ISSN:
1432-0533
Keywords:
Key wordsα1-syntrophin
;
Neuronal nitric oxide
;
synthase
;
Dystrophin
;
Ultrastructural localization
;
Skeletal muscle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We investigated the ultrastructural localization of α1-syntrophin and neuronal nitric oxide synthase (nNOS) in normal human skeletal myofibers and analyzed their relation to each other and to dystrophin using single and double immunogold-labeling electron microscopy. Single immunolabeling showed antibodies to α1-syntrophin and nNOS on the inner surface of the muscle plasma membrane, the sarcoplasmic side of plasma membrane invaginations, and the sarcoplasm near mitochondria of subsarcolemmal areas. The epitopes of α1-syntrophin and nNOS tended to be present in clusters. Double immunolabeling revealed that epitope combinations of α1-syntrophin-dystrophin, α1-syntrophin-nNOS, and nNOS-dystrophin occurred more frequently in doublet form than did other epitope combinations, such as α1-syntrophin-β-spectrin and nNOS-β-spectrin. These increased frequencies were noted both at the muscle plasma membrane undercoat and near mitochondria of subsarcolemmal areas. A significantly higher percentage of doublets comprised antibodies against α1-syntrophin and dystrophin (28.5 ± 1.5%, group mean ± SE) than those against α1-syntrophin and β-spectrin (9.2 ± 0.8%, P 〈 0.01). Furthermore, nNOS formed doublets significantly more frequently with dystrophin (25.2 ± 3.3%) and α1-syntrophin (26.0 ± 4.1%) than with β-spectrin (13.9 ± 2.3%; P 〈 0.05). These data support the association of dystrophin, α1-syntrophin, and nNOS at the inner surface of the muscle plasma membrane and near mitochondria of subsarcolemmal areas of normal human skeletal myofibers.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004010050733
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