Lipoprotein 2

Question 1

What happens in Carnitine Palmitoyl-CoA Transferase II deficiency?

Answer 1

CPTII is the enzyme that conjugates FA to form acyl-CoA to acyl-carnitine which is then transferred back to mitochondria where the acyl is transferred back onto the CoA - the transferase does not work so things like palmitate cannot be made
Most common inherited disorder of FA oxidation

Question 2

Type I hyperlipidemias

Answer 2

Accumulation of chylomicrons, LPL or apoCII deficiency

Question 3

Type II hyperlipidemias

Answer 3

Elevated LDL levels, genetic defects in LDL receptor
Hetero - high LDL
Homo - myocardial infarction before age 20

Question 4

Type III hyperlipidemias

Answer 4

Abnormal apoE, interferes with uptake of chylomicron and VLDL uptake
Hypothyroidism has similar effects

Question 5

Type IV hyperlipidemias

Answer 5

VLDL inc due to obesity, alcohol abuse or diabetes
Most common
Also has genetic form

Question 6

Type V hyperlipidemias

Answer 6

Similar to type I, inc VLDL production, high chylomicrons

Can lead to pancreatitis, eruptive xanthomas

Question 7

Hypercholesterolemia

Answer 7

Biliary excretion is reduced

Abnormal lipoprotein X will accumulate

Question 8

What is olestra?

Answer 8

A sucrose molecule with fatty acids attached to the -OH
Fat substitute
Too large to digest- no calories

Question 9

What is the problem with olestra?

Answer 9

Causes absorption of lipid soluable vitamins (A, D, K ,E)
Causes digestion problems
Anal leakage

Question 10

What is an advantage to olestra?

Answer 10

Can remove dioxins

Effective for long term weight loss in obese patients

Question 11

What is orlistat?

Answer 11

Strong inhibitor of pancreatic lipase
Isolated from stretomyces
Saturated form of lipstatin
Makes you feel fuller longer

Question 12

How does dietary fat and cholesterol influence plasma liproteins?

Answer 12

Inc saturated fats circulating, inc LDL CH levels
Omega 6-PUFA lowers circulating CH
Omega 3-PUFA lowers circulating TGs

Question 13

How does fiber influence plasma liproteins?

Answer 13

Insoluble fiber has limited effects on circulating CH

Soluble fiber has an effect on lowering CH

Question 14

What are the three proposed mechanism of fiber?

Answer 14

1. Bile acid sequestration
2. Reduce insulin rise - slow CHO absorption
3. May produce short chain FAs - reduce Ch synth

Question 15

How does protein and alcohol influence plasma liproteins?

Answer 15

Inc animal protein - inc circulating CH

Red wine - lower levels of LDLs high HDLs

Question 16

How are arterial plaques formed?

Answer 16

Macrophages uptake oxidative modified or damaged LDLs, become engorged with fat, and become foam cells

Question 17

What are some reactive oxygen species due to oxidation of lipids?

Answer 17

Superoxide, Hydroxyl radical, H2O2

Question 18

Why are lipid peroxides LOOH so dangerous? And what are they called?

Answer 18

Very toxic, unstable and can’t be absorbed well

Lipofuscins

Question 19

What are isoprostanes?

Answer 19

Non-enzymatically produced eiconsanoids due to random oxidation of phospholipids

Question 20

What does apoB-100 do?

Answer 20

VLDL assembly and secretion
Structural part of VLDL, IDL, LDL
Ligand for LDL receptor
In the liver

Question 21

What does apoE do?

Answer 21

Ligand for several lipoproteins to LDL receptor
LDL receptor-related protein (LRP)
In the liver

Question 22

What is the genetic treatment for hyperlipidemia?

Answer 22

Statin drugs but primarly apolioprotein E (apoE)
Nonviral treatment
Cell based therapy
in vivo apoE-secreting ‘mini-organs’