The effect of temperature on the tension responses of the anterior byssal retractor muscle (abrm) of Mytilus edulis

1982 ◽  
Vol 97 (1) ◽  
pp. 375-384
Author(s):  
C. M. Linehan
Keyword(s):  
Ambient Temperature ◽  
Latent Period ◽  
Mytilus Edulis ◽  
Effect Of Temperature ◽  
Retractor Muscle ◽  
Tension Development ◽  
Maximum Tension ◽  
Peak Tension ◽  
The Relationship ◽  
Anterior Byssal Retractor Muscle

The effect of ambient temperature on the response of the ABRM of Mytilus edulis to acetylcholine and 5-hydroxytryptamine has been examined. As the ambient temperature was increased, the latent period and the maximum tension developed decreased while the rate of tension development and the rate of relaxation increased. The relationship between temperature and the rate of tension development showed three distinct linear phases from 2–25, 25-35 and 35-45 degrees C. The reduction in peak tension with temperature could also be resolved into three portions from 2–25, 25-40 and above 40 degrees C. As the temperature was increased above approximately 27 degrees C the rate of relaxation in the absence of 5-HT approached the rate of relaxation in the presence of 5-HT. The significance of these results and possible explanations for them are considered.

Active state plateau and latency in mammalian striated muscle

1961 ◽  
Vol 200 (4) ◽  
pp. 667-671 ◽  
Author(s):  
Forbes H. Norris
Keyword(s):  
Latent Period ◽  
Striated Muscle ◽  
Muscle Length ◽  
Single Stimulus ◽  
Active State ◽  
Tension Development ◽  
Maximum Tension ◽  
Tension Curves ◽  
Tetanic Tension

The active state plateau in rat striated muscle was studied by superimposition of tension curves resulting from one and two stimuli. The plateau ends 4.0 ± 0.1 msec. after stimulation in rat striated muscle at 36°C. The time to the end of the plateau is 3.4 ± 0.1 times the latent period. During the plateau, response to a second stimulus appears after increased mechanical latency. The second stimulus can also result in tension development at rates nearly twice those reached after a single stimulus. This effect has a peak which about corresponds to the end of the active state plateau, but precedes the peak of the curve for maximum tension. Correct timing of the second stimulus can result in about 60% of tetanic tension. The use of thiopental, gallamine, tubocurarine and changes in muscle length did not affect these results.

Sperrtonus und Nucleosidtriphosphate

1963 ◽  
Vol 18 (2) ◽  
pp. 133-138 ◽  
Author(s):  
J. C. Rüegg ◽  
Erna Strassner
Keyword(s):  
Skeletal Muscle ◽  
Mytilus Edulis ◽  
Retractor Muscle ◽  
Atp Content ◽  
Wet Weight ◽  
Anterior Byssal Retractor Muscle ◽  
Vertebrate Skeletal Muscle

The resting anterior byssal retractor muscle of Mytilus edulis (ABRM) contains 1 -1.2 μmol ATP and 0.6 - 0.8 μmol ADP per g wet weight, traces of AMP and 0.1 - 0.2 μmol GTP plus UTP. The ATP content and the ratio of ADP : ATP remains almost constant during contraction, catch and subsequent serotonin induced relaxation, IMP could not be detected, not even during thaw contracture. Consequently the catch (viscous tone, fused state) is a reversible rigor distinct from rigor in vertebrate skeletal muscle which is caused by ATP deficiency. ATP produces a very much stronger contraction in isolated actomyosin systems of ABRM than UTP, ITP and GTP.

scholarly journals Tonic contraction and the control of relaxation in a chemically skinned molluscan smooth muscle.

1982 ◽  
Vol 79 (5) ◽  
pp. 821-834 ◽  
Author(s):  
F Cornelius
Keyword(s):  
Muscle Length ◽  
Tonic Contraction ◽  
Active State ◽  
Retractor Muscle ◽  
Muscle Preparation ◽  
Tension Development ◽  
Maximum Tension ◽  
Skinned Muscle ◽  
Catch State ◽  
Molluscan Smooth Muscle

The same functional states that characterize the living anterior byssus retractor muscle (ABRM) from Mytilus edulis can be initiated in the saponin-treated (chemically skinned) muscle preparation under controlled biochemical conditions. A tonic contraction was induced if the concentration of free Ca2+ was above approximately 10(7) M in the presence of Mg2+ and ATP. Maximum tension development was achieved at a Ca2+ concentration of approximately 10(4) M. Within these Ca2+ concentrations tension was always associated with the presence of 'active state," as indicated by a high recovery of tension after a quick release in muscle length. Tonic tension, and the associated active state was maintained for hours during these conditions irrespective of variations in both ionic strength and pH. Reduction of the Ca2+ concentration to below threshold for tension initiation during a tonic contraction immediately switched off the active state and relaxation of the muscle preparation resulted. However, the rate of relaxation was extremely low, leaving a substantial fraction of tension in the absence of active state. Both 5-hydroxytryptamine (5-HT) and cAMP accelerated this slow relaxation in the absence of Ca2+. Thus, this state was considered equivalent to the 'catch state" in the living ABRM. In the presence of Ca2+ concentrations above 10(7) M, cAMP did not affect either the maximum tension developed or the Ca2+ sensitivity of the chemically skinned muscle preparation.

scholarly journals The regulation of tension in a chemically skinned molluscan smooth muscle: effect of Mg2+ on the Ca2+-activated tension generation.

1980 ◽  
Vol 75 (6) ◽  
pp. 709-725 ◽  
Author(s):  
F Cornelius
Keyword(s):  
Active State ◽  
Retractor Muscle ◽  
Striated Muscles ◽  
Free Concentration ◽  
Tension Development ◽  
Maximum Tension ◽  
Tension Level ◽  
Catch State ◽  
Complicated Model ◽  
Triton X

Chemically skinned anterior byssus retractor muscle (ABRM) preparations were prepared by treatment with the nonionic detergents saponin and Triton X-100. Both maximum peak tension and rate of contraction were found to be greater in saponin-treated ABRM than in ABRM treated with Triton X-100. Active tension was initiated at a concentration of free Ca2+ above 0.1 microM, and maximum tension development was found at a [Ca2+] = approximately 32 microM. During exposure of the muscle preparation to optimal Ca2+ concentration, a high and almost constant tension level was sustained. The force recovery was high after a quick release during this period indicating the presence of an "active" state rather than a "catch" state. Actually, a state equivalent to the catch state in the living ABRM could not be induced, if the Ca2+ concentration was above 0.1 microM. Variations in the ionic strength in the range of 0.07--0.28 M had no influence on active state and only slightly affected the maximum tension developed. The influence of Mg2+ on the Ca2+-activated tension was examined by studying the tension-pCa relation at two concentrations of free Mg2+ (0.43 and 4.0 mM). The tension-pCa relation was found to be S-shaped with tension increasing steeply over approximately 1 pCa unit, indicating the existence of cooperativity between Ca2+ sites. Increasing the free concentration of Mg2+ shifted the tension-pCa relation to lower pCa as in striated muscles, demonstrating a decreasing Ca2+ sensitivity with increasing Mg2+. At [Mg2+] = 4.0 mM the half-maximum tension was found at [Ca2+] = 0.43 microM, decreasing to 0.20 microM at [Mg2+] = 0.43 mM. At both Mg2+ concentrations studied, plots of log Prel/(1--Prel) vs. log [Ca2+] were nonlinear with a shape indicating a rather complicated model for cooperativity, probably involving four sites for Ca2+. These Ca2+--Mg2+ interactions are most probably taking place at the myosin head itself because troponin is absent in this myosin-regulated muscle.

scholarly journals Effect of ambient temperature on outpatient admission for osteoarthritis and rheumatoid arthritis in a subtropical Chinese city

2020 ◽  
Author(s):  
Desheng Zhao ◽  
Jian Cheng ◽  
Ping Bao ◽  
Yanwu Zhang ◽  
Fengjuan Liang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Ambient Temperature ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Individual Characteristics ◽  
Effect Of Temperature ◽  
Temperature Decrease ◽  
Distributed Lag ◽  
The Impact ◽  
The Relationship

Abstract Background Current findings on the impact of weather conditions on osteoarthritis (OA) and rheumatoid arthritis (RA) are sparse and not conclusive. This study aimed to investigate the relationship between temperature change and OA/RA admission. Methods Daily OA/RA admission and meteorological data from 1 January 2014 to 31 December 2017 in Hefei, China, were collected. We quantified the relationship between ambient temperature and OA/RA admission using a distributed lag nonlinear model (DLNM). The effect modifications by gender and age were also examined. Results Sudden temperature decrease was significantly associated with RA admission (25th percentile of temperature versus 50th percentile of temperature), with the acute and largest effect at current days lag (RR: 1.063, 95%CI: 1.010–1.118). However, no association between temperature and OA admission was observed. When conducting subgroup analyses by individual characteristics, we found that females and patients aged 41–65 years were more vulnerable to temperature decrease than males, patients aged 0–40 and ≧ 66 years, respectively. Conclusions This study suggested that sudden temperature decrease was a risk factor for increase RA admission. Females and patients aged 41–65 years were particularly vulnerable to the effect of temperature decrease.

Effect of acclimation temperature and pH on contraction of frog sartorius muscle

1981 ◽  
Vol 240 (5) ◽  
pp. R301-R309 ◽  
Author(s):  
J. M. Renaud ◽  
E. D. Stevens
Keyword(s):  
Relaxation Time ◽  
Latent Period ◽  
Acclimation Temperature ◽  
Sartorius Muscle ◽  
Maximum Acceleration ◽  
Tension Development ◽  
Maximum Tension ◽  
Rate Maximum ◽  
Isometric Twitch

The effect of acclimation temperature and pH on the isometric twitch and tetanus of sartorius muscle from frog, Rana pipiens, was studied at different experimental temperatures. Seven variables were measured, namely: tension, latent period, time to maximum tension, half-relaxation time, mean rate, maximum rate, and maximum acceleration of tension development. The effect of experimental temperature was similar to that reported in the literature. The effects of acclimation temperature were small and were not compensatory. Different pH's were obtained by varying CO2 in the gas phase, while the HCO3- concentration was kept constant. The main effects of a decrease in pH on the isometric twitch and tetanus were a reduction in tension and rate of tension development and an increase in latent period. A decrease in pH had no effect on the time to maximum tension or the half-relaxation time. Analysis of variance showed that the test temperature had the greatest effect of all three treatments on each variable, the effects of test and acclimation temperature were dependent on neither the test nor the acclimation temperatures. The in vivo relationships between these three treatments are discussed.

scholarly journals Depolarization-contraction coupling in short frog muscle fibers. A voltage clamp study.

1984 ◽  
Vol 84 (1) ◽  
pp. 133-154 ◽  
Author(s):  
C Caputo ◽  
F Bezanilla ◽  
P Horowicz
Keyword(s):  
Muscle Fibers ◽  
Tension Development ◽  
Contraction Coupling ◽  
Maximum Tension ◽  
Peak Tension ◽  
Relaxation Phase ◽  
Time To Peak ◽  
Intracellular Ca ◽  
Charge Movements ◽  
Internal Potential

Short muscle fibers (1.5 mm) were dissected from hindlimb muscles of frogs and voltage clamped with two microelectrodes to study phenomena related to depolarization-contraction coupling. Isometric myograms obtained in response to depolarizing pulses of durations between 10 and 500 ms and amplitudes up to 140 mV had the following properties. For suprathreshold pulses of fixed duration (in the range of 20-100 ms), the peak tension achieved, the time to peak tension, and contraction duration increased as the internal potential was made progressively more positive. Peak tension eventually saturates with increasing internal potentials. For pulse durations of greater than or equal to 50 ms, the rate of tension development becomes constant for increasing internal potentials when peak tensions become greater than one-third of the maximum tension possible. Both threshold and maximum steepness of the relation between internal potential and peak tension depend on pulse duration. The relation between the tension-time integral and the stimulus amplitude-duration product was examined. The utility of this relation for excitation-contraction studies is based on the observation that once a depolarizing pulse configuration has elicited maximum tension, further increases in either stimulus duration or amplitude only prolong the contractile response, while the major portion of the relaxation phase after the end of a pulse is exponential, with a time constant that is not significantly affected by either the amplitude or the duration of the pulse. Hence, the area under the tension-response curve provides a measure of the availability to troponin of the calcium released from the sarcoplasmic reticulum in response to membrane depolarization. The results from this work complement those obtained in experiments in which intramembrane charge movements related to contractile activation were studied and those in which intracellular Ca++ transients were measured.

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