Effect of temperature and Zn2+ on isometric contractile properties and electrical phenomena of frog (Rana) and Xenopus skeletal muscle fibers

1984 ◽  
Vol 62 (12) ◽  
pp. 1511-1517 ◽  
Author(s):  
Toshiharu Oba ◽  
Yumiko Takagi ◽  
Ken Hotta
Keyword(s):  
Action Potential ◽  
Rana Catesbeiana ◽  
Muscle Fibers ◽  
Contractile Properties ◽  
Effect Of Temperature ◽  
Duration Of Action ◽  
Time To Peak ◽  
Effects Of Temperature ◽  
Maximum Rate Of Rise ◽  
Tubular Morphology

Effects of temperature and Zn2+ on the isometric contractile properties of toe muscle fibers of Rana catesbeiana and Xenopus laevis were studied. The maximum twitch tension almost doubled when the temperature was lowered from 20 to 4 °C in Rana muscles but not in Xenopus muscles, although the duration of action potential in Xenopus muscle was increased slightly more than that seen in the Rana species. The maximum rate of rise of tension was greater in Xenopus muscle than in the Rana muscle, at 20 °C. The prolongation of the time-to-peak tension following exposure to low temperature (4 °C) was more pronounced in Rana than in Xenopus muscles. These results suggest that the speed of release and reuptake of Ca2+ by the sarcoplasmic reticulum (SR) differs in Rana and Xenopus muscles and that these factors may be related to differences in the SR and the T-tubular morphology. In Rana muscles, Zn2+ prolonged the falling phase of the action potential and potentiated the twitch tension. In Xenopus muscles, Zn2+ marginally prolonged the duration of action potential and the twitch tension was not markedly potentiated. These results indicate that Zn2+ potentiates the twitch tension by prolonging the action potential and that Rana muscles are more sensitive to the effects of Zn2+.

Inhibition of Zn2+-induced potentiation of twitch tension by Ni2+ in frog muscle

1986 ◽  
Vol 64 (5) ◽  
pp. 625-630
Author(s):  
Toshiharu Oba ◽  
Ken Hotta
Keyword(s):  
Action Potential ◽  
Inhibitory Action ◽  
Channel Blocker ◽  
Rana Catesbeiana ◽  
Muscle Fibers ◽  
Frog Muscle ◽  
Duration Of Action ◽  
Ringer’S Solution ◽  
Mechanical Threshold ◽  
T Tubules

Effect of Ni2+ on Zn2+-induced potentiation of twitch tension was studied electrophysiologically in the toe muscle fibers of Rana catesbeiana. The major findings of this investigation are as follows. When 2 mM Ni2+ was applied to fibers in a normal Ringer's solution containing 50 μM Zn2+ (Zn2+ solution), the Zn2+-potentiated twitch tension decreased remarkably to about one-third of that before Ni2+ treatment. This concentration of Ni2+ caused a 23% decrease in the duration of action potential which had been prolonged by Zn2+ (6.61–5.09 ms). Ni2+ (2 mM) added to normal Ringer's solution led to increases of about 30 and 42% in twitch tension and in the duration of action potential, respectively. A slight increase in the mechanical threshold was induced by 2 mM Ni2+. The inhibitory action of Ni2+ on the twitch tension in Zn2+ solution was larger than that in the case of tetanus tension. Diltiazem (40 μM), aCa2+ channel blocker, did not inhibit the twitch tension potentiated in Zn2+ solution. These results suggest that the decrease in Zn2+-potentiated twitch tension by Ni2+ may possibly derive from impairment of the propagation of action potential along the T tubules.

scholarly journals The effect of temperature on spontaneous action potential discharge of the isolated sinus venosus from winter and summer plaice (Pleuronectes platessa)

1995 ◽  
Vol 198 (1) ◽  
pp. 137-140 ◽  
Author(s):  
A A Harper ◽  
I P Newton ◽  
P W Watt
Keyword(s):  
Action Potential ◽  
Discharge Rate ◽  
Cardiac Pacemaker ◽  
Intrinsic Rate ◽  
Effect Of Temperature ◽  
Pacemaker Activity ◽  
Duration Of Action ◽  
Diastolic Depolarization ◽  
Significant Difference

The spontaneous cardiac pacemaker activity and conformation were recorded in vitro, using intracellular recording methods, from heart tissue of summer- and winter-caught plaice. The effects of changing temperature on the pacemaker rate, duration of action potential and diastolic depolarization were investigated by altering the temperature of the superfusing medium. The resting intrinsic rate of discharge was significantly greater in pacemaker cells from winter plaice (P=0.05), but there was no significant difference between winter and summer fish in the apparent Arrhenius activation energies for this process. However, there was a significant difference in the estimated intercept, indicating a thermal shift in the processes underlying the spontaneous pacemaker rhythm. There was no significant difference in the diastolic depolarization duration recorded from winter and summer fish over the temperature range 4­22 °C. The major effect of previous environmental temperature was on the duration of the action potential (P<0.02), indicating that the observed changes in pacemaker discharge rate were not influenced by the processes that determine the duration of the pacemaker diastolic depolarisation but were modulated by the channel events that give rise to the action potential.

Effect of temperature on intracellular pH in crayfish neurons and muscle fibers

1984 ◽  
Vol 246 (1) ◽  
pp. C45-C49 ◽  
Author(s):  
J. L. Rodeau
Keyword(s):  
Intracellular Ph ◽  
Muscle Fibers ◽  
Effect Of Temperature ◽  
Cellular Regulation ◽  
Acid Base ◽  
Astacus Leptodactylus ◽  
Acid Base Status ◽  
Effects Of Temperature ◽  
Ph Microelectrodes

Intracellular pH microelectrodes were used to determine the effects of temperature (13-26 degrees C) on the in vitro regulation of intracellular acid-base status of neurons and muscle fibers of the crayfish Astacus leptodactylus. The values of the temperature coefficients delta pH/delta T (pH unit/degrees C) were -0.019 and -0.026 for muscles and neurons, respectively, values which are close to the temperature coefficient (-0.019) of the pK' of protein imidazole buffer groups. When temperature varies, the dissociation ratio of imidazole groups is thus maintained by the cellular regulation of cytoplasmic pH. According to the alphastat regulation hypothesis, this constancy would minimize the temperature effects on enzymic systems.

The Effects of Temperature on Flight Muscle Potentials in Honeybees and Cuculiinid Winter Moths

1988 ◽  
Vol 135 (1) ◽  
pp. 109-117 ◽  
Author(s):  
HARALD ESCH
Keyword(s):  
Apis Mellifera ◽  
Action Potential ◽  
Rise Time ◽  
Action Potentials ◽  
Flight Muscle ◽  
Duration Of Action ◽  
Apis Mellifera Mellifera ◽  
Winter Moth ◽  
Flight Muscles ◽  
Effects Of Temperature

Amplitudes of extracellular action potentials in indirect flight muscles of honeybees and cuculiinid winter moths decline with decreasing muscle temperatures and fall suddenly to zero. Action potential durations increase with amplitude decline. Amplitudes at 11°C are only 20% of values near 30°C in workers of Apis mellifera mellifera. They fall to zero at approx. 10°C. In the cuculiinid winter moth Eupsilia devia, amplitudes at 1°C are approx. 12% of values at 27°C. They fall to zero between 0 and 1°C. The duration of action potentials in bees and cuculiinid winter moths is about 7 ms at 27°C and increases to 52 ms at 11°C in bees and to 66 ms at 1°C in moths. The ratios of action potential rise time to fall time are about 1 at 27°C for bees and moths. They decrease to 0.45 at 11°C in bees and to 0.56 at 1°C in moths. Results suggest that bees can heat flight muscles only if muscle temperatures are above 10°C, whereas cuculiinid winter moths can shiver with muscle temperatures near 0°C.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

Krüppel‐like factor 10 regulates the contractile properties of skeletal muscle fibers in mice

2021 ◽  
Author(s):  
Malek Kammoun ◽  
Philippe Pouletaut ◽  
Sandrine Morandat ◽  
Malayannan Subramaniam ◽  
John R. Hawse ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Contractile Properties ◽  
Skeletal Muscle Fibers

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

Enhanced thermoelectric performance of layered SnS crystals: the synergetic effect of temperature and carrier concentration

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 56382-56390 ◽  
Author(s):  
Bao-Zhen Sun ◽  
Zuju Ma ◽  
Chao He ◽  
Kechen Wu
Keyword(s):  
Carrier Concentration ◽  
Synergetic Effect ◽  
Thermoelectric Performance ◽  
Effect Of Temperature ◽  
Effects Of Temperature

The synergistic deployment of the effects of temperature and carrier concentration raises the ZT of SnS to a high value (1.61 ± 0.02).

scholarly journals Studies in the geotropism of the pteridophyta V—Some effects of temperature on growth and geotropism in Asplenium bulbiferium

1935 ◽  
Vol 116 (800) ◽  
pp. 479-493 ◽  
Keyword(s):  
Growth Rate ◽  
Effect Of Temperature ◽  
Horizontal Position ◽  
Present Position ◽  
Minimum Period ◽  
Plant Life ◽  
Latent Time ◽  
Presentation Time ◽  
Effects Of Temperature ◽  
The Given

Although temperature and gravity both influence plant life, and although both factors have been studied for many decades, there is surprisingly little literature decades, there is surprisingly little literature dealing with the relation between the two; and none, so far as I can discover, on the effect in any Pteridophyte. Navez (1929) who criticized the work of some investigators on the effect of temperature on the geotropism of a few seedlings, sums up the present position in his remark that the conclusions of workers are very different and often in opposition. The present paper gives the results of 1100 experiments carried out mainly between the years 1922 and 1927, and though it is realized that much remains to be done on the question, it is believed that the results which have been obtained are of some value. For general methods, reference may be made to previous “Studies” in this series. Geotropic sensitivity, as measured by presentation time at different stages in development of the frond, was fully worked out by Waight (1923) for 20°C, and is adopted here as a standard of reference. The growth rate recorded in the tables is that for the particular frond under investigation, or is the average of the fronds examined during the day of the experiment. Nearly all the experiments included in the tables were conducted during the months of April-October, as I have since been able to show that there is an annual rhythm in geotropic irritability. A decrease in sensitivity occurs in winter, and hence experiments performed in November-March are not strictly comparable with those carried out in the summer. The following abbreviations are used:- P.S. = period of stimulation. P.T. = presentation time, i. e ., the minimum period of stimulation in a horizontal position, which, under the given conditions, will cause a movement of approximately 5° in about 80% of the fronds. L.T. = latent time (Prankerd, 1925) in hours. N = “normal time,” i. e ., the P.T. For different stages of the frond at 20°C (see Waight, 1923).

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