Chemical Mediators of Inflammation

Question 1

Chemical mediators of inflammation can be ________ or _______.

Answer 1

cell derived; plasma-protein derived

Question 2

Histamine functions by ________.

Answer 2

dilating arterioles and contracting endothelial cells

Question 3

Serotonin leads to _______.

Answer 3

vasoconstriction to aid in clotting (it is present in platelet granules)

Question 4

Arachidonic acid is derived from _________.

Answer 4

membrane lipids (cleaved by phospholipase)

Question 5

Arachidonic acid is catalyzed by __________, an enzyme inhibited by aspirin and other NSAIDs.

Answer 5

cyclooxygenase (leading to thromboxanes and prostaglandins) and lipoxygenase (resulting in leukotrienes and lipoxins)

Question 6

Glucocorticords inhibit the _______ of the prostaglandin pathway.

Answer 6

phospholipase that produces arachidonic acid

Question 7

______ stimulates the growth and function of T cells.

Answer 7

IL-12

Question 8

What is the first enzyme in the lipoxin/leukotriene pathway?

Answer 8

5-lipoxygenase

Question 9

Lipoxins ___________.

Answer 9

antagonize leukotrienes and act as anti-inflammatory molecules

Question 10

Leukotrienes serve as ____________.

Answer 10

chemotactic agents for neutrophils and inducers of vascular permeability

Question 11

Platelet-activating factor ____________.

Answer 11

is also derived from membranes (by phospholipases) that induces platelet aggregation, bronchoconstriction, vascular permeability, vasodilation

Question 12

IL-1 and TNF, released by macrophages in acute inflammation, stimulate ________.

Answer 12

endothelial activation, systemic effects of inflammation (fever), and T cell activation

Question 13

In addition to vasodilation, NO also antagonizes ______.

Answer 13

platelet activation

Question 14

The initiating factor in the complement cascade is ______.

Answer 14

C3 convertase activation (which cleaves C3 into C3a and C3b)

Question 15

Complement can be activated by ________.

Answer 15

1) classical (antigen-antibody complexes)
2) pathogen surfaces
3) mannose-binding lectin (lectin binds to microbial mannose)

Question 16

C3b binds to C3 convertase to become ______.

Answer 16

C5

Question 17

In the plasma protein mediator system, factor XII (the Hageman factor) activates the _____ system.

Answer 17

kinin (leads to increased vascular permeability)

Question 18

List some anti-inflammatory factors.

Answer 18

lipoxins, C1 inhibitors, IL-10, and TGF-beta

Question 19

Mast cells release histamine in response to __________.

Answer 19

IgE; mechanical or thermal trauma; neuropeptides; cytokines; IL-1 and IL-8

Question 20

The two important chronic-inflammation mediators are ______.

Answer 20

IL-12 and IFN-gamma

Question 21

NO functions in inflammation by _________.

Answer 21

acting as a free-radical, mediating vasodilation, antagonizing platelet aggregation, and reducing leukocyte recruitment

Question 22

Alpha-1-antitrypsin inhibits _______ and alpha-2-macroglobulin inhibits __________.

Answer 22

elastase released by neutrophils; many proteases, including collagenase

Question 23

Neuropeptides are particularly active in _______, and include ________, a polypeptide that stimulates inflammation in epithelial and immune cells.

Answer 23

the lungs and GI tract; Substance P

Question 24

C3b binds to ______ and initiates _____.

Answer 24

C3 convertase; conversion of C5 to C5b (which activates the MAC) and C5a, a chemotactic and anaphylatic signal

Question 25

Bradykinin leads to __________.

Answer 25

increased vascular permeability, dilation, and pain

Question 26

Factor XII activates the __________.

Answer 26

clotting cascade

Question 27

_____ down regulates macrophages.

Answer 27

IL-10