29. Biochemistry of Surfactant

Question 1

Name the major cell types in the lung

Answer 1

Smooth muscle
Macrophages
Mast cells
Goblet cells
Submucosal glands
Endothelial cells
Type 1 and 2 pneumocytes

Question 2

What effect does surfactant have on compliance?

Answer 2

Increases compliance

Question 3

What is surfactant composed of?

Answer 3

40% DPPC
40% other phospholipids
5% surfactant associated proteins
Cholesterol

Question 4

What two ways can phospholipids be synthesised?

Answer 4

Donation of phosphatidic acid from CDP-diacylglycerol to an alcohol
or
Donation of the phosphomonoester from CDP-alcohol to 1,2-diacylglycerol

Question 5

What is the side product of phospholipid synthesis?

Answer 5

CMP

Question 6

What enzyme catalyses phospholipid synthesis?

Answer 6

Phosphatidic acid phosphatase

Question 7

What are the 4 surfactant associated proteins?

Which are hydrophilic and which hydrophobic?

Answer 7

SP-A (hydrophilic)

• B (hydrophobic)
• C (hydrophobic)
• D (hydrophilic)

Question 8

How is foetal lung maturity tested?

Answer 8

Sampling the amount of surfactant in amniotic fluid by amniocentesis

1. Lecithin-sphingomyelin ratio
2. Phosphatidylglycerol
3. Surfactant/albumin ratio

Question 9

What does a Z-mutation of alpha-1-antitrypsin lead to?

Answer 9

Deficiency of AAT in the lung

Question 10

What does an S-mutation lead to?

Answer 10

Reduced serpin activity

Question 11

What does a Pittsburg mutation lead to?

Answer 11

AAT converted to a thrombin inhibitor

Clotting disorder