Chemical mediators Flashcards
Where does chemical mediators originate?
plasma or
cells
What does chemical mediators have?
triggering stimuli that target specific targets
What can chemical mediators cause?
cascade
mediators are short lived
What are the chemical mediators?
Histamine Serotonin Complement Kinins Clotting Factors Eicosanoids Nitric OxidePlatelet Activating Factor (PAF) Cytokines Chemokines Lysosome Constituents Free Radicals
Where does clotting factors originate?
circulating plasma
What are the function of clotting factors?
Coagulation, i.e., production
of fibrin- the purpose (Scab)
fibrinolysis- getting rid of the scab
Which cells does histamine mediate?
mast cells (inside blood vessel) basophils (outside blood vessel)
What is the function of mast/basopils/histamine?
powerful vasodilator
IgE on mast cell
Which cells produce Serotonin?
platlets
enterochromaffin cells
ser
What is the function of serotonin?
indirect vasodilation by evoking nitric oxide synthase
What is the action of the kinin system?
Increase permeability
Smooth muscle contraction, NON vascular (increases permeability)
PAIN (bradykinnin)- remember
What is a key component of the kinin system?
bradykinin for pain
What are the eicosanoids a part of?
plasma membrane
What are the function of protagladins (including thromboxane)?
Pain
Fever
Clotting
What is the function of leukotrienes?
Chemotaxis
Vasoconstriction
Increased permeability
What is the function of lipoxins?
INHIBIT chemotaxis
Vasodilatation
Counteract actions of leukotrienes
What is the function of PAF?
activate platelets
Vasoconstrict/brococonstrict [concentration dependent] cause smooth muscle contraction- At low levels of PAF they vasodialate and broncho dilate at high levels
What are PAF derived from?
Phospholipid-derived
What are cytokines?
PROTEINS produced by MANY cells, but usually LYMPHOCYTES AND MACROPHAGES,
What is the function of cytokines?
mediate and regulate inflammatory and immune reactions
What are cytokines that macrophages produce?
TNFα, IL-1
What are chemokines?
small proteins which are attractants for PMNs
What is the function of Nitric Oxide?
Potent Vasodilator
Involved in microbial killing (ONOO-)
Produced from the action of nitric oxide synthase from arginine
What are the lysosomal constituents?
primary immature neutrophils
secondary mature neutrophils
What are primary neutrophils also called?
AZUROPHILIC, or NON-SPECIFIC
What are secondary neutrophils called?
SPECIFIC
What does primary neutrophils produce?
Myeloperoxidase
Lysozyme (bact.)
Acid Hydrolases
What does secondary neutrophils produce?
lactoferrin
lysozyme
alkaline phosphate
collagenase
What free radicals that are produced?
O2− (SUPEROXIDE)
H2O2 (PEROXIDE)
•HO (HYDROXYL RADICAL)
VERY VERY DESTRUCTIVE
