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Tytuł:
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Intracellular Ca2+ transients in delta-sarcoglycan knockout mouse skeletal muscle.
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Autorzy:
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Solares-Pérez A; Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría, CMN Siglo XXI-IMSS, México, D.F., Mexico.
Sánchez JA
Zentella-Dehesa A
García MC
Coral-Vázquez RM
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Źródło:
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Biochimica et biophysica acta [Biochim Biophys Acta] 2010 Mar; Vol. 1800 (3), pp. 373-9. Date of Electronic Publication: 2009 Nov 18.
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Typ publikacji:
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Journal Article; Research Support, Non-U.S. Gov't
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Język:
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English
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Imprint Name(s):
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Original Publication: Amsterdam : Elsevier Pub. Co.
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MeSH Terms:
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Calcium/*physiology
Muscle Fibers, Skeletal/*physiology
Muscle, Skeletal/*metabolism
Sarcoglycans/*deficiency
Animals ; Electric Stimulation ; Hindlimb ; Humans ; Mice ; Mice, Inbred Strains ; Mice, Knockout ; Muscular Dystrophy, Animal/genetics ; Reference Values ; Signal Transduction/physiology
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Substance Nomenclature:
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0 (Sarcoglycans)
SY7Q814VUP (Calcium)
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Entry Date(s):
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Date Created: 20091126 Date Completed: 20100503 Latest Revision: 20161126
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Update Code:
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20240104
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DOI:
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10.1016/j.bbagen.2009.11.011
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PMID:
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19931597
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Background: delta-Sarcoglycan (delta-SG) knockout (KO) mice develop skeletal muscle histopathological alterations similar to those in humans with limb muscular dystrophy. Membrane fragility and increased Ca(2+) permeability have been linked to muscle degeneration. However, little is known about the mechanisms by which genetic defects lead to disease.
Methods: Isolated skeletal muscle fibers of wild-type and delta-SG KO mice were used to investigate whether the absence of delta-SG alters the increase in intracellular Ca(2+) during single twitches and tetani or during repeated stimulation. Immunolabeling, electrical field stimulation and Ca(2+) transient recording techniques with fluorescent indicators were used.
Results: Ca(2+) transients during single twitches and tetani generated by muscle fibers of delta-SG KO mice are similar to those of wild-type mice, but their amplitude is greatly decreased during protracted stimulation in KO compared to wild-type fibers. This impairment is independent of extracellular Ca(2+) and is mimicked in wild-type fibers by blocking store-operated calcium channels with 2-aminoethoxydiphenyl borate (2-APB). Also, immunolabeling indicates the localization of a delta-SG isoform in the sarcoplasmic reticulum of the isolated skeletal muscle fibers of wild-type animals, which may be related to the functional differences between wild-type and KO muscles.
Conclusions: delta-SG has a role in calcium homeostasis in skeletal muscle fibers.
General Significance: These results support a possible role of delta-SG on calcium homeostasis. The alterations caused by the absence of delta-SG may be related to the pathogenesis of muscular dystrophy.
(Copyright (c) 2009 Elsevier B.V. All rights reserved.)