scholarly journals Effects of temperature on tension, tension-dependent heat, and activation heat in twitches of frog skeletal muscle.

1979 ◽  
Vol 291 (1) ◽  
pp. 265-275 ◽  
Author(s):  
J A Rall
Keyword(s):  
Skeletal Muscle ◽  
Frog Skeletal Muscle ◽  
Effects Of Temperature ◽  
Activation Heat

scholarly journals Effects of previous activity on the energetics of activation in frog skeletal muscle.

1980 ◽  
Vol 75 (6) ◽  
pp. 617-631 ◽  
Author(s):  
J A Rall
Keyword(s):  
Skeletal Muscle ◽  
Time Delay ◽  
Time Course ◽  
Frog Skeletal Muscle ◽  
Active Force ◽  
Force Development ◽  
Uptake Sites ◽  
Contractile Activation ◽  
Terminal Cisternae ◽  
Activation Heat

Effects of previous activity on the ability of frog skeletal muscle at 0 degrees C to liberate energy associated with contractile activation, i.e., activation heat (AH), have been examined. Earlier work suggests that activation heat amplitude (as measured from muscles stretched to lengths where active force development is nearly abolished) is related to the amount of Ca2+ released upon stimulation. After a twitch, greater than 2 s is required before a second stimulus (AHt) can liberate the same activation heat as a first stimulus (AH infinity), i.e., (AHt)/(AH infinity) = 1 -0.83 e-1.40t, where t is time in seconds. Caffeine introduces a time delay in the recovery of the ability to generate activation heat after a twitch. After a tetanus, the activation heat is depressed to a greater extent at any time than after a twitch. The activation heat elicited by a stimulus 1 s after a tetanus is depressed progressively with respect to tetanus duration up to 3 s. For tetani of 3, 40, and 80 s duration the postetanus activation heat is comparably depressed. The time-course of the recovery of the ability of the muscle to produce activation heat after a tetanus can be described as (AHt)/(AH infinity) = 1 -0.80 e-0.95t -0.20 e-0.02t. Greater than 90 s is required before the posttetanus activation heat is equal to the pretetanus value. The faster phase of recovery is similar to recovery after the twitch and the slower phase may be associated with the return of calcium to the terminal cisternae from uptake sites in the longitudinal sarcoplasmic reticulum.

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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