Calcium binding to the sarcoplasmic reticulum of rabbit skeletal muscle

Biochemistry ◽  
1971 ◽  
Vol 10 (14) ◽  
pp. 2733-2737 ◽  
Author(s):  
Ronald A. Butow ◽  
Jean Chevallier
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Rabbit Skeletal Muscle

scholarly journals Calcium-Binding Properties of Sarcoplasmic Reticulum As Influenced by ATP, Caffeine, Quinine, and Local Anesthetics

1968 ◽  
Vol 52 (4) ◽  
pp. 622-642 ◽  
Author(s):  
Arselio P. Carvalho
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Binding Sites ◽  
Local Anesthetics ◽  
Calcium Binding ◽  
Rabbit Skeletal Muscle ◽  
Cellular Membranes ◽  
Binding Properties ◽  
45Ca Fluxes

Calcium retained at binding sites of the sarcoplasmic reticulum membranes isolated from rabbit skeletal muscle requires 10-5 - 10-4 M ATP to exchange with 45Ca added to the medium. The ATP requirement for Ca exchangeability was observed with respect to the "intrinsic" Ca of the reticulum membranes and the fraction of Ca that is "actively" bound in the presence of ATP. Furthermore, a concentration of free Ca in the medium higher than 10-8 M is required for ATP to promote Ca exchangeability. This exchangeability is not influenced by caffeine, quinine, procaine, and tetracaine, and Ca that is either nonexchangeable (in the absence of ATP) or exchangeable (in the presence of ATP) is released by 1–5 mM quinine or tetracaine, but neither caffeine (6 mM) nor procaine (2–5 mM) has this effect. Quinine or tetracaine also releases Ca and Mg bound passively to the reticulum membranes. A possible role of ATP in maintaining the integrity of cellular membranes is discussed, and the effects of caffeine, quinine, and of local anesthetics on the binding of Ca by the isolated reticulum are related to the effects of these agents on 45Ca fluxes and on the twitch output observed in whole muscles.

scholarly journals Calcium-Binding Properties of Sarcoplasmic Reticulum As Influenced by ATP, Caffeine, Quinine, and Local Anesthetics

1968 ◽  
Vol 52 (3) ◽  
pp. 622-642 ◽  
Author(s):  
Arselio P. Carvalho
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Binding Sites ◽  
Local Anesthetics ◽  
Calcium Binding ◽  
Rabbit Skeletal Muscle ◽  
Cellular Membranes ◽  
Binding Properties ◽  
45Ca Fluxes

Calcium retained at binding sites of the sarcoplasmic reticulum membranes isolated from rabbit skeletal muscle requires 10-5 – 10-4 M ATP to exchange with 45Ca added to the medium. The ATP requirement for Ca exchangeability was observed with respect to the "intrinsic" Ca of the reticulum membranes and the fraction of Ca that is "actively" bound in the presence of ATP. Furthermore, a concentration of free Ca in the medium higher than 10-8 M is required for ATP to promote Ca exchangeability. This exchangeability is not influenced by caffeine, quinine, procaine, and tetracaine, and Ca that is either nonexchangeable (in the absence of ATP) or exchangeable (in the presence of ATP) is released by 1–5 mM quinine or tetracaine, but neither caffeine (6 mM) nor procaine (2–5 mM) has this effect. Quinine or tetracaine also releases Ca and Mg bound passively to the reticulum membranes. A possible role of ATP in maintaining the integrity of cellular membranes is discussed, and the effects of caffeine, quinine, and of local anesthetics on the binding of Ca by the isolated reticulum are related to the effects of these agents on 45Ca fluxes and on the twitch output observed in whole muscles.

scholarly journals Drastic reduction of calsequestrin-like proteins and impaired calcium binding in dystrophic mdx muscle

2002 ◽  
Vol 92 (2) ◽  
pp. 435-445 ◽  
Author(s):  
Kevin Culligan ◽  
Niamh Banville ◽  
Paul Dowling ◽  
Kay Ohlendieck
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Muscular Dystrophy ◽  
Calcium Binding ◽  
Functional Decline ◽  
Two Dimensional ◽  
Drastic Reduction ◽  
Dystrophic Muscle ◽  
One Dimensional ◽  
Blotting Technique

Although the reduction in dystrophin-associated glycoproteins is the primary pathophysiological consequence of the deficiency in dystrophin, little is known about the secondary abnormalities leading to x-linked muscular dystrophy. As abnormal Ca2+ handling may be involved in myonecrosis, we investigated the fate of key Ca2+ regulatory membrane proteins in dystrophic mdx skeletal muscle membranes. Whereas the expression of the ryanodine receptor, the dihydropyridine receptor, the Ca2+-ATPase, and calsequestrin was not affected, a drastic decline in calsequestrin-like proteins of 150–220 kDa was observed in dystrophic microsomes using one-dimensional immunoblotting, two-dimensional immunoblotting with isoelectric focusing, diagonal two-dimensional blotting technique, and immunoprecipitation. In analogy, overall Ca2+ binding was reduced in the sarcoplasmic reticulum of dystrophic muscle. The reduction in Ca2+ binding proteins might be directly involved in triggering impaired Ca2+ sequestration within the lumen of the sarcoplasmic reticulum. Thus disturbed sarcolemmal Ca2+ fluxes seem to influence overall Ca2+homeostasis, resulting in distinct changes in the expression profile of a subset of Ca2+ handling proteins, which might be an important factor in the progressive functional decline of dystrophic muscle fibers.

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