inflammatory mediators Flashcards
what is the purpose of inflammation
to destroy, dilute the injurious agent and the consequences of an injury to heal the damaged tissue
what are the vascular events of acute inflammation
- dilation: increase hydrostatic pressure for inflow
what are cellular events in acute inflammation
leukocyte extravasation and phagocytosis
what are the endogenous/exogenous mediators of inflammation
exogenous: endotoxins
endogenous: plasma, leukocytes, endothelial cells, fibroblasts
actions of chemical mediators
vasodilation, increased vascular permeability, chemotaxic leukocyte activation, fever, pain, tissue damage and microbe killing
what causes vasodilation
prostaglandins, NO
what causes increased vascular permeability
histamine, serotonin, C3a C5a, bradykinin, leukotriens, PAF
what causes fever
IL1, IL6, TNF, prostaglandins
pain is caused by
prostaglandins, bradykinin
discuss the vasoactive amines released during inflammation
- histamine: from mast cells, basophils, platelets. Binds to H1 receptors on microvasculr endothelial cells. leads to dilated arterioles, and increased venous permeability
- serotonin: from platelets, rodent mast cells
arachidonic acid - eicosanioids are produced by
cyclo-oxygenase and lipooxigenase. they bind to GPCR.
lipoxins
neutrophils produce LTA4 which is converted to lipoxins by platelets. They inhibit leukocyte recruitment.
name 2 anti-inflammatory drugs
COX inhibitors, and COX2 selective inhibitors
- lipoxygenase inhibitors
- corticosteroids
effect of low dose aspirin
is an anti-thrombotic. platelets roduce TXA2. endothelium produces PGI2. mature platelets only express COX1.
- at low dosage aspirin blocks production of TXA2.
aspirin promotes
lipoxin production.
