2.5 Chemical Mediators of inflammation Flashcards Preview

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Flashcards in 2.5 Chemical Mediators of inflammation Deck (152)
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1

chemical mediators of inflammation

peptides,
lipids,
amines
- preformed or newly synthesized

2

where are these mediators found

in plasma
or cells

3

inflammatory mediators work by

binding receptors and many stimulate the release of other medeators

4

times life of inflammatory mediators

short lived
eg arachadonic acid

5

harmful to body

potentially - don't have inflammation until you make the mediators so you only have it where you want it but some like IL1 and TNF float around causing systemic effects

6

vasoactive amines

small molecular weight amines

7

vasoactive amines are found in

mast cells and platelets

8

vasoactive amines: preformed or synthesized

preformed and sequestered in cellular granules (active, not zymogens) ex histamine

9

Histamine found mostly in

mast cells

10

histamine is released by

physical injury,
IgE,
C3a and C5a,
cytokines (IL1 IL8)

11

fn of histamine

constricts large arteries,
vasodialation (small art)
and increased vascular permeability (venous)

12

histamine causes

itching pain

13

histamine works by

binding to H1 receptors

14

serotonin is found in

platelets but NOT mast cells

15

serotonin actions

same as histamine

16

role in inflammatory response of serotonin

in rats it is found in mast cells but we don't know its role in human inflammation. Mostly described in the CNS

17

complemet

proteases found in plasma that are preformed as zymogens

18

complement activation (cascade) paths

classical,
alternative,
lectin

19

classical complement

ag-aby complex-->C1qrs complex
that cleaves C2 and C4 liberating C4a and
froming C3 convertase,

C3 convertase cleaves C3 liberating C2a and C3 b,

C3b associates with C3 convertase and activates C5 liberating C5a,

activated C56789 forms the MAC

20

C3a C4a and C5a are

chemotactic, but mostly C5a

21

C3b is an

opsonin

22

alternative path

microbial surfaces --> C3 --> C3a and C3b,
C3b --> C5 --> C5a + C5b(-->MAC)

23

Lectin path

plasma lectin binds to microbe C2, C4 act - C3a and 5a are liberated _slide 99

24

C3a and C5a are

anaphylatoxins --> C4a too a little

25

C5b and C6, 7, 8, 9

MAC complex

26

C3a

histamine release from mast cells (vasodialation and inc. vascular permeability indirectly)

27

C5a

histamine release from mast cell,
AA metabolism,
leukocyte chemotaxis,
adhesion,
activation

28

Plasmogen activator --> plasminogen --> plasmin

plasmin truns fibrin into split products, and
cleaves C3 and C5 to relieve C3a and C5a

29

central and commited step of complement

formation fo C3a and C3b - this step is the focus of regulatin

30

DAF

decay accelerating factor
enhances disassociation of C3 convertase
(to inhibit further activation of complement)