The measurement of nitric oxide production by cultured endothelial cells

Nitric oxide (NO) produced by vascular endothelial cells (ECs) plays a critical role in normal vascular physiology. Important insights into mechanisms regulating the production of endothelial NO have been derived from in vitro studies employing cultured ECs. Although many techniques for the detection of NO have been described, many of these methods lack adequate sensitivity to detect the small amount of NO produced by cultured ECs. In this chapter, we describe three protocols that employ chemiluminescence, electron spin resonance, or electrochemical techniques to permit the reliable detection of EC NO production.