Excitation-contraction coupling in frog sartorius and the role of the surface charge due to the carboxyl group of sialic acid

1979 ◽  
Vol 380 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Marianne D�rrscheidt-K�fer
Keyword(s):  
Sialic Acid ◽  
Surface Charge ◽  
Carboxyl Group ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Frog Sartorius

Possible role of the transverse tubules in accumulating calcium released from the terminal cisternae by stimulation and drugs

1982 ◽  
Vol 60 (4) ◽  
pp. 503-507 ◽  
Author(s):  
C. P. Bianchi ◽  
S. Narayan
Keyword(s):  
Kinetic Analysis ◽  
Time Constant ◽  
Transverse Tubules ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Mechanical Threshold ◽  
A New Technique ◽  
Frog Sartorius ◽  
Terminal Cisternae

The sizes of the rapidly exchanging and slowly exchanging Ca2+ pools were estimated in frog sartorius muscles. A new technique using Sr2+ to extract the rapidly exchanging pool was used. The method avoids problems of kinetic analysis. The results showed that stimulation causes Ca2+ to be translocated from a compartment which exchanges with a time constant of 800 min to a compartment that can be washed out in 15 min. This is likely a transfer from the terminal cisternae to the transverse tubule. Calculations show that this would represent 0.9% of the Ca2+ released in each twitch. After 300 twitches produced by a 1-Hz stimulation, this accumulation could have increased the Ca concentration in the transverse tubules to 70 mM. A marked increase of Ca2+ concentration of this magnitude in the transverse tubules would raise the mechanical threshold for excitation–contraction coupling and would decrease the efficiency of coupling between contraction and excitation. This could be the explanation of the fatigue observed during this kind of stimulation.

Extracellular divalent cations in excitation–contraction coupling: hypertonic solution effects

1982 ◽  
Vol 60 (4) ◽  
pp. 440-445
Author(s):  
Isao Oota ◽  
Isao Kosaka ◽  
Torao Nagai ◽  
Hideyo Yabu
Keyword(s):  
Skeletal Muscle ◽  
Divalent Cations ◽  
Muscle Fibers ◽  
Hypertonic Solution ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Skeletal Muscle Fibers ◽  
Membrane Bound

It is the purpose of this article to point out that the membrane-bound Ca plays an important role in excitation–contraction (E–C) coupling of skeletal muscle fibers and that other divalent cations are unable to substitute for this role of membrane-bound Ca.

Excitation-contraction coupling in HFpEF versus HFrEF: Role of transverse-axial tubule system

2020 ◽  
Vol 140 ◽  
pp. 46
Author(s):  
Xin Yue ◽  
Peter Kilfoil ◽  
Rui Zhang ◽  
Stephan Aynaszyan ◽  
Yushun Zhang ◽  
...  
Keyword(s):  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Transverse Axial
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