Cardiology: Lipid Metabolism

Question 1

Describe the structure of a lipid protein.

Answer 1

Hydrophobic cholesterol ester centre.

Hydrophyllic coat of phospholipid, cholesterol and apoproteins

Question 2

Which apoproteins are associated with chylomicrons?

Answer 2

Apo B48

Question 3

Which apoproteins are associated with HDL?

Answer 3

Apo A1 and A2

Question 4

Which apoproteins are associated with LDL?

Answer 4

Apo B100

Question 5

Which apoproteins are associated with VLDL?

Answer 5

Apo B100

Question 6

What is the purpose of Apo B lipoproteins?

Answer 6

Deliver tryglerides to muscles for ATP synthesis and for storage in adipocytes.

Question 7

Where are chylomicrons formed?

Answer 7

Intestine

Question 8

Where are VLDL formed?

Answer 8

Liver

Question 9

What is the name of the receptor that allows cholesterol into the enterocyte during chylomicron formation?

Answer 9

Niemann Pick C1 like protein

NPC1L1

Question 10

what mediates lipidation of chylomicrons?

Answer 10

MTP (microsomal tryglyceride transfer protein)

Question 11

Where do chylomicrons travel after exiting the enterocyte?

Answer 11

Thoracic duct then subclavian vein

Question 12

How are chylomicrons and VLDL activated?

Answer 12

Transfer of apo Cll from HDL

Question 13

How are apoB proteins cleared?

Answer 13

They disocciate from LPL and ApoCll is transferred back to HDl in exchange fro apoE.
Return to the liver and are metabolised by hepatic lipase.
All apo B48 and half apoB100 are cleared by endocytosis of hepatocytes.
ApoB100 become LDL via IDL.
They now lack apoE.

Question 14

What cholesterol causes atheromas?

Answer 14

LDL

Question 15

What is the role of HDL in the body?

Answer 15

Removes excess cholesterol from cells by transporting it to the liver

Question 16

Describe the process of atheroma formation.

Answer 16

Epithelial damage
Uptake of LDL into endothelium-->OXLDL
Macrophages uptake OXLDL resuting in a fatty streak
Collagen is layed down.
Atheromatous plaque is formed.

Question 17

What is primary dyslipidemia?

Answer 17

Dietary and genetic cause of lipid profile

Question 18

What is secondary dislipidemia

Answer 18

Consequence of disease eg diabetes, alcoholism, liver disease

Question 19

What lipoprotein is elevated in type 1 primary dyslipidemia?

Answer 19

chylomicrons

Question 20

Type IIa?

Answer 20

LDL

Question 21

Type IIb

Answer 21

LDL and VLDL

Question 22

Type III

Answer 22

beta VLDL

Question 23

Type IV

Answer 23

VLDL

Question 24

Type V

Answer 24

chylomicrons and VLDL

Question 25

Name two statins.

Answer 25

Simvastatin | Atorvastatin

Question 26

What are statins?

Answer 26

HMG coA reductase inhibitora

Question 27

What do statins prevent the production of?

Answer 27

Mavalonate and thus cholesterol

Question 28

What effect does the decrease in cholesterol cause?

Answer 28

Increased LDL receptor expressiona nd enhanced clearing of LDL

Question 29

What are the other additional benefits of statins?

Answer 29

Decreased inflammation Reversal of endothelial dysfunction Decreased thrombosis Stabilization of atheromatous plaques

Question 30

Give the adverse affects of statins

Answer 30

Myosiitis and rhabdomyolosis

Question 31

Name two fibrates.

Answer 31

Bezafibrate | Gemfibrozil

Question 32

When would you use a fibrate?

Answer 32

First line in patients with very high tryglyceride levels

Question 33

Which group of people should fibrates be avoided

Answer 33

Alcoholics

Question 34

Give the adverse effect of fibrates

Answer 34

``` Myositis Rhabdomyolosis Gi symtoms Pruritus Rash ```

Question 35

What drugs inhibit cholesterol absorptions

Answer 35

Bile acid binding resisn

Question 36

Name three bile acid binding resins

Answer 36

Colestryamine Colestipol Colsevelam

Question 37

How do bile acid binding resins work?

Answer 37

Inhibit the reabsorption of bile salts So more cholesterol must be converted to bile salts Decreased absoprtion of triglycerides Increased LDL receptor expression

Question 38

Give the adverse affect of bile acid binding resins

Answer 38

Adverse GI irritation

Question 39

What is ezetimibe

Answer 39

Inhibits the Niemann Pick C1 transport protein

Question 40

What effect does ezetimibe have on the lipid profile

Answer 40

Decreased LDL | LIttle change to HDL

Question 41

When is ezetimibe used?

Answer 41

In combo with a statin when the latter does not give adequate reponse

Question 42

Give the adverse effects of ezetimibe

Answer 42

Diarrhoea, abdo pain , headache

Question 43

When is ezetimibe contraindicated

Answer 43

Breast feeding females