scholarly journals Length-tension relation in Limulus striated muscle.

1980 ◽  
Vol 87 (1) ◽  
pp. 204-208 ◽  
Author(s):  
B Walcott ◽  
M M Dewey
Keyword(s):  
Horseshoe Crab ◽  
Sarcomere Length ◽  
Striated Muscle ◽  
Laser Diffraction ◽  
Frog Muscle ◽  
Constant Length ◽  
Maximum Tension ◽  
Thick Filaments ◽  
Average Maximum ◽  
Length Range

Laser diffraction techniques coupled with simultaneous tension measurements were used to determine the length-tension relation in intact, small (0.5-mm thick, 10-mm wide, 20-25-mm long) bundles of a Limulus (horseshoe crab) striated muscle, the telson levator muscle. This muscle differs from the model vertebrate systems in that the thick filaments are not of a constant length, but shorten from 4.9 to approximately 2.0 micrometers as the sarcomeres shorten from 7 to 3 micrometers. In the Limulus muscle, the length-tension relation plateaued to an average maximum tension of 0.34 N/mm2 at a sarcomere length of 6.5 micrometers (Lo) to 8.0 micrometers. In the sarcomere length range from 3.8 to 12.5 micrometers, the muscle developed 50% or more of the maximum tension. When the sarcomere lengths are normalized (expressed as L/Lo) and the Limulus data are compared to those from frog muscle, it is apparent that Limulus muscle develops tension over a relatively greater range of sarcomere lengths.

scholarly journals Series Elasticity in Frog Muscle as Revealed by Optical Diffraction

1982 ◽  
Vol 35 (6) ◽  
pp. 617
Author(s):  
Julian A Barden ◽  
Peter Mason
Keyword(s):  
Sarcomere Length ◽  
Striated Muscle ◽  
Small Population ◽  
Frog Muscle ◽  
Optical Diffraction ◽  
Muscle Fibres ◽  
Series Elasticity ◽  
Thick Filaments ◽  
Cross Bridges ◽  
Made In

Using an optical diffraction technique, the series elasticity of frog striated muscle fibres was investigated. One source of series elasticity was located in the cross-bridges during the application of either quick stretches or releases of muscle fibres. Evidence is presented here for a second component attributable to a small population of slowly activated sarcomeres. The size of the second component was progressively reduced until it virtually disappeared at a sarcomere length of 3 pm. A third component appears to reside in the thick filaments. Calculation of the elastic energy in the muscle fibres enabled an identification of the source of the energy to be made in terms of the components of the series elasticity. Evidence is presented of a short-range elastic component present in resting fibres.

scholarly journals Changes in thick filament length in Limulus striated muscle.

1977 ◽  
Vol 75 (2) ◽  
pp. 366-380 ◽  
Author(s):  
M M Dewey ◽  
B Walcott ◽  
D E Colflesh ◽  
H Terry ◽  
R J Levine
Keyword(s):  
Horseshoe Crab ◽  
Striated Muscle ◽  
Thick Filament ◽  
Filament Length ◽  
Thin Filaments ◽  
Thick Filaments ◽  
Wide Range ◽  
The Difference

Here we describe the change in thick filament length in striated muscle of Limulus, the horseshoe crab. Long thick filaments (4.0 microns) are isolated from living, unstimulated Limulus striated muscle while those isolated from either electrically or K+-stimulated fibers are significantly shorter (3.1 microns) (P less than 0.001). Filaments isolated from muscle glycerinated at long sarcomere lengths are long (4.4 microns) while those isolated from muscle glycerinated at short sarcomere lengths are short (2.9 microns) and the difference is significant (P less than 0.001). Thin filaments are 2.4 microns in length. The shortening of thick filaments is related to the wide range of sarcomere lengths exhibited by Limulus telson striated muscle.

scholarly journals Elastic behavior of connectin filaments during thick filament movement in activated skeletal muscle.

1989 ◽  
Vol 109 (5) ◽  
pp. 2169-2176 ◽  
Author(s):  
R Horowits ◽  
K Maruyama ◽  
R J Podolsky
Keyword(s):  
Skeletal Muscle ◽  
Calcium Ions ◽  
Striated Muscle ◽  
Muscle Protein ◽  
Thick Filament ◽  
Elastic Behavior ◽  
Constant Length ◽  
Thick Filaments ◽  
Band Spacing ◽  
Antibody Label

Connectin (also called titin) is a huge, striated muscle protein that binds to thick filaments and links them to the Z-disc. Using an mAb that binds to connectin in the I-band region of the molecule, we studied the behavior of connectin in both relaxed and activated skinned rabbit psoas fibers by immunoelectron microscopy. In relaxed fibers, antibody binding is visualized as two extra striations per sarcomere arranged symmetrically about the M-line. These striations move away from both the nearest Z-disc and the thick filaments when the sarcomere is stretched, confirming the elastic behavior of connectin within the I-band of relaxed sarcomeres as previously observed by several investigators. When the fiber is activated, thick filaments in sarcomeres shorter than 2.8 microns tend to move from the center to the side of the sarcomere. This translocation of thick filaments within the sarcomere is accompanied by movement of the antibody label in the same direction. In that half-sarcomere in which the thick filaments move away from the Z-disc, the spacings between the Z-disc and the antibody and between the antibody and the thick filaments both increase. Conversely, on the side of the sarcomere in which the thick filaments move nearer to the Z-line, these spacings decrease. Regardless of whether I-band spacing is varied by stretch of a relaxed sarcomere or by active sliding of thick filaments within a sarcomere of constant length, the spacings between the Z-line and the antibody and between the antibody and the thick filaments increase with I-band length identically. These results indicate that the connectin filaments remain bound to the thick filaments in active fibers, and that the elastic properties of connectin are unaltered by calcium ions and cross-bridge activity.

The site and state of myosin in intestinal smooth muscle

1973 ◽  
Vol 265 (867) ◽  
pp. 219-222 ◽  
Keyword(s):  
Smooth Muscle ◽  
Cross Sections ◽  
Striated Muscle ◽  
Mechanical Tension ◽  
Constant Length ◽  
Substantial Modification ◽  
Thick Filaments ◽  
Myosin Filaments ◽  
Resting Muscle ◽  
Longitudinal Layer

The longitudinal layer of the guinea-pig ileum represents a highly advantageous specimen for the study of vertebrate smooth muscle structure. In this muscle we regularly observed thick filaments, consisting presumably of myosin, in longitudinal as well as in cross-sections, if the samples were fixed at constant length, i.e. standing under mechanical tension. Thick filaments were regularly present also in muscles relaxed by atropine. On the other hand, thick filaments were absent in many cases in slack muscles in K+ contracture. As a consequence, we regard myosin filaments as regular constituents of smooth muscle, independently of the functional state. Their absence in electronmicrographs taken from slack muscles seems an artefact due to processing. We observed the same artefact in bee-wing muscle, i.e. in a striated muscle, too. This fact indicates the importance of mechanical tension and polymer crystallization in the survival of myosin filaments. On the basis of a recent work of Ladik, Biczó and Garamvölgyi we discuss how tension may be exerted on the myosin filaments of the resting muscle. Anyway, the sliding model seems valid also for vertebrate smooth muscle, without any substantial modification.

Abstract P315: Shortening The Thick Filament By Partial Deletion Of Titin’S C-zone Alters Cardiac Function By Reducing The Operating Sarcomere Length Range Of The Heart.

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Mei Methawasin ◽  
Gerrie P Farman ◽  
Shawtarohgn Granzier-Nakajima ◽  
Joshua G Strom ◽  
John E Smith ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Sarcomere Length ◽  
Dynamic Stiffness ◽  
Thick Filament ◽  
Contractile Dysfunction ◽  
Wall Region ◽  
Time Varying ◽  
Thick Filaments ◽  
Length Range ◽  
Cross Bridges

Titin’s C-zone is the inextensible part of titin that binds along the thick filament at its cMyBP-C -containing region. Previously it was shown that deletion of titin’s super-repeats C1 and C2 ( Ttn ΔC1-2 mouse model) results in shorter thick filaments and contractile dysfunction, but LV chamber stiffness is normal. Here we studied the contraction-relaxation kinetics from the time-varying elastance of the left ventricle (LV) and from cellular work loops of intact loaded cardiac myocytes. Ca 2+ transients were also measured as well as crossbridge cycling kinetics and Ca 2+ sensitivity of force. It was found that intact cardiomyocytes of Ttn ΔC1-2 mice exhibit systolic dysfunction and impaired relaxation. The time-varying elastance of the LV chamber showed that the kinetics of LV activation are normal but that relaxation is slower in Ttn ΔC1-2 mice. The slowed relaxation was, in part, attributable to an increased myofilament Ca 2+ sensitivity and slower early Ca 2+ reuptake. Dynamic stiffness at the myofilament level showed that cross-bridge kinetics are normal, but that the number of force-generating cross-bridges is reduced. In vivo sarcomere length (SL) measurements in the mid-wall region of the LV revealed that the operating SL range is shifted in Ttn ΔC1-2 mice towards shorter lengths. This normalizes the apparent cell and LV chamber stiffness but reduces the number of force generating cross-bridges due to suboptimal thin and thick filament overlap. Thus the contractile dysfunction in Ttn ΔC1-2 mice is not only due to shorter thick filaments but also to a reduced operating sarcomere length range. Overall these results reveal that for normal cardiac function, thick filament length regulation by titin’s C-zone is critical.

Caffeine suppresses length dependency of Ca2+ sensitivity of skinned striated muscle

1988 ◽  
Vol 254 (4) ◽  
pp. C491-C497 ◽  
Author(s):  
E. L. de Beer ◽  
R. L. Grundeman ◽  
A. J. Wilhelm ◽  
C. J. Caljouw ◽  
D. Klepper ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Striated Muscle ◽  
Laser Diffraction ◽  
Caffeine Concentration ◽  
Sensitivity Functions ◽  
Freeze Dried ◽  
Sensitivity Curves ◽  
Exact Position ◽  
High Concentrations

Freeze-dried skinned cardiac and skeletal muscle preparations of the rabbit were immersed in Ca2+-containing solutions with different concentrations of caffeine. The relation between the negative logarithm of the Ca2+ concentration (pCa) and normalized developed force was studied. The exact position of these Ca2+-sensitivity functions proved to be dependent on both the sarcomere length (monitored by means of laser diffraction) and caffeine concentration. High concentrations of caffeine induce a reversible fall in tension, particularly at low binding site saturation (low pCa) and long sarcomere lengths. At a concentration of 10 mM caffeine, the sarcomere length dependency of the Ca2+-sensitivity curves is markedly reduced for the rising part of the curve. Only the depressive effect of caffeine at high pCa remains. A possible mechanism of caffeine action is discussed.

X-ray diffraction studies on striated and smooth muscles

1964 ◽  
Vol 160 (981) ◽  
pp. 467-472 ◽  
Keyword(s):  
Actin Filaments ◽  
Sarcomere Length ◽  
Striated Muscle ◽  
Hexagonal Lattice ◽  
Smooth Muscles ◽  
Frog Muscle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Forces ◽  
Resting Muscle

It is appropriate to start this contribution with a tribute to the pioneer small-angle X-ray studies of H. E. Huxley (1953) on living, resting, striated muscle, reported at another discussion meeting of this Society. These studies led to the prediction of many features of the sliding-filament model, and were ahead of their time in technique, as is evident, since it was nearly ten years before any other similar papers were published. 1. The filament lattice of striated muscle The work of Elliott, Lowy & Worthington (1963) on the filament lattice of striated muscle has shown that for both living, resting, muscle and glycerol- extracted muscle the relative intensity of the equatorial reflexions of the hexagonal lattice depends in the same way on sarcomere length. For long sarcomeres the intensity of the (1, 0) reflexion is greater than that of the (1, 1) reflexion, for short sarcomeres the reverse is true. The explanation offered was that the actin filaments contribute to the equatorial pattern only when stabilized by inter-molecular forces within the hexagonal myosin lattice and that they (the actin filaments) are comparatively disordered in the I -band. The actin contribution is in phase for the (1, 1) reflexion and out of phase for the (1, 0), so that, as the actin filaments slide in and the actin contribution increases, the (1, 0) becomes progressively weaker, and the (1, 1) progressively stronger. Calculations on this basis agreed well with the observed effect. It was found that the sarcomere length at which the two reflexions had equal intensity was greater for mammalian than for frog muscle. From this fact it was predicted that the actin filaments in mammalian muscle should be about 0.3 μm longer than in frog muscle; Miss Sally Page has now observed such a difference directly (Page & Huxley 1963).

Introductory Remarks

1980 ◽  
Vol 38 ◽  
pp. 598-599
Author(s):  
H. Mohri
Keyword(s):  
Muscle Contraction ◽  
Experimental Evidence ◽  
Sea Urchin ◽  
Constant Length ◽  
Thin Filaments ◽  
Bridge Formation ◽  
Thick Filaments ◽  
Sliding Mechanism ◽  
Radial Spokes ◽  
Cilia And Flagella

In 1959, Afzelius observed the presence of two rows of arms projecting from each outer doublet microtubule of the so-called 9 + 2 pattern of cilia and flagella, and suggested a possibility that the outer doublet microtubules slide with respect to each other with the aid of these arms during ciliary and flagellar movement. The identification of the arms as an ATPase, dynein, by Gibbons (1963)strengthened this hypothesis, since the ATPase-bearing heads of myosin molecules projecting from the thick filaments pull the thin filaments by cross-bridge formation during muscle contraction. The first experimental evidence for the sliding mechanism in cilia and flagella was obtained by examining the tip patterns of molluscan gill cilia by Satir (1965) who observed constant length of the microtubules during ciliary bending. Further evidence for the sliding-tubule mechanism was given by Summers and Gibbons (1971), using trypsin-treated axonemal fragments of sea urchin spermatozoa. Upon the addition of ATP, the outer doublets telescoped out from these fragments and the total length reached up to seven or more times that of the original fragment. Thus, the arms on a certain doublet microtubule can walk along the adjacent doublet when the doublet microtubules are disconnected by digestion of the interdoublet links which connect them with each other, or the radial spokes which connect them with the central pair-central sheath complex as illustrated in Fig. 1. On the basis of these pioneer works, the sliding-tubule mechanism has been established as one of the basic mechanisms for ciliary and flagellar movement.

Psoas Muscle Architectural Design, In Vivo Sarcomere Length Range, and Passive Tensile Properties Support Its Role as a Lumbar Spine Stabilizer

Spine ◽  
2011 ◽  
Vol 36 (26) ◽  
pp. E1666-E1674 ◽  
Author(s):  
Gilad J. Regev ◽  
Choll W. Kim ◽  
Akihito Tomiya ◽  
Yu Po Lee ◽  
Hossein Ghofrani ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Tensile Properties ◽  
Architectural Design ◽  
Sarcomere Length ◽  
Psoas Muscle ◽  
Length Range
Sign in / Sign up

Export Citation Format

Share Document