| Factors | Source | Effect |
|---|
| Arachidonic acid metabolites (prostagland ins and leukotrienes) | Phospholipids of cell membranes, especially mast cells | Primary mediators of late-stage (>6 hr) inflammation; increase dilation and permeability of blood vessels; stimulate neutrophil adhesion to endothelial tissue; bronchoconstriction; anaphylaxis |
| Bradykinin | Kinin system of plasma proteins | Primary mediator of prolonged (>1 hr) inflammation; vasodilation and increased permeability of blood vessels; pain; release of leukotrienes and prostagland ins |
| Complement proteins | Macrophages; liver endothelium | Increase vasodilation and vascular permeability; coat antigens to enhance phagocytosis; attract neutrophils; destroy pathogens |
| Histamine and serotonin | Mast cells; basophils | Primary mediators of early (≤30 min) inflammation; rapid dilation and increase in permeability of venules; bronchoconstriction; stimulation of prostagland in production |
| Interleukin 1 (IL-1) | Macrophages; B cells, dendritic cells, neutrophils, other nucleated cells | Increased production and activity of other chemical mediators, phagocytes and lymphocytes; promotes release of acute-phase proteins; causes fever |
| Interleukin 8 (IL-8) | T lymphocytes; monocytes | Attracts neutrophils and more T cells |
| Platelet-activating factor (PAF) | Platelets | Releases chemical mediators; activates neutrophils; dilates and increases permeability of vessels |
| Transforming growth factor β (TFGβ) | Activated macrophages and T lymphocytes | Attracts neutrophils and monocytes; stimulates growth of connective tissue; inhibits other mediators |
| Tumor necrosis factors (TFNα) | Activated macrophages and some lymphocytes | Increase synthesis of other cytokines; induce formation of new blood vessels; increase adhesion of neutrophils to endothelium; cause fever and cachexia |