Lipoproteins

Question 1

what disorder is caused by ApoB truncations

Answer 1

hypobetalipoproteinemia

Question 2

what is the consequence of truncated ApoB

Answer 2

secreted slower and cleared faster

Question 3

what are the hypobetalipoproteinemia heterozygote LDL levels

Answer 3

25-50% of normal

Question 4

what are the consequences of hypobetalipoproteinemia

Answer 4

tseato-hepatitis, and homozygotes get fat soluble vit deficiency and nueromuscular degeneration

Question 5

where are VLDLs with truncated ApoB cleared?

Answer 5

renal tubule

Question 6

abetalipoproteinemia is caused by

Answer 6

MTP definceicy

Question 7

what does MTP do?

Answer 7

transport TG’s and cholesterol esters onto ApoB to form VLDL

Question 8

which 2 conditions are caused by excessive ApoB synthesis in the liver?

Answer 8

Familial combined hyperlipidemia and hyperbetalipoproteinemia

Question 9

what does Hyperapobeta look like

Answer 9

dense ApoB-100 LDL with too much apo B

Question 10

what does FCHL look like

Answer 10

increased number of normal VLDL

Question 11

how can there be an accumulation of normal LDL in FCHL and hyperapobeta

Answer 11

defect in LDL clearance in addition to excess VLDL production

Question 12

Is apoB production normally constant

Answer 12

yes

Question 13

how is more lipid normally transported

Answer 13

bigger particles

Question 14

what happens in familial hypertriglyceridemia

Answer 14

high liver TG synthesis, TG plasma concentration, and TG/apoB ratio

Question 15

what FHT patients tend to get CVD

Answer 15

those with a family history of CVD

Question 16

is HDL low or high in all FHT

Answer 16

low

Question 17

what are FHT + CAD patients likely to have

Answer 17

insulin resistance

Question 18

what things raise VLDL or TG production

Answer 18

dietary fat, visceral fat, high glucose, fructose, and alcohol

Question 19

why are visceral adipocytes bad

Answer 19

they release alot of free fatty acids

Question 20

what leads to visceral fat

Answer 20

hyperandrogenism in women, hypoandrogenism in men, and hypercortisolism

Question 21

what do saturated fatty acids do

Answer 21

stimulate cholesterol synthesis and down regulate LDL receptors

Question 22

what does LPL do

Answer 22

hydrolyzes CLDL and CM to free fatty acids is adipose cells, muscle cells, and macrophages

Question 23

what is required for LPL

Answer 23

ApoCII

Question 24

what inhibits LPL

Answer 24

ApoCIII

Question 25

what does a deficiency of LPL of ApoCII do

Answer 25

severe hypertriglyceridemia

Question 26

what does LPL biosynthesis require

Answer 26

small amount of insulin

Question 27

what is Type I HLP

Answer 27

only high chylomicrons

Question 28

what is Type V HLP

Answer 28

high VLDL and chylomicrons. clear cream and foggy plasma

Question 29

what are the only things that cause Type I HLP

Answer 29

deficiency of LPL or ApoCII

Question 30

what causes Type V HLP

Answer 30

VLDL over production and slight LPL abnormality

Question 31

when is ApoCIII elevated

Answer 31

insulin resistance

Question 32

does plasma TG correlate better with ApoCII or ApoCIII

Answer 32

ApoCIII

Question 33

where is ApoE synthesized

Answer 33

liver. macrophages, and CNS

Question 34

when is apoE secreted by macrophages

Answer 34

along with cholesterol

Question 35

what is the main function of apoE

Answer 35

clearing remnants of lipoproteins

Question 36

where is apoE kept

Answer 36

on HDL and then transferred to other particles

Question 37

what protein prevents apoE from removing CMs and VLDL too soon

Answer 37

apoCIII

Question 38

why to larger particles not bind apoE

Answer 38

the binding site is covered by lipid

Question 39

how does apoE bind

Answer 39

charge interaction

Question 40

what apoE phenotype is seen in familial dysbetalipoproteinemia

Answer 40

E2/E2

Question 41

what do E2 heterozygotes get

Answer 41

low LDL and high TG without the disease

Question 42

what do E4 people get

Answer 42

high LDL