Lipoprotein 2 Flashcards
What happens in Carnitine Palmitoyl-CoA Transferase II deficiency?
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
Type I hyperlipidemias
Accumulation of chylomicrons, LPL or apoCII deficiency
Type II hyperlipidemias
Elevated LDL levels, genetic defects in LDL receptor
Hetero - high LDL
Homo - myocardial infarction before age 20
Type III hyperlipidemias
Abnormal apoE, interferes with uptake of chylomicron and VLDL uptake
Hypothyroidism has similar effects
Type IV hyperlipidemias
VLDL inc due to obesity, alcohol abuse or diabetes
Most common
Also has genetic form
Type V hyperlipidemias
Similar to type I, inc VLDL production, high chylomicrons
Can lead to pancreatitis, eruptive xanthomas
Hypercholesterolemia
Biliary excretion is reduced
Abnormal lipoprotein X will accumulate
What is olestra?
A sucrose molecule with fatty acids attached to the -OH
Fat substitute
Too large to digest- no calories
What is the problem with olestra?
Causes absorption of lipid soluable vitamins (A, D, K ,E)
Causes digestion problems
Anal leakage
What is an advantage to olestra?
Can remove dioxins
Effective for long term weight loss in obese patients
What is orlistat?
Strong inhibitor of pancreatic lipase
Isolated from stretomyces
Saturated form of lipstatin
Makes you feel fuller longer
How does dietary fat and cholesterol influence plasma liproteins?
Inc saturated fats circulating, inc LDL CH levels
Omega 6-PUFA lowers circulating CH
Omega 3-PUFA lowers circulating TGs
How does fiber influence plasma liproteins?
Insoluble fiber has limited effects on circulating CH
Soluble fiber has an effect on lowering CH
What are the three proposed mechanism of fiber?
- Bile acid sequestration
- Reduce insulin rise - slow CHO absorption
- May produce short chain FAs - reduce Ch synth
How does protein and alcohol influence plasma liproteins?
Inc animal protein - inc circulating CH
Red wine - lower levels of LDLs high HDLs
How are arterial plaques formed?
Macrophages uptake oxidative modified or damaged LDLs, become engorged with fat, and become foam cells
What are some reactive oxygen species due to oxidation of lipids?
Superoxide, Hydroxyl radical, H2O2
Why are lipid peroxides LOOH so dangerous? And what are they called?
Very toxic, unstable and can’t be absorbed well
Lipofuscins
What are isoprostanes?
Non-enzymatically produced eiconsanoids due to random oxidation of phospholipids
What does apoB-100 do?
VLDL assembly and secretion
Structural part of VLDL, IDL, LDL
Ligand for LDL receptor
In the liver
What does apoE do?
Ligand for several lipoproteins to LDL receptor
LDL receptor-related protein (LRP)
In the liver
What is the genetic treatment for hyperlipidemia?
Statin drugs but primarly apolioprotein E (apoE)
Nonviral treatment
Cell based therapy
in vivo apoE-secreting ‘mini-organs’
