Data in the literature supports the hypothesis that reactive oxygen species generated in the vascular wall alter vascular regulation. At present the majority of the literature tends to suggest that oxidant induced damage on the smooth muscle cell impair vasoconstriction. However, direct action of oxidants on the smooth muscle cell impair vasoconstrictor function. Differences in studies in the literature are likely to be reconciled when the target sites of reactive oxygen species are considered. Future research in this area should lead to a more comprehensive understanding on the impact of these pathways on vasoregulation in postischemic tissue.