Dyslipidemia

Question 1

How does our body solve the insoluble fat issue? (ie, we want fats to be soluble, but because they’re hydrophobic they float instead of dissolving, how do we solve this?)

Answer 1

• the body wraps the fat in a lipophilic membrane

- inside of the membrane is lipophilic, outside is hydrophilic

Question 2

What makes up a lipid?

Answer 2

• the core: triglycerides and cholesteryl esterase

- the outside: phospholipids and cholesterol

Question 3

Put the following in size order: LDL, HDL, chylomicron, VLDL, IDL

Answer 3

• HDL

Question 4

Apolipoprotein

Answer 4

• proteins with specific “instructions” that are added to the lipophilic membrane

Question 5

What does the liver secrete in response to ingested fats? What role do these products have?

Answer 5

• liver secretes bile acids and cholesterol
• these target the ingested lipids and direct them towards the capillaries where their fatty acids can be absorbed
• the remnant of the fat is then directed towards the liver to be broken down

Question 6

HDL

Answer 6

• high-density lipoprotein
• “mops up” free floating cholesterol from macrophages and peripheral cells
• has apoprotein ApoA-1 or ApoA-2

Question 7

Why aren’t chylomicrons involved in atherosclerosis?

Answer 7

• because they are FAR too large

Question 8

LDLR

Answer 8

• receptors on the liver that bind to LDL molecules, resulting in their uptake into the liver

Question 9

Statins

Answer 9

• used to manage LDL cholesterol levels
• mechanism: inhibits HMG-CoA reductase (enzyme involved in cholesterol biosynthesis), fooling the body into thinking there is a lack of cholesterol and resulting in the increased uptake of the body’s LDL
• effects: decreased cholesterol synthesis, increased LDLR synthesis = decreased LDL levels

Question 10

Ezetimibe

Answer 10

• a cholesterol absorption inhibitor
• mechanism: binds to NPC1L1, preventing cholesterol uptake by the liver, resulting in an increase in LDLR syntehsis (thus lowering the circulating LDL levels)