Airway nitric oxide in Duchenne muscular dystrophy.

The expression of muscle membrane-associated neuronal nitric oxide synthase (NOS1) is significantly impaired in Duchenne muscular dystrophy. Mean (+/- SEM) exhaled NO in 13 male patients with Duchenne muscular dystrophy was significantly lower than in 11 healthy age-matched male control subjects (7.5 +/- 1.4 vs 16.6 +/- 3.2 parts per billion, P <.02) or 17 adult male control subjects (18.5 +/- 1.8 parts per billion, P <.001). These findings provide indirect evidence that NOS1 contributes significantly to fractional exhaled nitric oxide in healthy children.