scholarly journals VARIATION OF SARCOMERE LENGTH, SARCOMERE NUMBER AND TETANIC TENSION OF SKELETAL MUSCLE DURING POSTNATAL GROWTH IN MICE

1988 ◽  
Vol 37 (1) ◽  
pp. 46-50 ◽  
Author(s):  
NORIKATSU KASUGA ◽  
MASARU KATO ◽  
KAZUKO KANAMARU
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Postnatal Growth ◽  
Tetanic Tension ◽  
Sarcomere Number

Sarcomere length non-uniformity in relation to tetanic responses of stretched skeletal muscle fibres

1978 ◽  
Vol 200 (1138) ◽  
pp. 109-116 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Thin Filament ◽  
Sarcomere Length ◽  
Muscle Fibres ◽  
Plateau Region ◽  
Constant Length ◽  
Tension Response ◽  
Force Velocity ◽  
Skeletal Muscle Fibres ◽  
Tetanic Tension

At sarcomere lengths above the plateau region of the length-tension diagram, it has been found that isometric tetanic tension is proportional to the amount of thick and thin filament overlap. This finding has been questioned recently and is reinvestigated here. Central segments of single frog skeletal muscle fibres were held at constant length during contractions at various sarcomere lengths above those associated with the plateau region. Tension records showed little or no creep, and the tetanic tensions measured at 0 and 20°C were inversely proportional to sarcomere length. These results extend and substantiate earlier findings. In contrast, when a stretched fibre had only its ends fixed during a tetanus, a different tension response was observed. The tension rise was initially very rapid but soon slowed to a gradual upward creep as stimulation was continued. This was followed by a tension decline. These tension phases were correlated with large decreases in sarcomere length at the fibre ends, while sarcomeres in the middle were extended a small amount. This tetanic tension response can be explained using the sarcomere length-tension relation and the force-velocity properties of muscle. These results strongly support the sliding filament, cross-bridge theory of muscle contraction.

Effects of Skeletal Muscle Sarcomere Length onin VivoCapillary Distensibility

1999 ◽  
Vol 57 (2) ◽  
pp. 144-152 ◽  
Author(s):  
Casey A. Kindig ◽  
David C. Poole
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length

Effect of sarcomere length on total capillary length in skeletal muscle: In vivo evidence for longitudinal stretching of capillaries

1990 ◽  
Vol 40 (1) ◽  
pp. 63-72 ◽  
Author(s):  
C.G. Ellis ◽  
O. Mathieu-Costello ◽  
R.F. Potter ◽  
I.C. MacDonald ◽  
A.C. Groom
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Capillary Length

Sarcomere strain and heterogeneity correlate with injury to frog skeletal muscle fiber bundles

2004 ◽  
Vol 97 (5) ◽  
pp. 1803-1813 ◽  
Author(s):  
Tina J. Patel ◽  
Ronnie Das ◽  
Jan Fridén ◽  
Gordon J. Lutz ◽  
Richard L. Lieber
Keyword(s):  
Line Width ◽  
Muscle Fiber ◽  
Muscle Activation ◽  
Sarcomere Length ◽  
Eccentric Contraction ◽  
Fiber Bundles ◽  
Lower Yield ◽  
Bathing Medium ◽  
Average Maximum ◽  
Tetanic Tension

Sarcomere length and first-order diffraction line width were measured by laser diffraction during elongation of activated frog tibialis anterior muscle fiber bundles (i.e., eccentric contraction) at nominal fiber strains of 10, 25, or 35% ( n = 18) for 10 successive contractions. Tetanic tension, measured just before each eccentric contraction, differed significantly among strain groups and changed dramatically during the 10-contraction treatment ( P < 0.01). Average maximum tetanic tension for the three groups measured before any treatment was 203.7 ± 6.8 kN/m2, but after the 10-eccentric contraction sequence decreased to 180.3 ± 3.8, 125.1 ± 7.8, and 78.3 ± 5.1 kN/m2 for the 10, 25, and 35% strain groups, respectively ( P < 0.0001). Addition of 10 mM caffeine to the bathing medium decreased the loss of tetanic tension in the 10% strain group but had only a minimal effect on either the 25 or 35% strain groups. Diffraction pattern line width, a measure of sarcomere length heterogeneity, increased significantly with muscle activation and then continued to increase with successive stretches of the activated muscle. Line width increase after each stretch was significantly correlated with the lower yield tension of the successive contractile record. These data demonstrate a direct association and, perhaps, a causal relationship between sarcomere strain and fiber bundle injury. They also demonstrate that muscle injury is accompanied by a progressive increase in sarcomere length heterogeneity, yielding lower yield tension as injury progresses.

scholarly journals What makes skeletal muscle striated? Discoveries in the endosarcomeric and exosarcomeric cytoskeleton

2018 ◽  
Vol 42 (4) ◽  
pp. 672-684 ◽  
Author(s):  
Jack A. Rall
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Intermediate Filament ◽  
Sarcomere Length ◽  
Thick Filament ◽  
Skeletal Muscle Fiber ◽  
Elastic Behavior ◽  
Filament Length ◽  
Iconic Images ◽  
Elastic Protein

One of the most iconic images in biology is the cross-striated appearance of a skeletal muscle fiber. The repeating band pattern shows that all of the sarcomeres are the same length. All of the A bands are the same length and are located in the middle of the sarcomeres. Furthermore, all of the myofibrils are transversely aligned across the muscle fiber. It has been known for 300 yr that skeletal muscle is striated, but only in the last 40 yr has a molecular understanding of the striations emerged. In the 1950s it was discovered that the extraction of myosin from myofibrils abolished the A bands, and the myofibrils were no longer striated. With the further extraction of actin, only the Z disks remained. Strangely, the sarcomere length did not change, and these “ghost” myofibrils still exhibited elastic behavior. The breakthrough came in the 1970s with the discovery of the gigantic protein titin. Titin, an elastic protein ~1 µm in length, runs from the Z disk to the middle of the A band and ensures that each sarcomere is the same length. Titin anchors the A band in the middle of the sarcomere and may determine thick-filament length and thus A-band length. In the 1970s it was proposed that the intermediate filament desmin, which surrounds the Z disks, connects adjacent myofibrils, resulting in the striated appearance of a skeletal muscle fiber.

Sarcomere length operating range of vertebrate muscles during movement

2001 ◽  
Vol 204 (9) ◽  
pp. 1529-1536 ◽  
Author(s):  
T.J. Burkholder ◽  
R.L. Lieber
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Narrow Range ◽  
Analytical Techniques ◽  
Operating Range ◽  
Physiological Importance ◽  
Rigor State ◽  
Secondary Purpose ◽  
Length Measurements ◽  
Length Changes

The force generated by skeletal muscle varies with sarcomere length and velocity. An understanding of the sarcomere length changes that occur during movement provides insights into the physiological importance of this relationship and may provide insights into the design of certain muscle/joint combinations. The purpose of this review is to summarize and analyze the available literature regarding published sarcomere length operating ranges reported for various species. Our secondary purpose is to apply analytical techniques to determine whether generalizations can be made regarding the “normal” sarcomere length operating range of skeletal muscle. The analysis suggests that many muscles operate over a narrow range of sarcomere lengths, covering 94+/−13 % of optimal sarcomere length. Sarcomere length measurements are found to be systematically influenced by the rigor state and methods used to make these measurements.

scholarly journals Effects of myofiber isolation technique on sarcolemma biomechanics

BioTechniques ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 388-391
Author(s):  
Karla P Garcia-Pelagio ◽  
Stephen JP Pratt ◽  
Richard M Lovering
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Sarcomere Length ◽  
Biomechanical Properties ◽  
Isolation Technique ◽  
Enzymatic Dissociation ◽  
Flexor Digitorum Brevis ◽  
Flexor Digitorum ◽  
Biomechanical Measurements

Isolated myofibers are commonly used to understand the function of skeletal muscle in vivo. This can involve single isolated myofibers obtained from dissection or from enzymatic dissociation. Isolation via dissection allows control of sarcomere length and preserves tendon attachment but is labor-intensive, time-consuming and yields few viable myofibers. In contrast, enzymatic dissociation is fast and facile, produces hundreds of myofibers, and more importantly reduces the number of muscles/animals needed for studies. Biomechanical properties of the sarcolemma have been studied using myofibers from the extensor digitorum longus, but this has been limited to dissected myofibers, making data collection slow and difficult. We have modified this tool to perform biomechanical measurements of the sarcolemma in dissociated myofibers from the flexor digitorum brevis.

scholarly journals Discrete sarcomere length distribution in skeletal muscle

1982 ◽  
Vol 37 (2) ◽  
pp. 489-492 ◽  
Author(s):  
T. Tameyasu ◽  
N. Ishide ◽  
G.H. Pollack
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Length Distribution
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