Calcium regulation in muscle diseases; the influence of innervation and activity

Martonosi, Anthony

doi:10.1016/0304-4165(89)90110-4

Cited by 27 publications

(13 citation statements)

References 1,025 publications

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“…The resulting Ca2+ overload probably contributes to the Cu2+ toxicity. Sus tained increases of [Ca2+li can activate cytotoxic mecha nisms as Ca2+ -dependent proteases and Ca2+ -mediated phospholipases, which result in disruption of cytoskeletal organization, impairment of mitochondrial function and cessation of ATP synthesis in muscle [24].…”

Section: Discussionmentioning

confidence: 99%

Copper toxicity in cultured human skeletal muscle cells: the involvement of Na+/K+-ATPase and the Na+/Ca2+-exchanger

Benders

Lock

et al. 1994

Pflugers Arch.

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Section: Discussionmentioning

confidence: 99%

Copper toxicity in cultured human skeletal muscle cells: the involvement of Na+/K+-ATPase and the Na+/Ca2+-exchanger

Benders

Lock

et al. 1994

Pflugers Arch.

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“…It is well documented that dystrophic muscle cells present an increased content of total calcium (Martonosi, 1989), although contradictory results about cytosolic free calcium concentration have been reported (Turner et al, 1988;Gailly et al, 1993). The chronic calcium overload of skeletal muscle has been directly related to an enhancement of Ca2+-dependent proteolysis, that may lead to dystrophic cell necrosis (Turner et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

“…stasis, such as transport systems located in the surface membranes, sarcoplasmic reticulum (SR) or mitochondria. In dystrophic muscle, calcium sequestering mechanisms appear not to be modified (Martonosi, 1989;Turner et al, 1991) therefore, an alteration of calcium fluxes across the surface membranes of muscle fibres seems an attractive hypothesis.…”

Section: Introductionmentioning

confidence: 99%

“…Chicken muscular dystrophy, an inherited autosomal recessive disease, exhibits many of the clinical and laboratory signs of human dystrophies, including a reproducible progression in functional disability, degenerative changes in fast-twitch musde and abnormal elevations in plasma enzymes (Hudecki et al, 1984;Martonosi, 1989). Several laboratories have reported structural and molecular abnormalities in the affected muscles of dystrophic chicken: disarrangement of fibre structure with degeneration of contractile apparatus and alterations in the expression of myofibrillar protein isoforms; marked proliferation of T-tubular and junctional SR membranes accompanied by structural and biochemical defects, such as changes in the spatial relationship between T-tubules and SR, an over-expression of ryanodine receptor sites or a decrease in Mg2+-ATPase activity (Scales & Yasumura, 1982;Martonosi, 1989;Megias & Saborido, 1990;Pessah & Schiedt, 1990;Hayakawa et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

“…Several laboratories have reported structural and molecular abnormalities in the affected muscles of dystrophic chicken: disarrangement of fibre structure with degeneration of contractile apparatus and alterations in the expression of myofibrillar protein isoforms; marked proliferation of T-tubular and junctional SR membranes accompanied by structural and biochemical defects, such as changes in the spatial relationship between T-tubules and SR, an over-expression of ryanodine receptor sites or a decrease in Mg2+-ATPase activity (Scales & Yasumura, 1982;Martonosi, 1989;Megias & Saborido, 1990;Pessah & Schiedt, 1990;Hayakawa et al, 1993). Since dystrophic chicken muscle present a normal expression of dystrophin (Hoffman et al, 1988), the lacking protein in DMD muscle, the primary cause of the avian disorder must be different from that of DMD.…”

Section: Introductionmentioning

confidence: 99%

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Dihydropyridine receptors in transverse tubules from normal and dystrophic chicken skeletal muscle

Moro

Saborido

Delgado

et al. 1995

J Muscle Res Cell Motil

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Calcium overload is a fundamental pathogenic event associated with chronic muscle degeneration in muscular dystrophies. The possibility that L-type voltage-dependent calcium channels were involved in the etiology of chicken muscular dystrophy was investigated by studying the dihydropyridine receptors in transverse tubule membranes isolated from skeletal muscle of normal (line 412) and dystrophic (line 413) chickens. The yield of T-tubular protein from dystrophic muscle was considerably increased compared with that from normal muscle (2.51 +/- 0.18 vs 1.04 +/- 0.31 mg protein x 100 g muscle-1). The binding of the calcium channel antagonist (+) [3H]PN200-110 to the dihydropyridine receptor in transverse tubule preparations was relatively slow, markedly affected by temperature and required divalent cations. (+) [3H]PN200-110 equilibrium binding assays revealed a single class of high-affinity sites and showed that maximum binding capacity (Bmax) (3.17 +/- 0.47 for normal and 3.51 +/- 0.52 pmol x mg protein-1 for dystrophic transverse tubules) and dissociation constant (Kd) (0.32 +/- 0.07 and 0.26 +/- 0.09 nM, respectively) were not significantly different in normal and dystrophic membranes. Kinetic studies indicated that normal and dystrophic transverse tubules did not differ significantly in association (2.54 x 10(6) and 2.27 x 10(6) M(-1)s(-1), respectively) and dissociation (8.5 x 10(-4) and 9.3 x 10(-4)s(-1), respectively) rate constants. Since dissociation kinetics for both preparations were monoexponential under all the experimental conditions employed, no low-affinity binding sites for (+) [3H]PN200-110 could be detected in chicken transverse tubules membranes. However, immunoblot assay, using a monoclonal antibody, revealed that dystrophic transverse tubules as compared with normal membranes were enriched twofold with the alpha 1-subunit of the dihydropyridine receptor. Therefore, although dihydropyridine-binding sites were not altered in transverse tubule membranes from dystrophic chicken skeletal muscle, both the increased yield in T-tubule vesicles and the enhanced immunodetection of the alpha 1-subunit of the dihydropyridine receptor, suggest that total content in dihydropyridine receptor is higher in dystrophic than in normal muscle.

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Spontaneous opening of the acetylcholine receptor channel in developing muscle cells from normal and dystrophic mice

Franco‐Obregón

Lansman

1995

J of Neuroscience Research

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Single-channel activity was recorded from cell-attached patches on skeletal muscle cells isolated from wild-type mice and from mice carrying the dy or mdx mutations. Spontaneous openings of the nicotinic acetylcholine receptor channel (nAChR) were detected in virtually all recordings from either dy/dy or dy/+ myotubes, but only infrequently from wild-type or mdx myotubes. Spontaneous openings were also present in most recordings from undifferentiated myoblasts from all of the mouse strains studied. The biophysical properties of the spontaneous activity were similar to those of the embryonic form of the nAChR in the presence of acetylcholine (ACh). Examination of the single-channel currents evoked by low concentrations of ACh showed a reduced sensitivity to the agonist in the dystrophic dy and mdx myotubes, but not in wild-type myotubes. The results suggest that alterations in nAChR function are associated with the pathogenesis of muscular dystrophy in the dy mouse.

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Calcium regulation in muscle diseases; the influence of innervation and activity

Cited by 27 publications

References 1,025 publications

Copper toxicity in cultured human skeletal muscle cells: the involvement of Na+/K+-ATPase and the Na+/Ca2+-exchanger

Copper toxicity in cultured human skeletal muscle cells: the involvement of Na+/K+-ATPase and the Na+/Ca2+-exchanger

Dihydropyridine receptors in transverse tubules from normal and dystrophic chicken skeletal muscle

Spontaneous opening of the acetylcholine receptor channel in developing muscle cells from normal and dystrophic mice

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