Methods of detection of vascular reactive species: nitric oxide, superoxide, hydrogen peroxide, and peroxynitrite.

The evanescent nature of reactive oxygen and nitrogen species, the multiple cellular mechanisms evolved to maintain these substances at low (submicromolar) concentrations within the vascular system, and the often multifaceted nature of their reactivities have made measurement of these compounds within the vasculature problematic. This review attempts to provide a critical description of some of the most common approaches to quantification of nitric oxide, superoxide, hydrogen peroxide, and peroxynitrite, with attention to key issues that may influence the utility of a particular assay when adapted for use in vascular cells and tissues.