BIOCHEMISTRY - Mediators of Inflammation

Question 1

What are the five main groups of acute inflammatory mediators?

Answer 1

Vasoactive amines
Arachidonic acid metabolites
Cytokines
Chemokines
Complement proteins

Question 2

What are inflammatory mediators produced by?

Answer 2

Immune cells
Tissue cells
Liver

Question 3

What are the two main vasoactive amines involved in the immediate, transient, acute inflammatory response?

Answer 3

Histamine
Serotonine

Question 4

Which cell type produces histamine?

Answer 4

Mast cells

Question 5

What are the five possible stimuli for histamine release?

Answer 5

Trauma
Cold
Heat
Binding of IgE antibodies
Anaphylatoxins

Question 6

Which histamine receptor is present on the surface of microvascular endothelial cells?

Answer 6

H1 receptors are present on the surface of microvascular endothelial cells

Question 7

What are the three main roles of histamine in acute inflammation?

Answer 7

Dilation of arterioles
Increased vascular permeability
Eosinophil chemotaxis

Question 8

List an example of a histamine inhibitor

Answer 8

H1 receptor antagonist

Question 9

Which two cell types produce serotonine?

Answer 9

Platelets
Neuroendocrine cells

Question 10

What is the main function of serotonine in acute inflammation?

Answer 10

Vasoconstriction

Question 11

Which group of enzymes release arachidonic acid from cell membrane phospholipids?

Answer 11

Phospholipase enzymes

Question 12

What are the two enzymatic pathways which metabolise free arachidonic acid?

Answer 12

Cyclooxygenase (COX)
Lipoxygenase

Question 13

Which complement protein activates the lipoxygenase pathway?

Answer 13

C5a activates the lipoxygenase pathway

Question 14

Which arachidonic acid metabolites are produced by the cyclooxygenase (COX) pathway?

Answer 14

Prostaglandins

Question 15

Which arachidonic acid metabolites are produced by the lipoxygenase pathway?

Answer 15

Leukotriens
Lipoxins

Question 16

(T/F) All arachidonic acid metabolites are pro-inflammatory mediators

Answer 16

FALSE. Prostaglandins and leukotriens are pro-inflammatory mediators however lipoxins are anti-inflammatory mediators

Question 17

What are the six main roles of prostaglandins and leukotriens in acute inflammation?

Answer 17

Vasodilation
Vasoconstriction
Increased vascular permeability
Chemotaxis
Pain inducement
Fever inducement

Question 18

What is the main role of lipoxins as an anti-inflammatory mediator?

Answer 18

Inhibition of leukocyte recruitment

Question 19

What can be used to inhibit the phospholipase enzymes?

Answer 19

Steroids

Question 20

What can be used to inhibit the cyclooxygenase (COX) pathway?

Answer 20

NSAIDS

Question 21

Which main cell type produces cytokines?

Answer 21

Macrophages

Question 22

What are the three possible stimuli for cytokine release?

Answer 22

Microbial products
Antigen-antibody complexes
Foreign bodies

Question 23

What are the two main roles of cytokines in acute inflammation?

Answer 23

Endothelial cell activation
Leukocyte activation

Question 24

What is the specific function of the IL-6 cytokine?

Answer 24

IL-6 stimulates local and systemic inflammation

Question 25

What is the specific function of the IL-17 cytokine?

Answer 25

IL-17 stimulates neutrophil recruitment

Question 26

What are the functions of TGF-β and IL-1 in chronic inflammation?

Answer 26

TGF-β and IL-1 terminate the immune response and stimulate fibrosis and tissue repair

Question 27

List two cytokine inhibitors

Answer 27

TNF-antagonists Steroids

Question 28

What are the four major groups of chemokines?

Answer 28

C CC CXC CX3C

Question 29

What are the two main roles of chemokines in acute inflammation?

Answer 29

Leukocyte attachment via integrins Leukocyte migration

Question 30

Which cell type is associated with the C group of chemokines?

Answer 30

Lymphocytes

Question 31

Which four cell types are associated with the CC group of chemokines?

Answer 31

Monocytes Basophils Eosinophils Lymphocytes

Question 32

Which cell type is associated with the CXC group of chemokines?

Answer 32

Neutrophils

Question 33

What are the two complement proteins collectively known as anaphylatoxins?

Answer 33

C3a and C5a are collectively known as anaphylatoxins

Question 34

Which complement protein promotes phagocytosis?

Answer 34

C3b promotes phagocytosis

Question 35

Which complement proteins promote cell lysis?

Answer 35

MAC complex (C5 - 9)