Superoxide in the vascular system.

Oxidant production and regulation is becoming increasingly important in the study of vascular signaling mechanisms, and recent reviews have characterized some of the possible roles for known downstream products of superoxide formation. In this review, we will examine current research in the field, with a special emphasis on the role of the superoxide molecule itself and its place amongst the slightly better understood roles of peroxide and peroxynitrite. The regulatory roles of oxidant species are wide-ranging, and their involvement in processes ranging from intracellular and receptor signaling mechanisms that regulate endothelial mediator release and vascular contractile function to processes that control cellular growth and apoptosis has been implied. Cellular sources of superoxide production and metabolism and the chemical interaction of oxidant species with specific components of cellular signaling mechanisms are considered important factors which determine physiological responses that control vascular function. Copyright 2002 S. Karger AG, Basel