Measurement of the striations of isolated muscle fibres with the interference microscope

Huxley, Andrew; Niedergerke, R.

doi:10.1113/jphysiol.1958.sp006110

Cited by 89 publications

(55 citation statements)

References 23 publications

(26 reference statements)

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“…It should be noted that the refractive index mismatch ⌬n varies with the sarcomere length [16] consistent with experimental observations [31]. Similar to a previous study [39], we assumed that ⌬n was proportional to the square of the sarcomere length.…”

Section: B Sarcomere Model and Parameterssupporting

confidence: 73%

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Effects of inhomogeneous myofibril morphology on optical diffraction in single muscle fibers

Ranasinghesagara

Yao

2008

J. Opt. Soc. Am. A

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Laser diffraction is commonly used in physiological research that explores single muscle fibers. Although variations in sarcomere morphological properties have often been observed, their effects on laser diffraction have not been studied in detail. In this study, we applied three-dimensional coupled wave theory to a physical sarcomere model to investigate the effects of inhomogeneous morphological profiles in muscle fibers. The simulation results were compared with several those of published experimental studies. Our results indicate that by incorporating various myofibril inhomogeneities such as skew and domain effect in the theoretical model, a variety of observations in single fiber diffraction under different experimental conditions can be reproduced in the simulation.

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Section: B Sarcomere Model and Parameterssupporting

confidence: 73%

“…In our simulation, all sarcomere parameters were chosen based on experimental measurements. From published data [31][32][33][34][35][36][37][38], the typical physiological ranges of several major sarcomere parameters are shown in Table 1 [12,14,16].…”

Section: B Sarcomere Model and Parametersmentioning

confidence: 99%

Effects of inhomogeneous myofibril morphology on optical diffraction in single muscle fibers

Ranasinghesagara

Yao

2008

J. Opt. Soc. Am. A

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“…Therefore, our results do not support the notion, based on earlier radioautographic studies having lower spatial resolution (108,109), that Ca, after leaving the release sites (TC), is accumulated and stored for a relatively long time at "uptake sites" ofthe LSR . Our results suggest that 45 Ca, identified in radioautographs as bound to LSR (108,109), was in fact bound to Ca-binding proteins . The combined results of the analysis ofthe TC and of the LSR are also inconsistent with the interpretation of Ca" flux data that ascribe a relatively small (0.2 mmol/kg wet muscle), fast exchanging (time constant = 2.7 min) component as representing the Ca content of the TC, and a larger (0.54 mmole/kg wet muscle) slowly exchanging (time-constant = 1,244 min) component to the LSR (54).…”

Section: The Composition Of the Cytoplasm And Of The Lsr During Tetanmentioning

confidence: 74%

Calcium release and ionic changes in the sarcoplasmic reticulum of tetanized muscle: an electron-probe study.

Somlyo¹,

González‐Serratos²,

Shuman³

et al. 1981

The Journal of Cell Biology

421

223

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Approximately 60-70% of the total fiber calcium was localized in the terminal cisternae (TC) in resting frog muscle as determined by electron-probe analysis of ultrathin cryosections . During a 1 .2 s tetanus, 59% (69 mmol/kg dry TC) of the calcium content of the TC was released, enough to raise total cytoplasmic calcium concentration by -1 mM . This is equivalent to the concentration of binding sites on the calcium-binding proteins (troponin and parvalbumin) in frog muscle . Calcium release was associated with a significant uptake of magnesium and potassium into the TC, but the amount of calcium released exceeded the total measured cation accumulation by 62 mEq/kg dry weight . It is suggested that most of the charge deficit is apparent, and charge compensation is achieved by movement of protons into the sarcoplasmic reticulum (SR) and/or by the movement of organic co-or counterions not measured by energy dispersive electron-probe analysis . There was no significant change in the sodium or chlorine content of the TIC during tetanus. The unchanged distribution of a permeant anion, chloride, argues against the existence of a large and sustained transSR potential during tetanus, if the chloride permeability of the in situ SR is as high as suggested by measurements on fractionated SR .The calcium content of the longitudinal SR (LSR) during tetanus did not show the LSR to be a major site of calcium storage and delayed return to the TC . The potassium concentration in the LSR was not significantly different from the adjacent cytoplasmic concentration. Analysis of small areas of I-band and large areas, including several sarcomeres, suggested that chloride is anisotropically distributed, with some of it probably bound to myosin . In contrast, the distribution of potassium in the fiber cytoplasm followed the water distribution . The mitochondrial concentration of calcium was low and did not change significantly during a tetanus. The TIC of both tetanized and resting freeze-substituted muscles contained electron-lucent circular areas . The appearance of the TIC showed no evidence of major volume changes during tetanus, in agreement with the estimates of unchanged (-72%) water content of the TIC obtained with electron-probe analysis .The release of Ca from and its subsequent return to the triadic portion of the sarcoplasmic reticulum (SR) (28,80,82) are the major determinants of the contractile cycle of striated muscle (for review, see reference 24) . Since the demonstration of the SR as the ATP-dependent relaxing factor (57), a wealth of information has been accumulated about the kinetics and THE JOURNAL OF CELL BIOLOGY " VOLUME 90 SEPTEMBER 1981 577-594 © The Rockefeller University Press -0021-9525/81/09/0577/18 $1 .00 mechanisms of calcium uptake by the SR (e.g., 41,48,63,104,106, and for review, see references 62, 102). In contrast, comparatively little is known about the mechanism of release and associated ion movements, largely because isolated SR preparations do not lend themselves to reproduction of the ph...

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“…In the muscles which had contracted isotonically, several sarcomere patterns were present: (a) sarcomeres 1.6 to 2.0 , in length with 1.3 to 1.5 /, A bands; (b), sarcomeres 1.5 to 1.6 u in length with A bands only 0.7-1.0 /A wide; (c) sarcomeres 1.3 to 1.5 /A wide with contraction bands; and (d) a repeating pattern of light and dark bands with the total width of the two bands equal to 0.8 to 1.0 ,u. The second pattern probably refers to that stage just before the appearance of the CM contraction band (8). The fourth pattern may be the result of extreme shortening to the point where thick and both thin filaments completely span the distances between Z lines and possibly are folded at their ends (22).…”

Section: Autoradiographs Of Muscles Permitted To Shorten During Osmentioning

confidence: 99%

“…The density of grains has been expressed relative to the configuration of thick and thin filaments inferred from the striation pattern (7,8).…”

Section: A Bndmentioning

confidence: 99%

Autoradiographic Studies of Intracellular Calcium in Frog Skeletal Muscle

Winegrad

1965

The Journal of General Physiology

126

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Autoradiographs consisting of a 1000 A thick tissue section and a 1400 A thick emulsion film have been prepared from frog toe muscles labeled with Ca 45 . The muscles had been fixed with an oxalate-containing osmium solution at rest at room temperature, at rest at 4 0°C , during relaxation following K+ depolarization or after prolonged depolarization. From 6 to 39 per cent of K+ contracture tension was produced during fixation. The grains in the autoradiographs were always concentrated in the center 0.2 to 0.3 /A of the I band and the region of the overlapping of the thick and thin filaments. The greater the tension produced during fixation, the greater was the concentration in the A band and the smaller the concentration in the I band. Autoradiographs of two muscles fixed by freeze-substitution resembled those of muscles which produced little tension during osmium fixation. Muscles which shortened during fixation produced fewer grains. In the narrow (<2.0 /j) sarcomeres of the shortened muscles, grain density decreased with decreasing sarcomere width. A theoretical analysis of the significance of these grain distributions is proposed and discussed.A considerable body of evidence has been accumulated to suggest that calcium plays a critical role in excitation-contraction coupling in muscle. Small amounts of calcium are necessary for maximum contraction and maximum adenosine-triphosphatase activity in muscle models (1, 31) Associated with contraction of intact muscle fibers there is an accelerated exchange of calcium probably involving both membrane and intracellular calcium (2, 3). Hill has shown on theoretical grounds that insufficient time exists between membrane depolarization and muscle activation for a substance to diffuse from the cell surface to the cell center (4). Therefore, the "activator" which directly initiates the contraction must either be transmitted by a process faster than diffusion or must be stored inside the cell at a site near the contractile proteins. Huxley and Taylor have shown that the membrane excitation may be con-455

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Measurement of the striations of isolated muscle fibres with the interference microscope

Cited by 89 publications

References 23 publications

Effects of inhomogeneous myofibril morphology on optical diffraction in single muscle fibers

Effects of inhomogeneous myofibril morphology on optical diffraction in single muscle fibers

Calcium release and ionic changes in the sarcoplasmic reticulum of tetanized muscle: an electron-probe study.

Autoradiographic Studies of Intracellular Calcium in Frog Skeletal Muscle

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