Study Set Content:
is a potent chemotactic agent and activator of neutrophils, causing aggregation and adhesion of the cells to venular endothelium, generation of ROS and release of lysosomal enzymes
LTB4
The cysteinyl-containing leukotrienes
LTC4, LTD4, and LTE4
cause intense vasoconstriction, bronchospasm (important in asthma), and increased permeability of venules.
The cysteinyl-containing leukotrienes LTC4, LTD4, and LTE4
True or False:
Histamines are more potent than Leukotrienes in increasing vascular permeability and causing
bronchospasm.
False: Leukotrienes are more potent
also generated from AA by the lipoxygenase pathway
Lipoxins
suppresses inflammation by inhibiting neutrophil chemotaxis and adhesion to endothelium.
Lipoxins
synthesize precursors of active lipoxins and pass these to platelets, where they are converted to mature lipoxins
Neutrophils
include aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs), such as ibuprofen.
Cyclooxygenase inhibitors
5-Lipoxygenase is not affected by NSAIDs, and many new inhibitors of this enzyme pathway have been developed
lipoxygenase inhibitors
are broad-spectrum antinflammatory agents that reduce the transcription of genes encoding many proteins involved in inflammation, including COX-2, phospholipase A2, proinflammatory cytokines and INOS
Corticosteroids
block leukotriene receptors and prevent the actions of the leukotrienes.
Leukotriene receptor antagonists
proteins produced by many cell types dendritic cells that mediate
and regulate immune and inflammatory reactions
Cytokines
critical roles in leukocyte recruitment by promoting adhesion of leukocytes to endothelium and their migration through blood vessels
TNF and IL-1
produced mainly by activated macrophages and dendritic cells
TNF & IL-1
produced by T lymphocytes and mast cells
TNF
produced by some epithelial cells
IL-1
The secretion of TNF and IL-1 can be stimulated by:
- microbial products
- dead cells
- immune complexes
- foreign bodies
- physical injury
Both TNF and IL-1 act on endothelium to induce a spectrum of changes referred to as endothelial activation
Endothelial activation
TNF augments responses of neutrophils to other stimuli such as bacterial endotoxin and stimulates the microbicidal activity of macrophages
Activation of leukocytes and other cells
induce the systemic acute-phase responses associated with infection or injury
TNF & IL-1
