Flashcards in Vitamin E Deck (25)
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1
what two classes is vitamin E divided into
1. tocopherols (saturated)
2. tocotrienols (unsaturated)
2
what is the most biologically active form of vitamin E
RRR alpha-tocopherol (D-alpha-tocopherol)
3
individuals on __ diets may inadvertently limit their vitamin E uptake
low-fat
4
the in enterocyte, vitamin E is incorporated into ___ for transport through the lymphatic system ultimately reaching the circulation
chylomicrons
5
______ remnants deliver vitamin E to the liver using receptor mediated endocytosis
chylomicron
6
discrimination between the different vitamer forms of vitamin E does not occur during their absorption into the ______
small intestine or in their packaging into chylomicrons
7
in the liver RRR-alpha-tocopherol is incorporated into ___ for transport to the extrahepatic tissues
VLDL's
8
a specific protein called _______ ,which is made in the liver, mediates the transfer of RRR-alpha-tocopherol into the VLDL's
alpha-tocopherol transfer protein
9
the liver will secrete the other forms of vitamin E into the ____ via bile
feces
10
____ can interfere with the enzymes of vitamin K cycle
tocopherol quinone
11
oxidation of the phytyl tail by W and beta-oxidation lead to products called
alpha-carboxyethyl-hydroxychroman (alpha-CEHC)
12
high intakes of vitamin E can interfere with all other fat soluble vitamins like
beta-carotene
13
vitamin E can block the regeneration of the reduced form of vitamin ___, and thereby interfering with blood coagulation
K
14
why do some physicians recommend discontinuing vitamin E before surgery
risk of hemorrhaging
15
what 3 routes does RRR-alpha-tocopherol get to extrahepatic tissues
1. LDL receptor mediated endocytosis
2. lipoprotein lipase mediated uptake from VLDLs
3. phospholipid transfer protein (PTP) facilitates vitamin E transfer from lipoproteins to cell phospholipid membrane
16
within cytoplasm of the cell, vitamin E ca bind to a specific tocopherol binding protein called
adenosine triphosphate binding cassette A1 (ABC A1)
17
tocopherol -> ___ -> tocopheroxyl radical
ascorbate glutathione or ubiquinone
18
vitamin E can inhibit protein kinase C by
dephosphorylation via activation of a specific protein phosphatase (PP2A)
19
how does vitamin E inhibit heard disease and stroke
1. decrease LDL oxidation and decrease macrophage uptake
2. decrease protein kinase C activity
3. decrease monocyte endothelial adhesion
4. decrease scavenger receptor expression: decrease oxidized LDL uptake
5. decrease alpha-tropomyosin expression: decrease smooth muscle hypertrophy
6. decrease monocyte SOD activity
7. increase NO production: increase arterial dilation
8. increase PGI2: decrease TXA2: increase vasodilation: decrease platelet aggregation
9. increase carboxyethyl-hydroxychroman CEHC: decrease blood pressure
20
what 4 positive functions do tocotrienols have
1. suppress activity of HMG-CoA reductase: reduce cholesterol synth
2. increase HMG-CoA reductase degradation and decrease efficiency of translation of HMG-CoA reductase mRNA
3. suppressed tumor cell angiogenesis
4. prevent glutamate induced neurotoxicity (parkinsons and alzheimer's)
21
what are the three increasing apoptosis mechanisms of gamma-tocotrienol
1. increased pro-apoptotic BAX expression
2. decreased anti-apoptotic BCL-2 expression
3. decreased the oncogene Myc expression
22
vitamin E is shown to reduce the incidence of prostate cancer
T
23
there are no trials seen of vitamin E providing benefiting effects to those with parkinsons and alzheimers
T
24
vitamin E when taken with food may prevent heart disease, but no evidence it is preventative when taken it as a supplement
T
25
