MODULE 5 PART 2: ROLE OF INFLAMMATION - VASOACTIVE MOLECULES

Question 1

What are the 5 cardinal signs of acute inflammation?

Answer 1

1. Redness
2. Heat
3. Pain
4. Swelling
5. Loss of function

Question 2

Explain the mechanism of inflammation.

Answer 2

Tissue damage –> decreased blood flow in capillaries –> leukocytes adhering to blood vessels –> dilation of small blood vessel in damage area due to vasoactive molecules released by mast cells, damaged tissues, and nerves –> increased blood flow in damaged tissue/vasodilation –> leakage of fluid from blood vessels –> edema & swelling

Question 3

This is the most important vasoactive molecule released by mast cells.

Answer 3

Histamine

Question 4

Histamine binds to what receptors expressed on various cells?

Answer 4

H1 and H2 receptors

Question 5

What happens when histamine binds to H1 receptor?

Answer 5

Stimulates endothelial cell –> conversion of L-arginine –> Nitric oxide –> Potent vasodilator

Question 6

What are the vasoactive molecules released by mast cells ?

Answer 6

1. Histamine
2. Inflammatory lipids
3. Enzymes
4. Vasoactive lipids
5. Vasoactive polypeptides

Question 7

A vasoactive enzyme that activate receptors of mast cells, sensory nerve endings, vascular endothelial cells and neutrophils by making the blood vessels become sticky which is further enhanced by PAF released by neutrophils.

Answer 7

Tryptases

Question 8

What are the vasoactive enzymes released by mast cells?

Answer 8

• Tryptases
• Chymase

Question 9

What is the first triggering effect when there is damaged or stimulated tissues using its phospholipases that acts on cell wall phospholipids?

Answer 9

Release of arachidonic acid

Question 10

Release of arachidonic acid from damaged/stimulated tissues has 2 pathways. What are these?

Answer 10

• Arachidonic acid converted to leukotrienes by 5-lipoxygenase
• To prostaglandins by cyclooxygenase

Question 11

This vasoactive lipid stimulates the neutrophil, eosinophil chemotaxis and motility; also increases vascular permeability.

Answer 11

Leukotrienes

Question 12

Type of prostaglandin found in platelets

Answer 12

Thromboxanes

Question 13

Type of prostaglandin found in vascular endothelial cells

Answer 13

Prostaglandins

Question 14

This vasoactive polypeptide promote histamine release from mat cells and cause blood vessel dilation and leakage.

Answer 14

Anaphylatoxins

Question 15

This vasoactive polypeptide causes blood vessel dilation and leakage, stimulate neutrophils and trigger pain receptors.

Answer 15

Kinins

Question 16

What is the most important kinin?

Answer 16

Bradykinin