Cell Derived Mediators of Inflammation Flashcards
What are types of cell-derived mediators of inflammation?
Vasoactive amines
Arachidonic acid metabolites
Nitric oxide
Platelet activating factor
Cytokines
What cells produce histamine?
Basophils and mast cells
What is the function of histamine?
Increased vascular permeability and increased vasodilation
What is the function of serotonin as an inflammatory mediator?
Platelet activation
What are two cell-derived vasoactive amines that mediate inflammation?
Histamine and serotonin
What is the most important “superstar” cell-derived mediator of inflammation?
Histamine
Where are the highest levels of serotonin located in the body?
Gut
Where is arachidonic acid located?
Cell membrane
What enzyme releases arachidonic acid from the cell membrane?
Phospholipase
What plasma derived mediator of inflammation produced from the complement system assists in arachidonic acid metabolism?
C5a
What enzyme converts arachidonic acid into leukotrienes and lipoxins?
Lipoxygenase (LOX)
What are examples of leukotrienes?
LTB4
LTC4
LTD4
LTE4
What is the function of LTB4?
- chemotactic agent for phagocytic cells
- stimulates phagocytic cell adherence
- increases vascular permeability
What is the difference between C5a and LTB4 as chemotactic agents?
C5a is a plasma derived chemotactic agent in the complement system while LTB4 is a cell derived chemotactic agent for phagocytes in the LOX pathway
What is the function of LTC4, LTD4, and LTE4?
- Bronchoconstriction (smooth muscle contraction)
- increased vasodilation and vascular permeability
What leukotrienes are present in asthmatic and type I hypersensitivity reactions?
LTB4, LTC4, LTD4, and LTE4
What drug can inhibit the lipoxygenase enzyme and the conversion of arachidonic acid to leukotrienes?
Singulair (or other anti-asthmatics)