Muscular Dystrophy in mdx Mice Despite Lack of Neuronal Nitric Oxide Synthase

• Published in: Journal of neurochemistry Vol. 71; no. 2; pp. 784 - 789
• Main Authors: Chao, Daniel S., Silvagno, Francesca, Bredt, David S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.08.1998; Blackwell
• Subjects: Animals; Biological and medical sciences; Cell Membrane Permeability - physiology; Diseases of striated muscles. Neuromuscular diseases; Duchenne muscular dystrophy; Female; Male; mdx mice; Medical sciences; Mice; Mice, Inbred mdx - physiology; Mice, Knockout - physiology; Muscle, Skeletal - enzymology; Muscle, Skeletal - pathology; Muscular Dystrophy, Animal - metabolism; Muscular Dystrophy, Animal - pathology; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurology; Neuronal nitric oxide synthase; Neurons - enzymology; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type I; Pedigree; Sarcolemma - enzymology; Sarcolemma; Animal model; Neuromuscular diseases; Nervous system diseases; Enzyme; Rodentia; Striated muscle; Cytosol; Protein; Nitric-oxide synthase; Genetic disease; Vertebrata; Mammalia; Histopathology; Mouse; Nitric oxide; Duchenne muscular dystrophy; Oxidoreductases; Localization; Dystrophin
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1046/j.1471-4159.1998.71020784.x

: Neuronal nitric oxide synthase (nNOS) is a component of the dystrophin complex in skeletal muscle. The absence of dystrophin protein in Duchenne muscular dystrophy and in mdx mouse causes a redistribution of nNOS from the plasma membrane to the cytosol in muscle cells. Aberrant nNOS activity in the cytosol can induce free radical oxidation, which is toxic to myofibers. To test the hypothesis that derangements in nNOS disposition mediate muscle damage in Duchenne dystrophy, we bred dystrophin‐deficient mdx male mice and female mdx heterozygote mice that lack nNOS. We found that genetic deletion of nNOS does not itself cause detectable pathology and that removal of nNOS does not influence the extent of increased sarcolemmal permeability in dystrophin‐deficient mice. Thus, histological analyses of nNOS‐dystrophin double mutants show pathological changes similar to the dystrophin mutation alone. Taken together, nNOS defects alone do not produce muscular dystrophy in the mdx model.