*Pharmacology - lecture 5 (science, drugs are in table) Flashcards Preview

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Flashcards in *Pharmacology - lecture 5 (science, drugs are in table) Deck (47)
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1

Are lipids soluble or insoluble in water?

Insoluble (or sparingly soluble)

2

Purpose of lipids?

Essential for membrane biogenesis and membrane integrity
Energy sources, precursors for hormones and signalling molecules

3

How are non-polar lipids (e.g. cholesterol esters and triglycerides) transported in blood?

Within lipoproteins e.g. high density lipoproteins, low density liporpteins

4

In terms of HDL and LDL, what is CV disease strongly associated with?

Elevated LDL
Decreased HDL

5

What causes elevated LDL and decreased HDL?

Diet and lifestyle (particularly western)
Genetic factors (e.g. familial hypercholestrerolaemia)

6

What are the 2 parts of a lipoprotein?

Hydrophobic core
Hydrophilic coat

7

What is found within the hydrophobic core of a lipoprotein?

Esterified cholesterol and triglycerides

8

What is the hydrophilic coat of a lipoprotein composed of?

Monolayer of amphipathic cholesterol, phospholipids and one, or more, apoproteins (apo)

9

What are the major lipoproteins? (4)

HDL particles
LDL particles
Very-low density lipoprotein particles
Chylomicrons

10

What apoproteins do HDL proteins contain? (2)

apoA1 and apoA2

11

What apoprotein does LDL particles contain?

apoB-100

12

What apoprotein does very-low density lipoprotein particles contain?

apB-100

13

What apoprotein does chylomicrons contain?

apoB-48

14

What is the purpose of apoB-containing lipoproteins?

Deliver triglycerides to muscle for ATP biogenesis and adipocytes for storage

15

Where are chylomicrons formed?
What do they carry?
What is this pathway called?

In intestinal cells
Transport dietary triglycerides
Exogenous pathway

16

Where are VLDL formed?
What do they carry?
What is this pathway called?

Liver cells
Triglycerides synthesised in that organ
Endogenous pathway

17

What are the 3 stages of the life cycle of an ApoB-containing liposome?

Assembly
Intravascualr metabolism
Receptor mediated clearance

18

Where does the majority of the bodies cholesterol come from?

75% = liver
25% = diet

19

What happens to an chylomicron formed within the endoplasmic reticulum of an enterocyte?

It exits the enterocyte by exocytosis following the addition of a second apoprotein (apoA1), enters lymphatics and is carried in lymph to systemic circulation (subclavian vein) via the thoracic duct

20

What are VLDL particles containing triglycerides assembled in the liver hepatocytes from?

Free fatty acids derived from adipose tissue (particularly during fasting) and de novo synthesis

21

What must happen to activate chylomicrons and VLDL particles allowing them to target triclyceride delivery to adipose and muscle tissue?

They must be activated by by the transfer of apoCII from HDL particles

22

What is the name of the enzyme that is associated with the endothelium of capillaries in adipose and muscle tissue?

Lipoprotein lipase (lipolytic enzyme)

23

What facilitates the binding of chylomicrons and VLDL to LPL on the endothelium of capillaries in adipose and muscle tissue?

ApoCII

24

What does lipoprotein lipase do?

Hydrolyses core triglycerdies to free fatty acids and glycerol which enter tissues

25

What is name of particles depleted of triglycerides (But still containing cholesterol esters)?

Chylomicron and VLDL remnants

26

Why do chylomicrons and VLDL particles become relatively enriched in cholesterol?

Due to triglyceride metabolism due to LPL

27

What happens to ApoCII when the chylomicrons and VLDL dissociated from LPL?

It is transferred to HDL particles in exchange for apoE which is high affinity ligand for receptors mediated clearance - particles are now remnants

28

What happens to remnants?

They return to the liver and are further metabolised by hepatic lipase - all apoB48-containing remnants and 50% of apo100 containing remnants are cleared by receptor-mediated endocytosis into hepatocytes - remaining apoB100-containing remnants loose further triglyceride through hepatic lipase, come smaller and enriched in cholesterol ester and via intermediate density lipoproteins (IDL) become LDL particles asking ape and retaining solely apoB100

29

What is the most important place of LDL particle clearance?

the liver

30

Where is the most important site of LDL clearance?

Liver