ABSTRACT
The discipline of nitric oxide biology is arguably among the most intensively studied, and intensively reviewed, in the biological sciences. Many recent reviews have covered the area of nitric oxide synthase (NOS) gene expression (1-5). In the interest of being timely, this chapter will focus on new developments in the area of transcriptional control over expression of the three NOS isoforms. It is recognized that post-transcriptional processes-e.g., alternate transcriptional start ing points, alternative splicing, and mRNA stability-can contribute greatly to the control of NO production. However, transcriptional regulation of gene ex pression is a novel and exciting aspect of control of the so-called “constitutively” expressed NOS isoforms and is the primary mode of regulation of the inducible isoform which is transcriptionally silent in most unstimulated tissues.
