<span style="font-size:15.0pt;mso-bidi-font-size:16.0pt;font-weight:normal" lang="EN-US">Analysis of osmotic stress induced Ca<sup>2+</sup> spark termination <span style="font-size:15.0pt;mso-bidi-font-size:16.0pt;mso-ansi-language: EN-GB;font-weight:normal" lang="EN-GB">in mammalian skeletal muscle<span style="font-size:15.0pt; mso-bidi-font-size:16.0pt;font-weight:normal" lang="EN-US"> </span></span></span>
NOPR - NISCAIR Online Periodicals Repository
View Archive InfoField | Value | |
Title |
Analysis of osmotic stress induced Ca2+ spark termination in mammalian skeletal muscle
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Creator |
Ferrante, Christopher
Szappanos, Henrietta Csernoch, László Weisleder, Noah |
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Subject |
Calcium
Ca2+ Sparks Calcium induced calcium release Sarcoplasmic reticulum Skeletal muscle Termination |
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Description |
411-418
Ca2+ sparks represent synchronous opening of the ryanodine receptor (RyR) Ca2+ release channels located at the sarcoplasmic reticulum (SR) membrane. Whereas a quantal nature of Ca2+ sparks has been defined in cardiac muscle, the regulation of Ca2+ sparks in skeletal muscle has not been well-studied. Osmotic-stress applied to an intact skeletal muscle fiber can produce brief Ca2+ sparks and prolonged Ca2+ burst events. Here, we show that termination of Ca2+ bursts occurs in a step wise and quantal manner. Ca2+ burst events display kinetic features that are consistent with the involvement of both stochastic attrition and coordinated closure of RyR channels in the termination of SR Ca2+ release. Elemental unitary transition steps could be defined with a mean DF/F0 of ~0.28, corresponding to the gating of 1-2 RyR channels. Moreover, the amplitude of the elemental transition steps declines at the later stage of the burst event. In tandem Ca2+ burst events where two Ca2+ bursts occur at the same position within a fiber in rapid succession, the trailing event is consistently of lower amplitude than the initial event. These two complementary results suggest that SR Ca2+ release may be associated with local depletion of SR Ca2+ stores in mammalian skeletal muscle. |
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Date |
2013-10-26T10:00:29Z
2013-10-26T10:00:29Z 2013-10 |
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Type |
Article
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Identifier |
0975-0959 (Online); 0301-1208 (Print)
http://hdl.handle.net/123456789/22651 |
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Language |
en_US
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Rights |
CC Attribution-Noncommercial-No Derivative Works 2.5 India
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Publisher |
NISCAIR-CSIR, India
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Source |
IJBB Vol.50(5) [October 2013]
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