Inflammation and Repair Part 2 Flashcards
What are the 2 major sources of chemical mediators?
Cells (produced locally)
plasma (Produced elsewhere)
What are the 2 types of chemical mediators that are produced by cells?
Preformed (vasoactive amines) Newly synthesized (Prostaglandins and cytokines)
What are the chemical mediators within plasma (3)?
Complement, kinins and coagulation system
Where are many of the plasma chemical mediator produced? Where are they activated?
Many produced in the liver
Activated at the site of injury
What is the major preformed vasoactive amine? What cells secrete it? Where is it found?
Histamine
Secreted by mast cells
Found in most tissues
What are the 3 major functions of histamine?
- Causes vasodilatation of arterioles
- increased venule permeability
- Prominent in allergic response, edema
What is a vasoactive amine found in platelets? What is its major function?
Serotonin
Induces vasoconstriction during clotting
Arachidonic acid is considered a cell derived mediator. Where is it found in the cell? What activates it?
Found in the cell membrane
Activated by phospholipases
Regarding the arachidonic acid metabolites pathway, which enzyme is inhibited by steroids? Which is inhibited by NSAIDs?
Phospholipases inhibited by steroids
Cycloxygenase inhibited by NSAIDs
Regarding the cyclooxygenase pathway, what are the 2 major bioactive downstream products? What are their functions?
- Prostacyclin - vasodilation, platelet inhibition
- Thromboxane - Vasoconstriction, platelet activation
What are the 2 major bioactive products of the lipoxygenase component of the arachidonic acid pathway? What are their functions?
Leukotrienes - Bronchospasm and increased vascular permeability
Lipoxins - Inhibit neutrophil adhesions and chemotaxis
What are the 4 mediators that are important for vasodilation?
PGI2, PGE1, PGE2 and PGD
What ae the 4 mediators that are important for vasoconstriction?
TXA2, Leukotrienes C4, D4 and E4
What are the cell derived mediators that increase vascular permeability?
Leukotrienes C4, D4 and E4
What are the cell derived mediators that promote chemotaxis and leukocyte adhesion?
Leukotriene B4 and HETE
What are the 4 major cytokines that are important for acute inflammation?
TNF
IL-1
IL-6
Chemokines
What are the 2 cytokines that are important for chronic inflammation?
Interferon gamma
IL-12
TNF and IL1 are produced by what 3 types of cells?
Activated macrophages
Endothelial cells
Mast cells
What is the major role of TNF and IL1?
Endothelial activation leading to increased permeability and expression of adhesion molecules
What are the 2 major functions of nitric oxide?
Vasodilation
Macrophage cytotoxicity
What are the sources of nitric oxide (2)?
Endothelial cells (chronic low levels) Macrophages (inducible, plays a role in killing of microorganisms)
What are the 2 antiinflammatory roles of nitric oxide?
Reduces leukocyte activity
Reduces platelet adhesion