Summary
The papillary muscle of the heart of adult white mice is investigated. Intrafibrillarly located leptomeric fibrils, frequently encountered in the Z-band region of the myofibrils. The leptomeric fibrils are always running in a transverse direction and often in close proximity to the transverse tubules (which are also located at this level). There seems to be a close connection between the dense striae of the leptofibrils and the Z-bands of ordinary myofibrils. The leptomeric fibrils are spindle-shaped and have a length varying between 0.6 and 1.2 μm. The banding periodicity of the fibrils is approximately 0.16 μm.
Occasionally desmosomes are observed in the T-tubule system.
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Bogusch, G.: Electron microscopic investigation on leptomeric fibrils and leptomeric complexes in the hen and pigeon heart. J. molec. Cell. Card. 7, 733–745 (1975)
Bogusch, G.: Enzymatic digestion and urea extraction on leptomeric structures and normomeric myofibrils in heart muscle cells. J. Ultrastruct. Res. 55, 245–256 (1976)
Buja, L.M., Ferrans, J.V., Maron, B.J.: Intracytoplasmic junctions in cardiac muscle cells. Amer. J. Path. 74, 613–648 (1974)
Caesar, R., Edwards, G.E., Ruska, H.: Electron microscopy of the impulse conducting system of the sheep heart. Z. Zellforsch. 48, 698–719 (1958)
Foroglou, C., Winckler, G.: Ultrastructure du fuseau neuromusculaire chez l'homme. Comparaison avec le rat. Z. Anat. Entwickl.-Gesch. 140, 19–37 (1973)
Gossrau, R.: Über das Reizleitungssystem der Vögel. Histochemische and elektronenmikroskopische Untersuchungen. Histochemie 13, 111–159 (1968)
Gruner, J.E.: La structure fine du fuseau neuromusculaire humain. Rev. Neurol. (Paris) 104, 490–507 (1961)
Hirakow, R.: Fine structure of Purkinje fibres in the chick heart. Arch. Histol. Jap. 27, 485–499 (1966)
Johnson, E.A., Sommer, J.R.: A strand of cardiac muscle. Its ultrastructure and the electrophysiological implications of its geometry. J. Cell Biol. 33, 103–129 (1967)
Karlsson, U.L., Andersson-Cedergreen, E.: Small leptomeric organelles in intrafusal muscle fibers of the frog as revealed by electron microscopy. J. Ultrastruct. Res. 23, 417–426 (1968)
Karlsson, U.L., Hooker, W.M., Bendeich, E.G.: Quantitative changes in the frog muscle spindle with passive stretch. J. Ultrastruct. Res. 36, 743–756 (1971)
Katz, B.: The terminations of the afferent nerve fiber in the muscle spindle of the frog. Philos. Trans. roy. Soc. B 243, 221–240 (1961)
Kawamura, K.: Electron microscope studies on the cardiac conduction system of the dog. I. The Purkinje fibers. Jap. Circ. J. 25, 594–616 (1961)
Kelly, A.M., Chacko, S.: Internal membrane junctions and unusual T-tubules in cultured chick cardiac muscle cells. J. molec. Cell. Card. 9, 419–424 (1977)
Konishi, A., Beacham, W.S., Hunt, C.C.: Centrioles in intrafusal muscle fibers. J. Cell Biol. 59, 749–755 (1973)
Landon, D.N.: Electron microscopy of muscle spindles. In: Control and Innervation of Skeletal Muscle. A Symposium at Queen's College, Dundee, September 1965 (B.L. Andrew, ed,), pp. 96–110. Dundee: Thompson & Co. Ltd. 1966
Maron, B.J., Ferrans, V.J., Roberts, W.C.: Ultrastructural features of degenerated cardiac muscle cells in patients with cardiac hypertrophy. Amer. J. Path. 79, 387–434 (1975)
Mercer, E.M., Birbeck, M.S.C.: Electron microscopy, A handbook for biologists. 3rd ed., 103p. Oxford: Blackwell Scientific Publications 1972
Myklebust, R., Sætersdal, T.S., Engedal, H., Ulstein, M., Ødegården, S.: Ultrastructural studies on the formation of myofilaments and myofibrils in the human embryonic and adult hypertrophied heart. Anat. Embryol. 152, 127–140 (1978)
Ovalle, W.K.: Fine structure of rat intrafusal muscle fibers. The equatorial region. J. Cell Biol. 52, 382–396 (1972)
Page, E., Power, B., Fozzard, H.A., Meddoff, C.A.: Sarcolemmal evaginations with knob-like or stalked projections in Purkinje fibers of the sheep's heart. J. Ultrastruct. Res. 28, 288–300 (1969)
Rumpelt, H.J., Schmalbruch, H.: Zur Morphologie der Bauelemente von Muskelspindeln bei Mensch und Ratte. Z. Zellforsch. 102, 601–630 (1969)
Ruska, H., Edwards, G.A.: A new cytoplasmic pattern in striated muscle fibers and its possible relation to growth. Growth 21, 73–80 (1957)
Sætersdal, T.S., Myklebust, R.: Ultrastructure of the pigeon papillary muscle with special reference to the sarcoplasmic reticulum. J. molec. Cell. Card. 7, 543–551 (1975)
Sætersdal, T.S., Myklebust, R., Skagseth, E., Engedal, H.: Ultrastructural studies on the growth of filaments and sarcomeres in mechanically overloaded human hearts. Virchows Arch. B, Cell Path. 21, 91–112 (1976)
Scott, T.M.: The ultrastructure of ordinary and Purkinje cells of the fowl heart. J. Anat. 110, 259–273 (1971)
Thoenes, W., Ruska, H.: Über “leptomere Myofibrillen” in der Herzmuskelzelle. Z. Zellforsch. 51, 560–570 (1960)
Thornell, L.E.: Ultrastructural variations of Z-bands in cow Purkinje fibres. J. molec. Cell. Card. 5, 409–417 (1973)
Virágh, S., Challice, C.E.: Variations in filamentous and fibrillar organization, and associated sarcolemmal structures in cells of the normal mammalian heart. J. Ultrastruct. Res. 28, 321–334 (1969)
Virágh, S., Challice, C.E.: The impulse generation and conduction system of the heart. In: Ultrastructure in Biological Systems. (A.J. Dalton and F. Hagueneau, eds.) Volume 6: Ultrastructure of the Mammalian Heart (C.E. Challice and S. Virágh, eds.), pp. 43–89. New York-London: Academic Press 1973
Walker, S.M., Schrodt, G.R., Currier, G.J.: Evidence for a structural relationship between successive parallel tubules in the SR network and supernumerary striations of Z line material in Purkinje fibers of the chicken, sheep, dog and rhesus monkey heart. J. Morph. 147, 459–473 (1975)
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Myklebust, R., Jensen, H. Leptomeric fibrils and T-tubule desmosomes in the Z-band region of the mouse heart papillary muscle. Cell Tissue Res. 188, 205–215 (1978). https://doi.org/10.1007/BF00222631
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DOI: https://doi.org/10.1007/BF00222631