[Activated granulocytes as producers of reactive oxygen species--their significance for inflammatory reaction].

The release of reactive oxygen species (ROS) by activated granulocytes is essential for the destruction of microbes and parasites in humans. Therefore, granulocytes play an important role in the pathogenesis of inflammatory reactions, particularly in inflammatory skin diseases. Besides their well-known toxic effects, ROS are capable of modulating a variety of different immune functions. The present review, therefore, focuses on the biological effects of ROS, on other producer cells of ROS besides granulocytes, on biochemical aspects of the production and interactions of ROS and on methods of detecting ROS production. Apart from well-known stimuli, which may be devoid of any physiological relevance or only induce a short-lived activation of granulocytes, cytokines are reported to induce a release of ROS. A possible modulatory effect of cytokines derived from immunocompetent and other cells on granulocyte activity could be of major importance for our understanding of the cellular interactions during inflammatory reactions, particularly in diseases characterized by granulocyte activation. The data presented allow a better understanding of the complex regulatory process of granulocyte activation in inflammatory skin diseases.