?
Cells have enough cholesterol => fewer receptors are expressed especially on liver => LDL receptor down-regulation
How does dietary cholesterol intake affect the liver? What is the net effect?
Down-regulation of liver LDL receptors = high serum LDL = harder for liver to excrete as bile
Which cells have the highest LDL receptor activity?
Adrenal gland cells
Does the liver have to convert cholesterol into bile acids before it goes into bile?
What kinds of FAs can lower LDLs?
Polyunsaturated FAs (eg: omega-3 FAs)
What kinds of FAs can increase LDLs?
Saturated and trans FAs
What kinds of FAs have no effect on LDL levels?
What are the 4 factors that influence LDL levels?
2. Body weight
By what % can lifestyle changes reduce excessive LDL levels?
Other than polyunsaturated FAs, what 5 other foods can lower LDL levels?
1. Viscous dietary fiber
2. Soy protein
3. Plant stanols and sterols
What 4 foods are viscous fibers found in?