Summary
Single or double myofibrils isolated from rabbit psoas muscle were suspended between a fine needle and an optical force transducer. By using a photodiode array, the length of every sarcomere along the specimen could be measured. Relaxed specimens exhibited uniform sarcomere lengths and their passive length-tension curve was comparable to that of larger specimens. Most specimens could be activated and relaxed four to five times before active force levels began to decline; some specimens lasted for 10–15 activation cycles. Active tension (20–22°C) was reproducible from contraction to contraction. The contractile response was dependent on initial sarcomere length. If initially activated at sarcomere lengths of ≥2.7 μm, one group of sarcomeres usually shortened to sarcomere lengths of 1.8–2.0 μm, while the remaining sarcomeres were stretched to longer lengths. Myofibrils that were carefully activated at shorter initial sarcomere lengths usually contracted homogeneously. Both homogeneous and inhomogeneous contractions produced high levels of active tension. Calcium sensitivity was found to be comparable to that in larger preparations; myofibrils immersed in pCa 6.0 solution generated 30% of maximal tension, while pCa 5.5–4.5 resulted in full activation. Active tension at full overlap of thick and thin filaments ranged from 0.34 to 0.94 N mm-2 (mean of 0.59 N mm-2±0.13 sd. n=65). Even allowing for a maximum of 20% nonmyofibrillar space in skinned or intact muscle fibres, the mean tension generated by isolated myofibrils per cross-sectional area is higher than by fibre preparations.
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ANDREWS, M. A. W., MAUGHAN, D. W., NOSEK, T. M. & GODT, R. E. (1991) Ion-specific and general ionic effects on contraction of skinned fast-twitch skeletal muscle from the rabbit. J. Gen. Physiol. 98, 1105–25.
BAGNI, M. A., CECCHI, G., COLOMO, F. & TESI, C. (1988) Plateau and descending limb of the sarcomere length-tension relation in short length-clamped segments of frog muscle fibres. J. Physiol. 401, 581–95.
BRANDT, P. W., DIAMOND, M. S. & SCHACHAT, F. H. (1984) The thin filament of vertebrate skeletal muscle co-operatively activates as a unit. J. Mol. Biol. 180, 379–84.
BRENNER, B. (1983) Technique for stabilizing the striation pattern in maximally calcium-activated skinned rabbit psoas fibers. Biophys. J. 41, 99–102.
BURTON, K., ZAGOTTA, W. N. & BASKIN, R. J. (1989) Sarcomere length behavior along single frog muscle fibres at different lengths during isometric tetani. J. Muscle Res. Cell Motil. 10, 67–84.
CHASE, P. B., MARTYN, D. A., KUSHMERICK, M. J. & GORDON, A. M. (1992) Effects of inorganic phosphate analogues on stiffness and unloaded shortening of skinned muscle fibres from rabbit. J. Phys. (in press).
DEBEER, E. L., GRÜNDEMAN, R. L. F., WILHELM, A. J., VAN DENBERG, C., CALJOUW, C. W., KLEPPER, D. & SHIERECK, P. (1988) Effect of sarcomere length and filament lattice spacing on force development in skinned cardiac and skeletal muscle preparations from the rabbit. Basic Res. Cardiol. 83, 410–23.
DONALDSON, S. K. B. & KERRICK, W. G. L. (1975) Characterization of the effects of Mg2+ on Ca2+ and Sr2+ activated tension generation of skinned skeletal muscle fibers. J. Gen. Physiol. 66, 427–44.
EDMAN, K. A. P. (1971) The velocity of unloaded shortening and its relation to sarcomere length and isometric force in vertebrate muscle fibers. J. Physiol. 291, 143–59.
EISENBERG, B. R. & KUDA, A. M. (1976) Discrimination between fiber pupulations in mammalian skeletal muscle by using ultrastructural parameters. J. Ultrastruct. Res. 54, 76–88.
EISENBERG, B. R., KUDA, A. M. & PETER, J. B. (1974) Stereological analysis of mammalian skeletal muscle. i. Soleus muscle of the adult guinea pig. J. Cell Biol. 60, 732–54.
ELLIOT, G. F., LOWY, J. & MILLMAN, B. M. (1967) Low-angle x-ray diffraction studies of living striated muscle during contraction. J. Mol. Biol. 35, 31–45.
ELZINGA, G., HOWARTH, J. V., RALL, J. A., WILSON, M. G. & WOLEDGE, R. C. (1989) Variation in the normalized tetanic force of single frog muscle fibres. J. Physiol. (Lond.) 410, 157–70.
ELZINGA, G., STIENEN, G. J. & WILSON, M. G. (1989) Isometric force production before and after chemical skinning in isolated muscle fibres of the frog Rana temporaria. J. Physiol. 410, 171–85.
FABIATO, A. & FABIATO, F. (1978) Myofilament-generated tension oscillations during partial calcium activation and activation dependence of the sarcomere length-tension relation of skinned cardiac cells. J. Gen. Physiol. 72, 667–99.
FABIATO, A. & FABIATO, F. (1979) Calculation programs for computing the composition of the solutions containing multiple metals and ligands used for experiments in skinned muscle cells. J. Physiol. 75, 463–505.
FEARN, L. A., BARTOO, M. L., MYERS, J. A. & POLLACK, G. H. (1993) An optical force trans-ducer for single myofibril force measurement. IEEE Trans. (Biomed.) (in press).
FERENCZI, M. A., GOLDMAN, Y. E. & SIMMONS, R. M. (1984) The dependence of force and shortening velocity on substrate concentration in skinned muscle fibres from Rana temporaria. J. Physiol. 350, 519–43.
GORDON, A. M., HUXLEY, A. F. & JULIAN, F. J. (1966) The variation in isometric tension with sarcomere length in vertebrate muscle fibres. J. Physiol. 184, 170–92.
HARADA, Y. & YANAGIDA, T. (1988) Direct observation of molecular motility by light microscopy. Cell Motil. Cytoskel. 10, 71–6.
HARADA, Y., SAKURADA, K., AOKI, T., THOMAS, D. D. & YANAGIDA, T. (1990) Mechano-chemical coupling in actomyosin energy transduction studied by in vitro movement assay. J. Mol. Biol. 216, 49–68.
HELLAM, D. C. & PODOLSKY, R. J. (1969) Force measurements in skinned muscle fibres. J. Physiol. 200, 807–19.
HOMSHER, E., WANG, F. & SELLERS, J. R. (1992) Factors affecting movement of F-actin filaments propelled by skeletal muscle heavy meromyosin. Am. J. Physiol. (Cell Physiol. 31) 262, C714-C723.
HOROWITS, R. (1992) Passive force generation and titin isoforms in mammalian skeletal muscle. Biophys. J. 61, 392–8.
HOROWITS, R. & PODOLSKY, R. J. (1987) The positional stability of thick filaments in activated skeletal muscle depends on sarcomere length: evidence for the role of titin filaments. J. Cell Biol. 105, 2217–23.
ISHIWATA, S., OKAMURA, N., SHIMIZU, H., ANAZAWA, T. & YASUDA, K. (1991) Spontaneous oscillatory contraction (SPOC) of sarcomeres in skeletal muscle. Adv. Biophys. 27, 227–35.
IWAZUMI, T. (1987a) High-speed ultrasensitive instrumentation for myofibril mechanics measurements. Am. J. Physiol. 252, C253-C262.
IWAZUMI, T. (1987b) Mechanics of the myofibril. In Mechanics of the Circulation (edited by TER KEURS, H. E. D. J. & TYBERG, J. V.) pp. 37–49. Dordrecht, the Netherlands: Martinus Nijhoff.
IWAZUMI, T. & POLLACK, G. H. (1981) The effect of sarcomere non-uniformity on the sarcomere length-tension relationship in skinned fibers. J. Cell. Physiol. 106, 321–37.
JULIAN, F. J. & MOSS, R. L. (1981) Effects of calcium and ionic strength on shortening velocity and tension development in frog skinned muscle fibres. J. Physiol. 311, 179–99.
JULIAN, F. J. & MOSS, R. L. (1980) Sarcomere length-tension relations of frog skinned muscle fibres at lengths above the optimum. J. Physiol. 304, 529–39.
KISHINO, A. & YANAGIDA, T. (1988) Force measurements by micromanipulation of a single actin filament by glass needles. Nature 334, 74–6.
KRASNER, B. & MAUGHAN, D. L. (1984) The relationship between ATP hydrolysis and active force in compressed and swollen skinned muscle fibers of the rabbit. Pflügers Arch. 400, 160–5.
LIN, L. E., MCCLELLAN, G. & WINEGRAD, S. (1988) Variation in contractile force with cross-sectioned area in papillary muscle. Biophys. J. 53, 171a.
LINKE, W. A., BARTOO, M. L. & POLLACK, G. H. (1993) Spontaneous sarcomeric oscillations at intermediate activation levels in single isolated cardiac myofibrils. Circ. Res., in press.
McLAUGHLIN, R. J. (1977) Systematic design of cantilever beams for muscle research. J. Appl. Physiol. 42, 786–94.
MARTYN, D. A. & GORDON, A. M. (1988) Length and myofilament spacing-dependent changes in calcium sensitivity of skeletal fibres: effects of pH and ionic strength. J. Muscle Res. Cell Motil. 9, 428–45.
MARTYN, D. A. & GORDON, A. M. (1992) Effects of calcium and elevated phosphate. J. Gen. Physiol. 99, 795–816.
MARUYAMA, K., MATSUNO, A., HIGUCHI, H., SHIMAOKA, S., KIMURA, S. & SHIMIZU, T. (1989) Behaviour of connectin (titin) and nebulin in skinned muscle fibres released after extreme stretch as revealed by immunoelectron microscopy. J. Muscle Res. Cell Motil. 10, 350–9.
MOBLEY, B. A. & EISENBERG, B. R. (1975) Sizes of components in frog skeletal muscle measured by methods of stereology. J. Gen. Phys. 66, 31–45.
MOSS, R. L. (1979) Sarcomere length-tension relations of frog skinned muscle fibers during calcium activation at short lengths. J. Physiol. 292, 177–92.
NOSEK, T. M., FENDER, K. Y. & GODT, R. E. (1987) It is diprotonated inorganic phosphate that depresses force in skinned skeletal muscle fibers. Science 236, 191–3.
NOSEK, T. M., LEAL-CARDOSO, J. H., McLAUGHLIN, M. & Godt, R. E. (1990) Inhibitory influence of phoshate and ardenate on contraction of skinned skeletal and cardiac muscle. Am J. Physiol. 259, C933-C939.
PAGE, S. G. & HUXLEY, H. E. (1963) Filament lengths in striated muscle. J. Cell Biol. 19, 369–90.
ROZYKCA, M. & GONZALEZ-SERRATOS, H. (1993) Non-uniform calcium activation in electrically stimulated, intact frog muscle fibres (submitted).
SALVIATI, G., BETTO, R., CEOLDO, S. & PIEROBON-BORMIOLI, S. (1990) Morphological and functional characterization of the endosarcomeric elastic filament. Am. J. Physiol. (Cell Physiol. 28) 259, C144-C149.
SCHIERECK, P., DEBEER, E. L., GRÜNDEMAN, R. L. F., MANUSSEN, T., KYLSTRA, N. & BRAS, W. (1992) Tetragonal deformation of the hexagonal myofilament matrix in single skeletal muscle fibres owing to change in sarcomere length. J. Muscle Res. Cell Motil. 13, 573–80.
SHARNOFF, M., KARCHER, T. H. & BREHM, L. P. (1984) Microdifferential holography and the polysarcomeric unit of activation of skeletal muscle. Science 223, 822–5.
SPUDICH, J. A., KRON, S. J. & SHEETZ, M. P. (1985) Movement of myosin-coated beads on oriented filaments reconstituted from purified actin. Nature 315, 584–90.
TER KEURS, H. E. D. J., IWAZUMI, T. & POLLACK, G. H. (1978) The sarcomere length-tension relation in skeletal muscle. J. Gen. Physiol. 72, 565–92.
TOYOSHIMA, Y. Y., KRON, S. J. & SPUDICH, J. A. (1988) Observation of in vitro movement of actin filaments directed by myosin fragments bound to a nitrocellulose surface. Cell Motil. Cytoskel. 10, 347.
TROMBITAS, K., BAATSEN, P. H. W. W., KELLERMAYER, M. S. Z. & POLLACK, G. H. (1991) Nature and origin of gap filaments in striated muscle. J. Cell Sci. 100, 809–14.
TUNG, L. (1986) An ultrasensitive transducer for measurement of isometric contractile force from single heart cells. Pflügers Arch. 407, 109–15.
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Bartoo, M.L., Popov, V.I., Fearn, L.A. et al. Active tension generation in isolated skeletal myofibrils. J Muscle Res Cell Motil 14, 498–510 (1993). https://doi.org/10.1007/BF00297212
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DOI: https://doi.org/10.1007/BF00297212