Is there a role for free radicals in the systemic inflammatory reaction?

This communication provides an insight that there is a differential response to stress by blood, which may directly reflect upon the induction of a proinflammatory state, with the goal of defining the sequence of oxido-inflammatory events that occur during extracorporeal circulation (ECC). In particular, we discussed if oxidative stress per se is one of the earliest pathophysiological events that occurs in ECC even before the inflammatory process sets in. The mechanism might involve the early activation of neutrophils, the most likely source of free radicals during the initial stages of ECC. However, the early increase in the oxidative stress (formation of 3-nitrotyrosine and lipid peroxidation) even before the initiation of ECC at a time when neutrophils are not yet to be activated, may suggest the existence of other factors responsible for the early oxidative stress.