Inflammatory Lung Injury Flashcards
what is one of the most potent inflammatory responses in the lungs?
immediate hypersensitivity reaction
pulmonary endothelial cells and epithelial cells are an important source of ____________________________________________
reactive nitrogen species
adhesion molecules
inflammatory mediators
how is histamine formed?
decarboxylation of histidine
when is histamine released in mast cells in pulmonary tissue?
when an allergen cross-links mast cell-bound IgE via high affinity receptors
what does histamine release lead to?
bronchial smooth muscle contraction
increased vascular permeability
mucosal edema
inflammatory cell infiltration
increased mucus in airways
epithelial loss
goblet cell hyperplasia
true/false: histamine sticks around for awhile
false: rapidly metabolized
how can histamine effects be prevented?
pharmacologic suppression of mast cell degranulation
competitive inhibition of histamine binding to receptors
how can histamine effects be counteracted?
bronchodilators
suppression of inflammatory cell recruitment
what does perturbation of inflammatory cell membranes cause?
release of arachidonic acid via activation of phospolipase A2
what metabolizes arachidonic acid? what does it make?
cyclooxygenase
results in prostaglandin or leukotriene formation
what generates PGF2alpha and what does it lead to?
cyclooxygenase metabolism
bronchoconstriction
what are the effects of arachidonic acid metabolites?
bronchoconstriction
vasodilation and local edema
increased mucus secretion
recruitment of additional inflammatory cells
how can arachidonic acid metabolism be inhibited?
corticosteroids
nonsteroidal anti-inflammatories inhibit cyclooxygenase
combination COX-LOX inhibiting drugs
what is platelet activation factor? what releases it?
a phospholipid released from membranes of leukocytes, macrophages, mast cells, platelets, and vascular endothelial cells
what does platelet activation factor do?
attracts/activates eosinophils, initiates platelet aggregation, and endothelial cell injury with consequent edema
why do phagocytic cells produce oxygen-derived free radicals?
they are essential to host phagocyte microbicidal activity
what can oxygen-derived free radicals damage?
proteins
nucleic acids
membrane lipids
extracellular matrix
what are interleukins, tumor necrosis factor, and macrophage inflammatory protein 1a released in response to?
endotoxin
immune complex phagocytosis
immune stimulation
toxins
physical injury
what does IL-8 do?
potent chemokine
neutrophils and PMN into pulmonary tissue
what does vasoactive intestinal peptide do and what releases it?
bronchodilator and mucus secretion
nerves and ganglia supplying lungs
what do substance P and tachykinins do and what releases them?
bronchoconstrictors and mucus secretion
sensory nerves
what mediates Type I hypersensitivity?
IgE bound to mast cells
what type of hypersensitivity mediates hypersensitivity pneumonitis?
type III: immune complex (arthus) reaction
what characterizes equine inflammatory airways disease and recurrent airway obstruction?
bronchoconstriction
neutrophil infiltration
excessive mucus production
Type I hypersensitivity
what mediates bovine hypersensitivity pneumonitis, allergic alveolitis?
IgG at level of pulmonary parenchyma
Type III hypersensitivity
how is histamine stored?
granules complexed with heparin
what is released when an allergen cross-links mast cell-bound IgE via high affinity receptors (Fc-epsilon-RI?
histamine
heparin
proteases
proteoglycans
