C5a
Last reviewed 01/2018
Complement component C5a has the following functions:
- anaphylatoxin, promoting histamine release from mast cells and basophils, so increasing vascular permeability
- increases the surface expression of leukocyte adhesion molecules on endothelium, so promoting leukocyte transit into the extracellular space
- chemotactic agent for inflammatory leukocytes
- promotes killing action of leukocytes
- activates the lipoxygenase pathway of arachidonic acid metabolism in neutrophils and macrophages
C5a may be produced by the classical or alternative pathways, or, it may be a product of:
- trypsin
- bacterial proteases
- lysosomal enzymes released from a variety of leukocytes