Path: Chemical Mediators of Inflammation

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histamine: most imp mediator

synthesized by basophils/ mast cells

vasodilator/ inc. vessel perm, important in anaphylactic shock, causes wheal and flare
serotonin: released/ syn by basophils/mast cells/ platelets

synthesized from tryptophan

important in carcinoid syndrome
what is the fxn of serotonin?: vasodilator/ inc. vessel permeability

neurotransmitter
what are the fxns of C3a/C5a?: anaphylotoxins

directly stimulate histamine release from basophils/ mast cells

important in tissue swelling and shock
what is the fxn of C3b?: opsinizing agent

neutrophils/monocytes/ macrophages have receptors
what does C5a do?: anaphylotoxin and chemotactic agent

activates cascade that lead to LOX pathway

adhesion molecule synthesis on neutrophils
what does bradykinin do?: stimulates vasodilation, inc. vessel permeability, and causes pain

also a bronchoconstrictor

cough and angioedema with ACE inhibitors
Tell me what you know about prostoglandins in general: derived from arachadonic acid (called eiconisoids)

released from phospholipids in cell membranes by activation of phospholipase A2

synthesized from linoleic acid

*most prostoglandins are vasodilators/ inc. vessel permeability
what is Thromboxane A2 (TXA2)?: PGH2 is converted by platelet-derived thromboxane synthase into TXA2

prodcut of arachadonic acid metabolism

TXB2 is the end product of its metabolism
What does TXA2 do?: vasoconstricts and stimulates platelet aggregation
How is prostacyclin (PGI2) made?: PGH2 is converted by endothelial cell dervied prostacylclin synthase into PGI2

*prostacyclin synthase is not inhibited to any significant degree by aspirin and NSAIDs
what does PGI2 do?: vasodilates

inhibits platelet aggregation
What does PGE2 do?: *makes skin hypersensitive to pain
*vasodilates in kidney(blocked by NSAIDS, but not by acetominophen)
*Inc. renal blood flow
*Dec. renal absorption of Na
*inc. gastric mucosa blood flow
*activates osteoclasts
*imp in fever production
*inhibits platelet aggregation/IL-1 and IL2/leukocyte aggregation
what does PGF2a do?: constricts uterine muscles

vasoconstricts/bronchoconstricts
what does PGD2?: vasodilates and increases vessel permeability
what does LTB4 do?: adhesion molecule synthesis on neutrophils

chemotactic agent for neutrophils

*derived from arachodonic acid
What do LTC-D-E4 do?: bronchoconstrict and vasoconstrict

important in asthma

* derived from AA
what does nitric oxide do?: vasodilator/ increases vessel permeability

inportant in shock

*endothelial cell derived
What is the main Ig of acute inflammattion?: IgM
What is endothelin? what does it do?: potent vaosconstrictor in endothelial cells

important in shock
What are the fxns of Hageman factor XII?: activates intrinsic coagulation system

activates plasminogin in fibrolytic system

actiavates kinin system--> bradykinin prodxn

*important in the pathogenesis of disseminated intravascular coagulation (DIC)
What is the main Ig in chronic inflammation?: IgG
What are the functions of IL-1?: *fever: stimulates PGE2 synthesis in anterior hypothalamus
*B Cell stimulation to synthesize Igs
*activates osteoclasts
*increases adhesion molecule synthesis by endothelial cells
*increases liver synthesis of acute phase reactants
what does interferon-y do?: activates macrophages to kill microbial pathogens

antiviral activity

induces MHC antigens

increases production of IL-2 and IL-12 by CD4-T helper cells

* produced by CD4 T helper cells
IL-2: source and fxn?: made by CD4 T helper cells

primarily a T cell growth factor

promotes B cell/ NK cell proliferation
IL-3: source and fxn?: T cells, thymic epithelial cells

stimulates proliferation of T cells, B cells, and NK cells

activates monocytes

increases hematopoiesis
IL-4: source and fxn?: activated T Cells

mainly promotes growth of B Cells

enhances expression of HLA class II antigens

switch of IgM synthesis in B cells to IgE syn in type I hypersensitivity rxns
IL-5: source and fxn?: T cells and mast cells

promotes end stage maturationof B cells into plasma cells

IgE synthesis, growth of eosinophils
IL-6: source and fxn?: T cells, monocytes/macrophages, others

promotes maturation of B and T cells

inhibits growth of fibroblasts

stimulates synthesis of acute phase reactants in liver in acute inflammation
IL-12: source and fxn?: macrophages

promotes growth of CD8 T cells

differentiation of CD4 T helper cells into Th1 and Th2 classes
- imp in granuloma formation
- imp in prodxn of memory T cells

promotes interferon-y production

enhances NK activity
Interferon-alpha (IFN-a): source and fxn?: B cells and macrophages

antivral activity
IFN-B: source and fxn?: Fibroblasts

antiviral activity
Tumor Necrosis Factor-a (cahectin): source and fxn?: macrophages, T cells, and NK cells

Stimulates T cell proliferation and IL-2 production, cytotoxic to some tumor cells
TNF-B:source and fxn?: T cells

Stimulates T cell
proliferation and IL-2 production, cytotoxic to some tumor cells
What vasoactive mediator mediates vasoconstriction?: TxA2

LTC4, LTD4, LTE4

PAF
What vasoactive mediator mediates vasodilation?: PGI2

PGD2, PGE2, PGF2a

Bradykinin

PAF
What vasoactive mediator mediates Increased vascular permeability?: Histamine
serotonin
PGD2, PGE2, PGF2a
LTC4, LTD4, LTE4
bradykinin
PAF
Nitric oxide

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Deck Info

Number of cards 37