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
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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
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vasoactive amines
small molecular weight amines
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vasoactive amines are found in
mast cells and platelets
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vasoactive amines: preformed or synthesized
preformed and sequestered in cellular granules (active, not zymogens) ex histamine
9
Histamine found mostly in
mast cells
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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
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histamine works by
binding to H1 receptors
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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
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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
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C3b is an
opsonin
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alternative path
microbial surfaces --> C3 --> C3a and C3b,
C3b --> C5 --> C5a + C5b(-->MAC)
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Lectin path
plasma lectin binds to microbe C2, C4 act - C3a and 5a are liberated _slide 99
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C3a and C5a are
anaphylatoxins --> C4a too a little
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C5b and C6, 7, 8, 9
MAC complex
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C3a
histamine release from mast cells (vasodialation and inc. vascular permeability indirectly)
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C5a
histamine release from mast cell,
AA metabolism,
leukocyte chemotaxis,
adhesion,
activation
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Plasmogen activator --> plasminogen --> plasmin
plasmin truns fibrin into split products, and
cleaves C3 and C5 to relieve C3a and C5a
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central and commited step of complement
formation fo C3a and C3b - this step is the focus of regulatin
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