Silver ion-induced tension development and membrane depolarization in frog skeletal muscle fibres

1985 ◽  
Vol 405 (4) ◽  
pp. 354-359 ◽  
Author(s):  
Toshiharu Oba ◽  
Ken Hotta
Keyword(s):  
Skeletal Muscle ◽  
Membrane Depolarization ◽  
Silver Ion ◽  
Muscle Fibres ◽  
Frog Skeletal Muscle ◽  
Tension Development ◽  
Skeletal Muscle Fibres

Ba2+ ions block K+-induced contractures by antagonizing K+-induced membrane depolarization in frog skeletal muscle fibres

1982 ◽  
Vol 60 (1) ◽  
pp. 47-51 ◽  
Author(s):  
George B. Frank ◽  
Farrokh Rohani
Keyword(s):  
Skeletal Muscle ◽  
Membrane Depolarization ◽  
Membrane Potentials ◽  
Ion Concentration ◽  
Sartorius Muscle ◽  
Muscle Fibres ◽  
Frog Skeletal Muscle ◽  
Induced Membrane ◽  
Ringer’S Solution ◽  
Skeletal Muscle Fibres

The effects of Ba2+ ions on twitches. K+-induced contractures, and on intracellularly recorded membrane potentials (Em) and depolarizations of frog skeletal muscle fibres were investigated. Exposure of toe muscles to choline–Ringer's solution with 10−3 M Ba2+ with Ca2+ (1.08 mM) eliminated or very greatly reduced contractures produced by 60 mM K+. In contrast, not only did the same concentration of Ba2+ ions fail to depress the twitch tension of isolated semitendinosus fibres when added to Ringer's with Ca2+, but it even restored twitches that had been eliminated in a zero Ca2+ Ringer's solution. The resting Em of sartorius muscle fibres in choline–Ringer's solution was reduced about 20 mV by 10−3 M Ba2+. This Ba2+ ion concentration also antagonized the K+-induced depolarization. Thus in the presence of 1 mM Ba2+, 20 mM K+ hyperpolarized rather than depolarized the fibres and 60 or 123 mM K+ produced only very slowly developing, small depolarizations. These results suggest that the loss of the K+-induced contracture in choline–Ringer's caused by Ba2+ ions is due to an inhibition of the K+-induced depolarization. The latter result is consistent with previous findings of other workers that Ba2+ ions block membrane K+ channels.not available

Electromechanical Coupling II. The Effect of Perchlorate Upon Excitation-Contraction Coupling in Frog Skeletal Muscle Fibres

1982 ◽  
Vol 37 (7-8) ◽  
pp. 707-708
Author(s):  
Michael Gomolla ◽  
Gernot Gottschalk ◽  
Hans-Christoph Lüttgau
Keyword(s):  
Skeletal Muscle ◽  
Electromechanical Coupling ◽  
Muscle Fibres ◽  
Frog Skeletal Muscle ◽  
Large Shift ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Inactivation Process ◽  
Skeletal Muscle Fibres ◽  
Kinetics Of

Abstract In single skeletal muscle Fibres perchlorate causes a large shift of the potential dependence of contraction activation to more negative potentials without a corresponding alteration in the kinetics of the inactivation process.

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