There is increasing evidence that endogenous nitric oxide (NO) plays a key role in
physiological regulation of airway functions and is implicated in airway disease (Barnes and
Liew, 1995; Barnes, 1995). As elsewhere, NO derived from constitutive NO synthases
(cNOS) is involved in physiological regulation of airway function, whereas NO derived from
inducible NO synthase (iNOS) is involved in inflammatory diseases of the airways and in
host defence against infection. Greater understanding of the role of endogenous NO will …