Mediators Of Acute Inflammation

Question 1

List the most important mediators of inflammation

Answer 1

1) Vasoactive amines (histamine and serotonin)
2) Lipid products ( prostaglandins and leukotrienes)
3) Cytokines including chemokines
4) products of complement system

Question 2

Mediators are either secreted by ________ or mediated by________

Answer 2

Cells or mediated by plasma proteins

Question 3

Histamine source and action

Answer 3

Source: mast cells, basophils, or platelets
Action: Vasodilation of arterioles, increased vascular permeability and endothelial activation

Question 4

Prostaglandins source and action

Answer 4

Source: mast cells, leukocytes
Action: vasodilation, fever and pain

Question 5

Leukotrienes source and action

Answer 5

Source: mast cells, leukocytes
Action: increased vascular permeability, chemokines, leukocytes adhesion and activation

Question 6

C-3a and C5b what do they do

Answer 6

Parts of the complement system that trigger release of mast cell granules hence histamine

Question 7

List other things that can trigger the release of histamine asides C3a and C5b

Answer 7

Substance p and cytokines like IL-1 and IL-8

Question 8

What mediates the vasoactive effect of histamine

Answer 8

HI receptors on microvascular endothelial cells

Question 9

Serotonin location and action

Answer 9

Location: platelets and some neuro endocrine cells like the GI tracts, also in mast cells of rodents but not humans
Action: Functions primarily as a neurotransmitter in the GI tract
A vasoconstrictor

Question 10

What type of receptors do arachidonic acid metabolites bind to

Answer 10

G- protein coupled receptors on many cell types and mediate virtually every step in inflammation

Question 11

Arachidonic acid metabolites that cause vasodilation

Answer 11

Prostaglandin I2, D2,E2 E1

Question 12

Arachidonic acid metabolites that cause vasoconstriction

Answer 12

Thromboxane A2, leukotrienes C4,D4, E4

Question 13

Arachidonic acid metabolites that cause increased vascular permeability

Answer 13

Leukotrienes C4, D4, E4

Question 14

Arachidonic acid metabolites that cause chemo taxis and leukocyte adhesion

Answer 14

Leukotrienes B4, HETE

Question 15

Prostaglandins are produced by

Answer 15

Mast cells, macrophages, endothelial cells and many other cell types

Question 16

TxA2 is a potent _____________

Answer 16

Platelet aggregating agent and vasoconstriction
It is unstable and rapidly converted to its inactive state Tx B2

Question 17

Prostacyclin is a potent __________

Answer 17

Inhibitor of platelet aggregation and a vasodilator

Question 18

A thromboxane prostacyclin imbalance is seen where

Answer 18

Thrombus formation in coronary and cerebral blood vessels

Question 19

What is the predominant lipoxygenase in neutrophils

Answer 19

5- lipoxygenase

Question 20

Functions of leukotrienes

Answer 20

Intense vasoconstriction, bronchospasm( asthma) and increased permeability of venules

Question 21

Lipoxins functions

Answer 21

Suppress inflammation by inhibiting recruitment of leukocytes
They inhibit neutrophil chemotaxis and adhesion to endothelium

Question 22

Cyclooxygenase inhibitors

Answer 22

Aspirin, NSAIDS like ibruprofen

Question 23

Cox 2 inhibitors may increase the risk of

Answer 23

Cardiovascular and cerebrovascular events

Question 24

Inhibitors of leukotrienes

Answer 24

Zileuton used for asthma treatment

Question 25

What are corticosteroids used for

Answer 25

Anti inflammatory agents that reduce transcription of genes encoding COx 2, phospholipids A2, pro inflammatory cytokines

Question 26

What is responsible for systemic acute phase response

Answer 26

IL-1, TNF, IL-6

Question 27

List systemic acute phase responses

Answer 27

Fever
Sepsis
Sustained production of TNG contributes to cachexia thay accompanies some chronic infections

Question 28

TNF antagonists are effective in treatment of

Answer 28

Chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, some inflammatory bowel disease

Question 29

Complications of TNF antagonist

Answer 29

Patients become more susceptible to mycobacteria’s infection

Question 30

Example of CXC chemokines

Answer 30

IL-8

Question 31

Example of C-C chemokines

Answer 31

MCP-1 ( monocyte chemoattractant proteins), MIP-1alpha ( macrophages inflammatory protein), Eotaxin, RANTES

Question 32

Example of C chemokines

Answer 32

Lymphotactin

Question 33

Chemokines can be classified into four major groups list

Answer 33

1) CXC chemokines e.g IL-8
2) C-C chemokines e.g MCP-1, MIP-1, eotaxin, RANTES
3) C chemokines lymphotactin
4) CX3C chemokines e.g fractalkine

Question 34

Example of CX3C chemokines

Answer 34

Fractalkine

Question 35

Functions of chemokines in acute inflammation

Answer 35

1) stimulates neutrophil attachment to the endothelium by increasing integrin affinity
2) stimulates chemotaxsis
3) maintenance of tissue architecture

Question 36

Functions of compliment system

Answer 36

1) inflammation
2) opsonisation and phagocytosis
3) Cell lysis