The effect of K+ on the recovery of the twitch and tetanic force following fatigue in the sartorius muscle of the frog, Rana pipiens

1994 ◽  
Vol 15 (4) ◽  
pp. 420-431 ◽  
Author(s):  
Jean Marc Renaud ◽  
Alain Comtois
Keyword(s):  
Rana Pipiens ◽  
Sartorius Muscle ◽  
Tetanic Force

Seasonal variation in muscle fatigue in the sartorius muscle of the frog Rana pipiens

1991 ◽  
Vol 69 (6) ◽  
pp. 1712-1715
Author(s):  
Jean Marc Renaud
Keyword(s):  
Seasonal Variation ◽  
Rana Pipiens ◽  
Recovery Period ◽  
Sartorius Muscle ◽  
Tetanic Force ◽  
Fatigue Development ◽  
Significant Seasonal Variation ◽  
Significant Difference ◽  
Force Recovery ◽  
Frog Sartorius

The goal of this study was to determine whether seasonal variation occurs in the rates of fatigue development and force recovery in the frog sartorius muscle. The data were gathered from different experiments performed during a 6-year period (1983–1989). All frog sartorius muscles were stimulated to fatigue with tetanic contractions at the rate of 1/s for 3 min. The decrease in tetanic force after 1.5 and 3 min of stimulation was relatively consistent throughout the year. The only significant difference occurred in the muscles tested in September and October, which were less fatigue resistant than those tested in December. Following fatigue, muscles were stimulated at the rate of one contraction every 100 s, so that the recovery of tetanic force could be followed. A large and significant seasonal variation was observed in the recovery period. Frog sartorius muscles tested between March and July recovered their tetanic force at a faster rate than those tested between August and October. It was shown that the highest capacity to recover force coincides with the time of the year when frogs are the most active.

scholarly journals ACTION OF POTASSIUM AND NARCOTICS ON RECTIFICATION IN NERVE AND MUSCLE

1944 ◽  
Vol 28 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Rita Guttman
Keyword(s):  
Plasma Membrane ◽  
Sciatic Nerve ◽  
Rana Pipiens ◽  
Current Flow ◽  
Barium Chloride ◽  
Resting Potential ◽  
Sartorius Muscle ◽  
Potassium Ions ◽  
Excess Calcium ◽  
Simultaneous Decrease

Electrical rectification was demonstrated in whole sartorius muscle and sciatic nerve of Rana pipiens and also in the single giant nerve fiber of the northern squid, Ommastrephes illecibrossus. It is probably a property of the plasma membrane. Rectification decreases reversibly under the influence of increased concentrations of the potassium ion and with chloroform, veratrine sulfate and isoamyl carbamate. No effect was found with lack of calcium, excess calcium, or barium chloride. Decrease in rectification is invariably accompanied by simultaneous decrease in resting potential. A proposed explanation of the mechanism of rectification is discussed. Rectification in a living membrane, viz. a change in resistance with change in direction of current flow, may possibly be explained in terms of a change in the concentration of potassium ions in the membrane.

Effects of K+ on the twitch and tetanic contraction in the sartorius muscle of the frog, Rana pipiens. Implication for fatigue in vivo

1992 ◽  
Vol 70 (9) ◽  
pp. 1236-1246 ◽  
Author(s):  
Jean Marc Renaud ◽  
Peter Light
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Muscle Fibers ◽  
Resting Potential ◽  
Sartorius Muscle ◽  
Coupling Mechanism ◽  
Tetanic Force ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
The Mean

The effects of increasing the extracellular K+ concentration on the capacity to generate action potentials and to contract were tested on unfatigued muscle fibers isolated from frog sartorius muscle. The goal of this study was to investigate further the role of K+ in muscle fatigue by testing whether an increased extracellular K+ concentration in unfatigued muscle fibers causes a decrease in force similar to the decrease observed during fatigue. Resting and action potentials were measured with conventional microelectrodes. Twitch and tetanic force was elicited by field stimulation. At pHo (extracellular pH) 7.8 and 3 mmol K+∙L−1 (control), the mean resting potential was −86.6 ± 1.7 mV (mean ± SEM) and the mean overshoot of the action potential was 5.6 ± 2.5 mV. An increased K+ concentration from 3 to 8.0 mmol∙L−1 depolarized the sarcolemma to −72.2 ± 1.4 mV, abolished the overshoot as the peak potential during an action potential was −12.0 ± 3.9 mV, potentiated the twitch force by 48.0 ± 5.7%, but did not affect the tetanic force (maximum force) and the ability to maintain a constant force during the plateau phase of a tetanus. An increase to 10 mmol K+∙L−1 depolarized the sarcolemma to −70.1 ± 1.7 mV and caused large decreases in twitch (31.6 ± 26.1%) and tetanic (74.6 ± 12.1%) force. Between 3 and 9 mmol K+∙L−1, the effects of K+ at pHo 7.2 (a pHo mimicking the change in interstitial pH during fatigue) and 6.4 (a pHo known to inhibit force recovery following fatigue) on resting and action potentials as well as on the twitch and tetanic force were similar to those at pHo 7.8. Above 9 mmol K+∙L−1 significant differences were found in the effect of K+ between pHo 7.8 and 7.2 or 6.4. In general, the decrease in peak action potential and twitch and tetanic force occurred at higher K+ concentrations as the pHo was more acidic. The results obtained in this study do not support the hypothesis that an accumulation of K+ at the surface of the sarcolemma is sufficiently large to suppress force development during fatigue. The possibility that the K+ concentration in the T tubules reaches the critical K+ concentration necessary to cause a failure of the excitation–contraction coupling mechanism is discussed.Key words: excitation–contraction coupling, fatigue, potassium, tetanus, twitch.

The effects of isotonic contractions on the rate of fatigue development and the resting membrane potential in the sartorius muscle of the frog, Rana pipiens

1991 ◽  
Vol 69 (11) ◽  
pp. 1754-1759 ◽  
Author(s):  
Jean Marc Renaud ◽  
Melvin Kong
Keyword(s):  
Relaxation Time ◽  
Resting Potential ◽  
Resting Membrane Potential ◽  
Sartorius Muscle ◽  
Tetanic Force ◽  
Fatigue Development ◽  
The Difference ◽  
Initial Difference ◽  
Isotonic Contractions ◽  
Frog Sartorius

The goal of this study was to characterize how isotonic contractions affect the rate of fatigue development. Muscle bundles dissected from frog sartorius muscles were stimulated with 100-ms long train of pulses (0.5 ms, 6 V, 140 Hz). To measure the effect of the isotonic contractions, isometric tetanus were elicited at regular time intervals during the stimulation to fatigue. In general, isotonic contractions caused a faster decrease in tetanic force than isometric contractions. The difference in tetanic force between an isotonic and isometric fatigue increased gradually over a 20-min period to 7.9 and 13.5% at 0.04 and 0.1 trains/s (TPS), respectively. At 0.2, 0.5, and 1.0 TPS, the decrease in tetanic force was also faster during an isotonic fatigue, which resulted in an initial difference in tetanic force between the two types of fatigue. The difference did not exceed 18.5% and did not persist throughout the stimulation period; i.e., the difference disappeared before the end of the fatigue stimulation. The half-relaxation time was prolonged during fatigue development, and the prolongation was greater during an isotonic fatigue, except at 0.04 TPS. The increases in the half-relaxation time at 0.2, 0.5, and 1.0 TPS were followed by a decrease, and the decreases were especially pronounced during an isotonic fatigue at 0.5 and 1.0 TPS. The results showed for the first time that isotonic contractions cause a faster rate of fatigue development in frog sartorius muscles, and this effect depends on the frequency of stimulation.Key words: muscle, fatigue, force, shortening, resting potential.

scholarly journals CALCIUM INFLUX IN SKELETAL MUSCLE AT REST, DURING ACTIVITY, AND DURING POTASSIUM CONTRACTURE

1959 ◽  
Vol 42 (4) ◽  
pp. 803-815 ◽  
Author(s):  
C. Paul Bianchi ◽  
A. M. Shanes
Keyword(s):  
Skeletal Muscle ◽  
Rana Pipiens ◽  
Calcium Influx ◽  
Nerve Fibers ◽  
Sartorius Muscle ◽  
Potassium Contracture ◽  
Anion Substitution ◽  
Cent Increase ◽  
Fast Twitch ◽  
Passive Influx

Calcium influx in the sartorius muscle of the frog (Rana pipiens) has been estimated from the rate of entry of Ca45. In the unstimulated preparation it is about equal to what has been reported for squid giant axons, but that per impulse is at least 30 times greater than in nerve fibers. The enhanced twitch when NO-2 replaces Cl- in Ringer's is associated with at least a 60 per cent increase in influx during activity, whereas this anion substitution does not affect the passive influx significantly. Calcium entry during potassium contracture is even more markedly augmented than during electrical stimulation, but only at the beginning of the contracture; thus, when a brief Ca45 exposure precedes excess K+ application, C45 uptake is increased three- to fivefold over the controls not subjected to K+, whereas when C45 and K+ are added together, no measurable increase in Ca45 uptake occurs. These findings are in keeping with the brevity of potassium contracture in "fast (twitch)" fibers such as in sartorius muscle.

scholarly journals Radiocalcium Release by Stimulated and Potassium-Treated Sartorius Muscles of the Frog

1960 ◽  
Vol 43 (3) ◽  
pp. 481-493 ◽  
Author(s):  
A. M. Shanes ◽  
C. P. Bianchi
Keyword(s):  
Electrical Stimulation ◽  
Time Course ◽  
Rana Pipiens ◽  
Calcium Release ◽  
Sartorius Muscle ◽  
Entry And Exit ◽  
Potassium Depolarization ◽  
Rate Of Escape ◽  
The Individual ◽  
Stimulation Of

Stimulation of frog (Rana pipiens) sartorius muscle accelerates release of Ca45, but only during the period of stimulation. No appreciable difference is obtained in the calcium released per impulse whether stimulation is at a rate of 20/sec. or 0.5/sec. However, prior stimulation may appreciably increase the loss per impulse. In unfatigued muscles, the minimum amount of calcium liberated during an isotonic twitch is estimated to be about that previously calculated to enter, viz. 0.2 µµmole/cm2. The time course of radiocalcium release during potassium depolarization depends on the nature of the contracture. When contracture is isometric, the rate of escape is doubled and declines only slowly; if isotonic, the rate is quadrupled but declines in a few minutes to a level maintained at about double that before potassium. The minimal calcium release during the first 10 minutes of potassium treatment is estimated to be about the same in both cases and about one-half to one-third the uptake. This, and especially the close equality of calcium entry and exit during electrical stimulation, are pointed out as not necessarily inconsistent with a transitory net entry of calcium, comparable to the influx, into restricted regions of the individual fibers.

Effect of veratridine on membrane potential of sartorius muscle from Rana pipiens

1984 ◽  
Vol 247 (5) ◽  
pp. C309-C313 ◽  
Author(s):  
L. C. McKinney
Keyword(s):  
Membrane Potential ◽  
Time Constant ◽  
Free Parameter ◽  
Rana Pipiens ◽  
Sartorius Muscle ◽  
Permeability Ratio ◽  
Donnan Equilibrium ◽  
All Solutions ◽  
Dose Dependent

The effect of veratridine on the membrane potential of sartorius muscles from Rana pipiens was studied. Membrane potential (Vm) was measured in Ringer solutions containing 2.5, 10, 30, 75, and 190 mM K+ in the absence and presence of veratridine. The product [K]o[Cl]o was kept at 300 mM2 to maintain Donnan equilibrium. External Na+ was lowered to 10 mM. Ouabain (100 microM) was present in all solutions. Vm vs. log [K]o curves were fit using the Goldman-Hodgkin-Katz equation with a single free parameter, alpha = PNa/PK (permeability ratio of Na to K). Veratridine (100 microM) causes alpha to increase 12.6 +/- 1.2-fold (n = 9), from 0.146 to 1.657. The effect of veratridine on Vm is dose dependent and reversible, with a time constant for washout of 40 min. The depolarization produced by veratridine is prevented by tetrodotoxin and by Mg, is sensitive to external Na concentration, and is insensitive to curare.

Is the change in intracellular pH during fatigue large enough to be the main cause of fatigue?

1986 ◽  
Vol 64 (6) ◽  
pp. 764-767 ◽  
Author(s):  
J. M. Renaud ◽  
Y. Allard ◽  
G. W. Mainwood
Keyword(s):  
Intracellular Ph ◽  
Extracellular Ph ◽  
Sartorius Muscle ◽  
Bathing Solution ◽  
Tetanic Contraction ◽  
Tetanic Force ◽  
Fatigue Effect ◽  
Frog Sartorius Muscle ◽  
Stimulation Period ◽  
Frog Sartorius

The intracellular pH of frog sartorius muscles exposed to an extracellular pH 8.0 (25 mM HCO3−, 1% CO2) was 6.9–7.1. Following a fatiguing stimulation period (one tetanic contraction per second for 3 min), the intracellular pH was 6.5–6.7. When similar experiments were repeated with frog sartorius muscles exposed to pH 6.4 (2 mM HCO3−, 1% CO2), the intracellular pH was 6.8–6.9 at rest and 6.3–6.4 following fatigue. So, in both experiments the intracellular pH decreased by 0.4–0.5 pH unit during fatigue. When the CO2 concentration of the bathing solution was increased from 1 to 30%, the intracellular pH of resting muscles decreased from 7.0 to 6.2–6.3. Although the effect of CO2 on the intracellular pH was greater than the fatigue effect, the decrease in tetanic force with CO2 was less than 40%, while during fatigue the tetanic force decreased by at least 70%. Therefore in frog sartorius muscle the decrease in tetanic force during fatigue exceeds the decrease that is expected from just a change in intracellular pH.

scholarly journals THE DISTRIBUTION AND KINETICS OF RELEASE OF RADIOCALCIUM IN TENDON AND SKELETAL MUSCLE

1959 ◽  
Vol 42 (5) ◽  
pp. 1123-1137 ◽  
Author(s):  
A. M. Shanes ◽  
C. P. Bianchi
Keyword(s):  
Rana Pipiens ◽  
Sartorius Muscle ◽  
Half Time ◽  
Infinite Time ◽  
Ringer’S Solution ◽  
Satisfactory Model ◽  
Rate Of Escape ◽  
Wet Weight ◽  
Kinetics Of ◽  
Uptake And Release

The distribution of Ca45 in frog (Rana pipiens) sartorius muscle, after 4 hours' exposure to Ringer's solution containing radiocalcium, has been analyzed by observing the kinetics of escape of the radioisotope into a non-radioactive Ringer's solution with calcium present or absent and by assuming that the tendon of Achilles is a satisfactory model of the extent of the uptake and release of Ca45 by the interstitial connective tissue (c.t.). In a Ringer's solution containing 1 mM/liter calcium, the exchangeable calcium distribution in micromoles per gram wet weight is as follows: (a) Aqueous phase of c.t. space: 0.16; (b) bound to c.t.: 0.16; (c) bound to surface of fibers: 0.13, of which 0.03 is displaced only by self-exchange, whereas the rest, as in c.t., can be displaced by other ions; and (d) in myoplasm: 0.33. The kinetics of Ca45 exit suggests that in infinite time of exposure to Ca45 the myoplasmic component would rise to 0.85. In the muscles, the half-time of the quickly emerging Ca45 averages about 3 minutes, whereas the time constant of the slowly released component is about 500 minutes. In the tendons the percentage rate of escape falls exponentially, the half-time of emergence being about 10 minutes.

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