Comparative contractile dynamics of calling and locomotor muscles in three hylid frogs.

1995 ◽  
Vol 198 (7) ◽  
pp. 1527-1538 ◽  
Author(s):  
D McLister ◽  
E D Stevens ◽  
J P Bogart
Keyword(s):  
Relaxation Time ◽  
Isometric Tension ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Shortening Velocity ◽  
Call Production ◽  
Mating Call ◽  
Locomotor Muscles ◽  
Force Velocity ◽  
Isometric Twitch

Isometric twitch and tetanus parameters, force-velocity curves, maximum shortening velocity (Vmax) and percentage relaxation between stimuli (%R) across a range of stimulus frequencies were determined for a muscle used during call production (the tensor chordarum) and a locomotor muscle (the sartorius) for three species of hylid frogs, Hyla chrysoscelis, H. versicolor and H. cinerea. The call of H. chrysoscelis has a note repetition rate (NRR) approximately twice as fast as the call of H. versicolor (28.3, 42.5 and 56.8 notes s-1 for H. chrysoscelis and 14.8, 21.1 and 27.4 notes s-1 for H. versicolor at 15, 20 and 25 degrees C, respectively). Hyla cinerea calls at a very slow NRR (Approximately 3 notes s-1 at 25 degrees C). Hyla versicolor evolved from H. chrysoscelis via autopolyploidy, so the mating call of H. chrysoscelis is presumably the ancestral mating call of H. versicolor. For the tensor chordarum of H. chrysoscelis, H. versicolor and H. cinerea at 25 degrees C, mean twitch duration (19.2, 30.0 and 52.9 ms, respectively), maximum isometric tension (P0; 55.0, 94.4 and 180.5 kN m-2, respectively), tetanic half-relaxation time (17.2, 28.7 and 60.6 ms, respectively) and Vmax (4.7, 5.2 and 2.1 lengths s-1, respectively) differed significantly (P < 0.05) among all three species. The average time of tetanic contraction to half-P0 did not differ significantly between H. chrysoscelis (14.5 ms) and H. versicolor (15.8 ms) but was significantly longer for H. cinerea (52.6 ms). At 25 degrees C, Vmax differed significantly among the sartorius muscles of H. chrysoscelis, H. versicolor and H. cinerea (5.2, 7.0 and 9.8 lengths s-1, respectively) but mean twitch duration (29.5, 32.2 and 38.7 ms, respectively), P0 (252.2, 240.7 and 285.1 kN m-2, respectively) and tetanic half-relaxation time (56.3, 59.5 and 60.7 ms, respectively) did not differ significantly. The average time of contraction to half-P0 did not differ significantly between H. chrysoscelis (23.7 ms) and H. versicolor (22.9 ms) but was significantly shorter for H. cinerea (15.6 ms). The only consistent contractile differences found in this study between the calling muscle and locomotor muscle of H. chrysoscelis, H. versicolor and H. cinerea were that the calling muscles generated less tension and their force-velocity relationship was much more linear. These differences may be attributable to ultrastructural differences between calling and locomotor muscles.(ABSTRACT TRUNCATED AT 400 WORDS)

Force-Velocity Relationships of a Locust Flight Muscle at Different Times During a Twitch Contraction

1991 ◽  
Vol 159 (1) ◽  
pp. 65-87 ◽  
Author(s):  
JEAN G. MALAMUD ◽  
ROBERT K. JOSEPHSON
Keyword(s):  
Flight Muscle ◽  
Isometric Force ◽  
Velocity Curve ◽  
Shortening Velocity ◽  
Single Twitch ◽  
Emory University ◽  
Generating Capacity ◽  
Force Velocity ◽  
Maximum Isometric Force ◽  
Isometric Twitch

The force-velocity relationships during isotonic shortening were determined for the metathoracic second tergocoxal muscle of the locust Schistocerca americana (Drury). This muscle is a synchronous flight muscle. During the plateau of a tetanic contraction, the maximum shortening velocity (Vmax) determined from the force-velocity curve was 5.2 muscle lengths s−1 (25°C) and the curvature (a/Po) was 0.62. The maximum isometric force (P0) was 36.3 N cm−2. Early in a twitch (at times shorter than the isometric twitch rise time) the values for Vmax and curvature were similar to those during the tetanic plateau, but the curves at different times during the twitch intercepted the force axis at values less than P0. Later in the twitch, Vmax declined. A variable termed degree of activation (DA) is developed as a measure of the force-generating capacity of a muscle when this may be time-varying, as throughout most of a twitch. DA is determined from the shortening velocity at an intermediate load and is the predicted intercept of the force-velocity curve with the force axis relative to the tetanic intercept. In the locust muscle, DA rose to a maximum in 2–3 ms after the end of the latent period. DA reached 80° of the tetanic value during a single twitch; during the second twitch of a pair, the peak DA reached approximately the tetanic value. After a brief plateau, DA declined approximately exponentially. The time constant of DA decay was about 14 ms. Note: Present address: Department of Physiology, Emory University, Atlanta, GA30322, USA.

Endocardium modulates myocardial inotropic response to 5-hydroxytryptamine

1989 ◽  
Vol 257 (6) ◽  
pp. H1790-H1797 ◽  
Author(s):  
A. M. Shah ◽  
L. J. Andries ◽  
A. L. Meulemans ◽  
D. L. Brutsaert
Keyword(s):  
Relaxation Time ◽  
Heart Muscle ◽  
Isolated Heart ◽  
Inhibitory Effect ◽  
Papillary Muscles ◽  
Inotropic Response ◽  
Shortening Velocity ◽  
Isometric Twitch ◽  
Triton X ◽  
Contractile Performance

The endocardium modulates contractile performance of subjacent myocardium in isolated heart muscle. We investigated the effects of 5-hydroxytryptamine (5-HT, 0.01-30 microM) on isolated cat papillary muscles with or without intact endocardium (+E or -E, respectively). Selective endocardial damage by 1-s immersion in 1% Triton X-100 caused reduction in half-isometric relaxation time (RT1/2) and isometric twitch tension (TT), but not maximum unloaded shortening velocity (Vmax). 5-HT caused reduction in RT1/2 in endocardium-intact but an increase in endocardium-damaged preparations (at 30 microM: -12.1 +/- 1.8%, +E; +5.2 +/- 1.5%, -E). Mean percent increases in TT were greater in endocardium-damaged muscles (at 30 microM: 37.3 +/- 8.6%, +E; 107.3 +/- 19.5%, -E). In the presence of ketanserin (1 microM), 5-HT reduced RT1/2 in endocardium-intact (at 30 microM: -11.9 +/- 1.3%) but not endocardium-damaged muscles (except slightly at 30 microM) and increased TT at 30 microM by 28.7 +/- 4.9% (+E) and 48.9 +/- 15.6% (-E). In the presence of propranolol (1 microM), 5-HT increased RT1/2 (+E and -E) while increasing TT by 23.3 +/- 7.8% (+E) and 43.5 +/- 2.5% (-E). Endocardium did not influence changes in Vmax. Ketanserin (1 microM), but not propranolol (1 microM), markedly diminished endocardial damage induced by 5-HT (greater than or equal to 10 microM). These results suggest a 5-HT-induced endocardium-mediated "inhibitory" effect (causing earlier isometric relaxation) that is not blocked by ketanserin.

Influence of myosin isoforms on contractile properties of intact muscle fibers from Rana pipiens

2002 ◽  
Vol 282 (4) ◽  
pp. C835-C844 ◽  
Author(s):  
Gordon J. Lutz ◽  
Shashank R. Sirsi ◽  
Sarah A. Shapard-Palmer ◽  
Shannon N. Bremner ◽  
Richard L. Lieber
Keyword(s):  
Myosin Light Chain ◽  
Rana Pipiens ◽  
Isometric Tension ◽  
Myosin Isoforms ◽  
Shortening Velocity ◽  
Cross Sectional ◽  
Sds Page ◽  
Intact Muscle ◽  
Force Velocity ◽  
Fast Twitch

The myosin heavy chain (MHC) and myosin light chain (MLC) isoforms in skeletal muscle of Rana pipiens have been well characterized. We measured the force-velocity (F- V) properties of single intact fast-twitch fibers from R. pipiens that contained MHC types 1 or 2 (MHC1 or MHC2) or coexpressed MHC1 and MHC2 isoforms. Velocities were measured between two surface markers that spanned most of the fiber length. MHC and MLC isoform content was quantified after mechanics analysis by SDS-PAGE. Maximal shortening velocity ( V max) and velocity at half-maximal tension ( V P 50) increased with percentage of MHC1 (%MHC1). Maximal specific tension (Po/CSA, where Po is isometric tension and CSA is fiber cross-sectional area) and maximal mechanical power ( W max) also increased with %MHC1. MHC concentration was not significantly correlated with %MHC1, indicating that the influence of %MHC1 on Po/CSA and W max was due to intrinsic differences between MHC isoforms and not to concentration. The MLC3-to-MLC1 ratio was not significantly correlated with V max, V P 50, Po/CSA, or W max. These data demonstrate the powerful relationship between MHC isoforms and F- V properties of the two most common R. pipiensfiber types.

Power output of sound-producing muscles in the tree frogs Hyla versicolor and Hyla chrysoscelis

1999 ◽  
Vol 202 (22) ◽  
pp. 3225-3237 ◽  
Author(s):  
M. Girgenrath ◽  
R.L. Marsh
Keyword(s):  
Power Output ◽  
Maximum Power ◽  
Trunk Muscles ◽  
Total Power ◽  
Hyla Versicolor ◽  
Tree Frog ◽  
Hyla Chrysoscelis ◽  
Force Velocity ◽  
External Oblique

Sound-producing muscles provide the opportunity of studying the limits of power production at high contractile frequencies. We used the work loop technique to determine the power available from the external oblique muscles in two related species of North American gray tree frog, Hyla chrysoscelis and Hyla versicolor. These trunk muscles contract cyclically, powering high-intensity sound production in anuran amphibians. The external oblique muscles in H. chrysoscelis have an in vivo operating frequency of 40–55 Hz at 20–25 degrees C, whereas in H. versicolor these muscles contract with a frequency of 20–25 Hz at these temperatures. In vivo investigations have shown that these muscles use an asymmetrical sawtooth length trajectory (with a longer shortening phase compared with the lengthening phase) during natural cycles. To study the influence of this particular length trajectory on power output, we subjected the muscles to both sinusoidal and sawtooth length trajectories. In both species, the sawtooth trajectory yielded a significantly higher power output than the sinusoidal length pattern. The maximum power output during sawtooth cycles was similar in both species (54 W kg(−)(1) in H. chrysoscelis and 58 W kg(−)(1) in H. versicolor). These values are impressive, particularly at the operating frequencies and temperatures of the muscle. The sinusoidal length trajectory yielded only 60 % of the total power output compared with the sawtooth trajectory (34 W kg(−)(1) for H. chrysoscelis and 36 W kg(−)(1) for H. versicolor). The optimum cycle frequencies maximizing the power output using a sawtooth length pattern were approximately 44 Hz for H. chrysoscelis and 21 Hz for H. versicolor. These frequencies are close to those used by the two species during calling. Operating at higher frequencies, H. chrysoscelis maximized power at a strain amplitude of only 8 % compared with a value of 12 % in H. versicolor. These strains match those used in vivo during calling. The stimulus timing observed in vivo during calling was also similar to that yielding maximum power at optimal frequency in both species (6 ms and 8 ms before the start of shortening in H. chrysoscelis and H. versicolor, respectively). As expected, twitch duration in H. chrysoscelis is much shorter than that in H. versicolor (23 ms and 37 ms, respectively). There was a less remarkable difference between their maximum shortening velocities (V(max)) of 13.6 L(0)s(−)(1) in H. chrysoscelis and 11.1 L(0)s(−)(1) in H. versicolor, where L(0) is muscle length. The force-velocity curves are very flat, which increases power output. At the myofibrillar level, the flat force-velocity curves more than compensate for the lower peak isometric force found in these muscles. The data presented here emphasize the importance of incorporating in vivo variables in designing in vitro studies.

Contraction of glycerinated rabbit slow-twitch muscle fibers as a function of MgATP concentration

1992 ◽  
Vol 262 (4) ◽  
pp. C1039-C1046 ◽  
Author(s):  
E. Pate ◽  
M. Lin ◽  
K. Franks-Skiba ◽  
R. Cooke
Keyword(s):  
Psoas Muscle ◽  
Isometric Tension ◽  
Maximal Velocity ◽  
Shortening Velocity ◽  
A Value ◽  
Semimembranosus Muscle ◽  
Slow Twitch Muscle ◽  
Force Velocity ◽  
Slow Twitch ◽  
Fast Twitch

We have measured the isometric tension and force-velocity relationships of glycerinated rabbit slow-twitch semimembranosus muscle as a function of MgATP concentration ([MgATP]) and have compared the results with those obtained previously from fast-twitch psoas muscle. We find that isometric tension decreases as [MgATP] increases. The magnitude of the decrease is not as great as observed in psoas. Maximum shortening velocity (Vmax) exhibits classical Michaelian saturation behavior with respect to [MgATP] with a Michaelis constant (Km) for half-maximal velocity of 18 microM and a value at saturating [MgATP] of 0.6 muscle lengths/s. Similar values were observed in fibers from soleus, another slow-twitch muscle. The corresponding values in rabbit psoas muscle are 150 microM and 1.6 lengths/s. Compared with psoas, in semimembranosus muscle Km decreases by a factor of approximately 10, whereas Vmax decreases by about a factor of 3. Thus, although in a nonphysiological regime, at low [MgATP], a "fast" muscle actually has a lower shortening velocity than a "slow" muscle.

Revisiting the evolution of the North American tetraploid treefrog (Hyla versicolor)

Genome ◽  
2020 ◽  
Vol 63 (11) ◽  
pp. 547-560 ◽  
Author(s):  
James P. Bogart ◽  
Patrick Burgess ◽  
Jinzhong Fu
Keyword(s):  
Diploid Species ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Gene Exchange ◽  
Tetraploid Species ◽  
Sympatric Populations ◽  
Female Progeny ◽  
The North ◽  
Mating Call ◽  
Mitochondrial Cytochrome B

Hyla chrysoscelis and H. versicolor are common treefrogs in eastern North America and are a cryptic diploid–tetraploid species pair. They are morphologically identical but H. versicolor is a tetraploid. They can be identified acoustically by the male’s advertisement mating call, which has a pulse repetition rate that has twice as many pulses per second in the diploid species, H. chrysoscelis. We used isozymes, microsatellite DNA alleles, and mitochondrial cytochrome b sequences to test the hypothesis that gene exchange occurs between the diploid and tetraploid species in sympatric populations. Each method provided results that are best explained by occasional hybridization of female H. versicolor and male H. chrysoscelis. We propose that H. versicolor first arose from an autotriploid H. chrysoscelis female that produced unreduced triploid eggs. After H. versicolor became established, genes could be passed from H. chrysoscelis to H. versicolor in sympatric populations when these species hybridize. Their F1 female progeny produce unreduced triploid eggs that are fertilized by haploid H. chrysoscelis sperm to reconstitute H. versicolor. Genes can be passed from diploid H. chrysoscelis to tetraploid H. versicolor in sympatric populations.

Contractile properties of cat skeletal muscle after repetitive stimulation

1988 ◽  
Vol 64 (2) ◽  
pp. 502-510 ◽  
Author(s):  
D. D. Hatcher ◽  
A. R. Luff
Keyword(s):  
Recovery Period ◽  
Isometric Tension ◽  
Maximum Speed ◽  
Time To Peak ◽  
Force Velocity ◽  
Cross Bridges ◽  
Isometric Twitch ◽  
Flexor Digitorum ◽  
Fast Twitch ◽  
Speed Of Shortening

The isometric and force-velocity properties of the fast-twitch flexor digitorum longus (FDL) and slow-twitch soleus muscles were investigated immediately after and during recovery from a fatiguing stimulus regime (40 Hz for 330 ms every second for 180 s) in the anesthetized cat. The amplitude of the isometric twitch of FDL was unaffected but in soleus it remained depressed for much of the recovery period. Immediately after stimulation the twitch time to peak of FDL increased to 140% of the control (prefatigue) value and then reverted to control values. The maximum isometric tetanic tension (Po) developed by FDL was reduced to 67% of control values immediately after the stimulus regime, whereas soleus declined to 93% of control. Recovery of maximum force development was achieved after 45 min in FDL and after 15 min in soleus. The maximum speed of shortening of FDL was reduced to 63% of control values immediately after fatigue; despite some recovery within the first 30 min, it remained depressed during the remainder of the recovery period (up to 300 min). Maximum speed of shortening was unaltered in soleus. The a/Po value transiently increased to 176% of control values in FDL immediately after the fatigue regime but promptly returned to control values. Force-velocity properties of soleus were not affected by the stimulus regime. It is concluded that in FDL changes in the maximum speed of shortening and maximum isometric tension as a result of the stimulus regime are attributable to changes in the intrinsic behavior of cross-bridges and the metabolic status of the fibers, particularly in the fast-twitch fatigue-resistant fibers.

scholarly journals The Contractile Properties of a Crab Respiratory Muscle

1987 ◽  
Vol 131 (1) ◽  
pp. 265-287 ◽  
Author(s):  
ROBERT K. JOSEPHSON ◽  
DARRELL R. STOKES
Keyword(s):  
Carcinus Maenas ◽  
Stimulus Frequency ◽  
Muscle Length ◽  
Isometric Tension ◽  
Shortening Velocity ◽  
Force Velocity ◽  
Contraction And Relaxation ◽  
Full Activation ◽  
Stimulus Number

1. Contraction of scaphognathite muscle L2B of the green crab Carcinus maenas is strongly dependent on stimulus number and frequency. Single, supramaximal stimuli evoke little or no tension. When stimulated with shocks in either short bursts (10 stimuli in 0.5s or less) or long bursts (5 s of stimulation), the isometric tension from the muscle increases with increasing stimulus frequency to a maximum at about 150 Hz at 15°C, beyond which tension declines with further increase in stimulus frequency. 2. There can be facilitation of both contraction and relaxation between short bursts of stimuli. Facilitation of contraction is seen as increasing tension on successive bursts of a series, even when the interburst interval is long enough for relaxation to be completed during the interval. Interburst facilitation lasts at least 10 s. Facilitation of relaxation is seen as progressively faster relaxation from burst to burst of a series, and relaxation to lower tension levels when the interburst interval is so short that relaxation is incomplete in the interburst interval. 3. Maximum isometric tension occurs at muscle lengths slightly longer than the longest muscle length reached in vivo. Tension declines rapidly with changes in muscle length away from the optimum length. The maximum isometric tension was about 12 N cm−2. 4. The maximum shortening velocity of a tetanically activated muscle was determined as 1.9 lengthss−1 (Ls−1) by extrapolation of force-velocity curves to zero force and 3.3 Ls−1 by slack test measurements. 5. The scaphognathite muscle would be classified as a slow or tonic muscle on the basis of its requirements for multiple stimulation to reach full activation, and as a moderately fast muscle on the basis of its force-velocity properties.

Contractile, biochemical, and histochemical properties of thyrotoxic rat soleus muscle

1980 ◽  
Vol 238 (1) ◽  
pp. C15-C20 ◽  
Author(s):  
R. H. Fitts ◽  
W. W. Winder ◽  
M. H. Brooke ◽  
K. K. Kaiser ◽  
J. O. Holloszy
Keyword(s):  
Relaxation Time ◽  
Sarcoplasmic Reticulum ◽  
Soleus Muscle ◽  
Biochemical Properties ◽  
Contractile Properties ◽  
Contraction Time ◽  
Shortening Velocity ◽  
Actomyosin Atpase ◽  
Atpase Reaction ◽  
Isometric Twitch

The effects of thyrotoxicosis on the contractile properties of soleus muscle were examined in rats given 3 mg of T4 and 1 mg of T3 per kg of diet for 6–8 wk. Thyrotoxicosis induced significant decreases in isometric twitch contraction time (CT), one-half relaxation time, and peak twitch tension. The Ca2+ uptake activity of the sarcoplasmic reticulum (SR) was increased in the thyrotoxic muscles; this adaptation in the SR provides a possible mechanism for the alterations in isometric contractile properties. Thyrotoxicosis induced a large increase in fibers classified as type 2, on the basis of an alkali-stable histochemical reaction for ATPase, in the soleus. Although this reaction is commonly interpreted as indicating that a muscle is fast, maximum shortening velocity (Vmax) and Mg2+ activated actomyosin ATPase activity were unaffected in the thyrotoxic soleus. Our findings provide evidence that CT and Vmax can vary independently and that the histochemical ATPase reaction may not always reflect the biochemical properties that make myosin fast or slow. actomyosin ATPase; histochemical ATPase reaction; isometric contraction time; maximum shortening velocity; one-half relaxation time; sarcoplasmic reticulum; skeletal muscle Submitted on April 13, 1979 Accepted on August 7, 1979

Relative shortening velocity in locomotor muscles: turkey ankle extensors operate at low V/Vmax

2008 ◽  
Vol 294 (1) ◽  
pp. R200-R210 ◽  
Author(s):  
Annette M. Gabaldón ◽  
Frank E. Nelson ◽  
Thomas J. Roberts
Keyword(s):  
Isometric Force ◽  
Muscle Length ◽  
Shortening Velocity ◽  
Velocity Relationship ◽  
Locomotor Muscles ◽  
Force Velocity ◽  
Wild Turkeys ◽  
Strain Gauge Measurements ◽  
All Speeds ◽  
Level Running

The force-velocity properties of skeletal muscle have an important influence on locomotor performance. All skeletal muscles produce less force the faster they shorten and typically develop maximal power at velocities of ∼30% of maximum shortening velocity (Vmax). We used direct measurements of muscle mechanical function in two ankle extensor muscles of wild turkeys to test the hypothesis that during level running muscles operate at velocities that favor force rather than power. Sonomicrometer measurements of muscle length, tendon strain-gauge measurements of muscle force, and bipolar electromyographs were taken as animals ran over a range of speeds and inclines. These measurements were integrated with previously measured values of muscle Vmax for these muscles to calculate relative shortening velocity (V/Vmax). At all speeds for level running the V/Vmax values of the lateral gastrocnemius and the peroneus longus were low (<0.05), corresponding to the region of the force-velocity relationship where the muscles were capable of producing 90% of peak isometric force but only 35% of peak isotonic power. V/Vmax increased in response to the demand for mechanical power with increases in running incline and decreased to negative values to absorb energy during downhill running. Measurements of integrated electromyograph activity indicated that the volume of muscle required to produce a given force increased from level to uphill running. This observation is consistent with the idea that V/Vmax is an important determinant of locomotor cost because it affects the volume of muscle that must be recruited to support body weight.

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