It is increasingly apparent that oxidants can play an important role in mediating specific cell responses and expression of genes involved in degenerative pathophysiologic states, such as inflammation. In particular, oxidant-induced activation of the multisubunit nuclear transcription factor, NFkappaB, has been implicated in the transcriptional upregulation of inflammatory genes like endothelial cell adhesion glycoproteins. A second emerging concept is the recognition that the oxidant effects in cellular and molecular regulation may be mediated by oxidant-induced loss of cellular oxidation-reduction (redox) balance. This review will provide an overview of our current understanding of leukocyte-endothelial cell interactions derived from in vitro studies of endothelial cell monolayers exposed to anoxia/reoxygenation, with specific emphasis on the molecular determinants mediating this inflammatory process and the contribution of reoxygenation-induced cellular redox imbalance to the activation of NFkappaB and the expression of endothelial surface adhesion molecules.