The "new" chemical mediators of inflammation.

Significant progress has been made in the elucidation of the chemistry and biology of the products of arachidonic acid metabolism and the acetylated alkyl phosphoglycerides. While many of their biological properties make them tempting candidates as mediators of inflammation, their precise role in the acute and/or chronic inflammatory process remains to be proven. Thus, at present, it might be best to view these potent lipids not as inflammatory mediators but as autacoids. In the words of Douglas (16): "The very fact that the substances have been classified under the noncommital title of autacoids, is, in a sense, a confession that the evidence does not at present permit a more precise functional classification such as, for example, hormone or neurohormone.... But the core of the matter is that, while the autacoids possess an astonishingly wide range of pharmacologic activities and in vanishing small amounts, there are comparatively few instances where a physiologic role can be stated with assurance." Hopefully, the coming years should prove to be exciting and fruitful for students of inflammation and immunopathology; if so, we may be able to unequivocally elucidate the precise role(s) of these fascinating lipid autacoids in modulating the inflammatory process. At that time, the term autacoid may no longer be appropriate, and a new, functional classification, perhaps mediator, can be instituted with assurance.