Carbon dioxide, extracellular pH and fibre water in frog skeletal muscle

1982 ◽  
Vol 392 (3) ◽  
pp. 277-278 ◽  
Author(s):  
F. Huguenin
Keyword(s):  
Carbon Dioxide ◽  
Skeletal Muscle ◽  
Extracellular Ph ◽  
Frog Skeletal Muscle

The effect of acid–base changes on skeletal muscle twitch tension

1978 ◽  
Vol 56 (4) ◽  
pp. 543-549 ◽  
Author(s):  
David W. Fretthold ◽  
Lal C. Garg
Keyword(s):  
Carbon Dioxide ◽  
Skeletal Muscle ◽  
Intracellular Ph ◽  
Muscle Tension ◽  
Carbon Dioxide Tension ◽  
Extracellular Ph ◽  
Acid Base ◽  
Muscle Twitch ◽  
Deficient Diet

The effects of acid–base alterations produced by changing bicarbonate (metabolic type), carbon dioxide tension (respiratory type), or both bicarbonate and carbon dioxide tension (compensated type) on skeletal muscle twitch tension, intracellular pH, and intracellular potassium were studied in vitro. Hemidiaphragm muscles from normal rats and rats fed a potassium-deficient diet were used. Decreasing the extracellular pH by decreasing bicarbonate or increasing CO2 in the bathing fluid produced a decrease in intracellular pH, intracellular K+, and muscle twitch tension. However, at a constant extracellular pH, an increase in CO2 (compensated by an increase in bicarbonate) produced an increase in intracellular K+ and twitch tension in spite of a decrease in intracellular pH. The effect on twitch tension of the hemidiaphragms showed a rapid onset, was reversible, persisted until the buffer composition was changed, and was independent of synaptic transmission.It is concluded that the twitch tension of the skeletal muscle decreases with a decrease in intracellular K+. The muscle tension also decreases with an increase in the ratio of intracellular and extracellular H+ concentration. However, there is no consistent relationship between muscle tension and extracellular or intracellular pH. The muscle tension of the diaphragms taken from K+-deficient rats is more sensitive to variations in CO2, pH, and bicarbonate concentration of the medium than that of the control rat diaphragms.

Ultra-Rapid Freezing of Isolated Skeletal Muscle Fibers

1977 ◽  
Vol 35 ◽  
pp. 576-577
Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Granular Material ◽  
Nuclear Envelope ◽  
Intracellular Calcium ◽  
Ruthenium Red ◽  
Threshold Concentration ◽  
Rapid Freezing ◽  
Frog Skeletal Muscle ◽  
Electrical Isolation

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

Different actions of aconitine and veratrum alkaloids on frog skeletal muscle

1990 ◽  
Vol 21 (6) ◽  
pp. 863-868 ◽  
Author(s):  
Péter P. Nánási ◽  
Tamás Kiss ◽  
Miklós Dankó ◽  
David A. Lathrop
Keyword(s):  
Skeletal Muscle ◽  
Frog Skeletal Muscle ◽  
Veratrum Alkaloids
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