Inflammatory Mediators

Question 1

Histamine

Synthesis:

Degradation:

Biological Activities:

Receptors:

Answer 1

Histadine–> L-histadine decarboxylase–> histamine

?

Vasodilation (Redness, heat)
Increased vascular permiability –> edema
Airway constriction
Hypotension

H1
H2
H3
H4

Question 2

Histamine H1 receptor:

Answer 2

Bronchoconstriction

Contraction of GI smooth muscle

Increased capillary permeability

Pruritis and pain

Release of catecholamines from adrenal medulla

Question 3

Histamine H2 receptor:

Answer 3

Gastric acid secretion

Inhibition of IgE-mediated basophil histamine release

Inhibition of T-cell mediated cytotoxicity

Suppression of Th2’s and cytokines

Nasal mucous secretion

Question 4

Histamine H3 and H4 receptors:

Answer 4

present on histaminergic nerve terminals (H3) and many immune cells (H4; eosinophils, dendrites, T-cells, neutrophils)

Question 5

Mixed H1/2 histamine receptor response:

Answer 5

increased heart rate

increased force of cardiac contraction

increased arrhythmias

slows AV conduction (primarily H1)

Question 6

Redness–vasodilation

Answer 6

histamine

PGE2

PGI2

Kinins

Question 7

swelling

increased vascular permeability

Answer 7

histamine

peptido leukotrienes (LTC4, LTD4, LTE4)

Kinins

Question 8

Pain

Answer 8

PGE

PGI

LTB4

Kinins

Question 9

Chemotaxis

Answer 9

LTB4 (neutrophils)

Peptido Leukotrienes (eosinophils)

Question 10

Fever

Answer 10

PGEs

Question 11

Airway constriction

Answer 11

histamine

peptido leukotrienes

kinins

PGD2

Question 12

hypotension

Answer 12

kinins

histamine

Question 13

platelets aggregation

vasoconstriction

Answer 13

TXA2

Question 14

opposes platelet aggregation

vasodilation

Answer 14

PGI2

Question 15

chemotactic for PMNs

reduces pain threshold

Answer 15

LTB4

Question 16

VERY strong vasodilator –> hypotension

Answer 16

kinins

Question 17

Converts histidine to histamine

where is it located?

Answer 17

L-histidine decarboxylase

mast cells and basophils

Question 18

What is the “triple response”?

What causes it?

Answer 18

localized redness

flare

localized edema or wheal formation

**cause by histamine

Question 19

Phospholipids –> ___?_____ –> arachidonic acid

Answer 19

phospholipase A2

Question 20

Arachidonic acid–> ___?____ –> prostanoids (PG & TX)

Answer 20

cyclooxygenase COX 1/2

Question 21

Arachidonic acid –> ___?___ –> leukotrienes

Answer 21

lipoxygenase LOX

Question 22

Receptor for peptido leukotrienes causing:

BRONCHOCONSTRICTION

eosinophil chemotaxis and cytokine secretion

increased vascular permeability

increased mucous production

dendritic cell migration and maturation

smooth muscle proliferation

Answer 22

Cys LTR1

Question 23

Receptor for peptido leukotrienes causing:

endothelial cell migration and activation

fibrosis

Answer 23

Cys LTR2

Question 24

Cys LTR1 inhibitors?

Answer 24

Montelukast

Zafirlukast

Question 25

Enzyme converting AA to LTA4?

Answer 25

5-lipoxygenase

Question 26

Inhibitor of 5-lipoxygenase?

Answer 26

Zileuton

Question 27

Degrades bradykinin to prevent hypotension?

Answer 27

Angiotensin converting enzyme (ACE)

Question 28

How do kinins cause such severe hypotension?

Answer 28

vasodilation

Question 29

Which receptor do kinins interact with to cause vasodilation?

Answer 29

B2