Control and consequences of endothelial nitric oxide formation.

The intention of this chapter is to give a brief overview of the continuously expanding field of endothelium-derived NO. Over the past few years it has become apparent that the mechanisms controlling the activation of NOS are more complex than was previously thought, with factors such as pHi, [Ca2+]i, shear stress, and gender all contributing to the control of "basal" NO production as well as the regulation of NOS levels in endothelial cells. The list of the functional consequences of endothelial NO formation has also grown, with antiproliferative, antihypertensive, and antiatherogenic effects all being described. Recent advances at the molecular biology level have facilitated the pioneering of a whole new field of research, and a number of groups have shown that NO can modulate the expression of several genes, such as that encoding MCP-1, an effect that is probably due to an interaction between NO and transcription factors. Further elucidation of the signals that influence the production and actions of NO will, without doubt, further the understanding of numerous physiological and pathophysiological processes.