Cytokines are soluble glycoproteins or small peptides released by living cells such as parenchyma, endothelium and leucocytes. Cytokines having an effect on inflammation may be conveniently subdivided into pro and anti inflammatory.
Inflammatory mediators are larger molecules than cytokines, they are proinflammatory and include platelet activated factor (PAF), leukotriene B4 (LTB4), C5 and thrombin.