Immunolocalisation of neuronal nitric oxide synthase at the neuromuscular junction of MDX mice: a confocal microscopy study.
The distribution of nitric oxide synthase at the neuromuscular junction (NMJ) of normal, denervated and mdx mice was studied using a specific antibody against the neuronal isoform of nitric oxide synthase (nNOS). Fluorescence confocal microscopy demonstrated that nNOS immunoreactivity was localised mainly in the sarcolemma and presynaptic region covering acetylcholine receptor branches. The expression of presynaptic nNOS was greatly reduced in dystrophin-deficient muscles. In normal denervated muscles, nNOS was still present in the presynaptic region and there were no qualitative changes in the expression of this protein. These results suggest that the presynaptic distribution of nNOS is associated with terminal Schwann cells. The relationship between nNOS and the presynaptic components of the neuromuscular junction may open new perspectives for improving our understanding of the pathogenesis of dystrophic muscles.
Pereira
E C
EC
Department of Anatomy, Institute of Biology, State University of Campinas, Brazil.
Neto
H S
HS
Marques
M J
MJ
D000818:Animals; D051379:Mice; D018101:Mice, Inbred mdx; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D020388:Muscular Dystrophy, Duchenne / Q000201:enzymology*; D009469:Neuromuscular Junction / Q000201:enzymology* / Q000648:ultrastructure; D019001:Nitric Oxide Synthase / Q000032:analysis*; D052248:Nitric Oxide Synthase Type I; D017729:Presynaptic Terminals / Q000201:enzymology; D012508:Sarcolemma / Q000201:enzymology; D012583:Schwann Cells / Q000648:ultrastructure
D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse