THE EVOLUTION OF INFLAMMATORY MEDIATORS

Invertebrates do not display the level of sophistication in immune rea ctivity characteristic of mammals and other 'higher' vertebrates. Thei r great number and diversity of forms, however, reflect their evolutio nary success and hence they must have effective mechanisms of defence to deal with parasites and pathogens and altered self tissues. Inflamm ation appears to be an important first line defence in all invertebrat es and vertebrates. This brief review deals with the inflammatory resp onses of invertebrates and fish concentrating on the cell types involv ed and the mediators of inflammation, in particular, eicosanoids, cyto kines and adhesion molecules.