201
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Schiaffino S, Severin E, Cantini M, Sartore S. Tubular aggregates induced by anoxia in isolated rat skeletal muscle. J Transl Med 1977; 37:223-8. [PMID: 895065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The fast-twitch extensor digitorum longus and the slow-twitch soleus muscles of the rat were incubated for 1 to 6 hours in vitro in oxygen-free medium or a medium containing potassium cyanide. Within 3 hours of incubation, characteristic structural alterations of the sarcoplasmic reticulum were observed in extensor digitorum longus muscle fibers. Concomitant with the disruption of the normal sarcotubular organization there was a selective clustering of sarcoplasmic reticulum elements with formation of tubular aggregates similar to those observed in human muscle under various pathologic conditions. The aggregates increased in size by apposition of new tubules at the periphery and acquired a regular hexagonal arrangement. Double-walled tubules, apparently derived from folding of sarcoplasmic reticulum tubules, were also contained in the aggregates. Electron-opaque material was seen connecting adjacent tubules. It is proposed that this material derives from the Z-bands which appeared largely extracted since early stages of anoxic injury. Tubular aggregates were not seen in the soleum muscle fibers incubated under the same conditions in vitro. The results indicate that tubular aggregates can be formed by simple rearrangement of the sarcoplasmic reticulum without proliferation of new sarcotubular elements.
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202
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Burighel P, Nunzi MG, Schiaffino S. A comparative study of the organization of the sarcotubular system in ascidian muscle. J Morphol 1977; 153:205-23. [PMID: 894724 DOI: 10.1002/jmor.1051530204] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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203
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Hanzlíková V, Schiaffino S. Mitochondrial changes in ischemic skeletal muscle. JOURNAL OF ULTRASTRUCTURE RESEARCH 1977; 60:121-33. [PMID: 195077 DOI: 10.1016/s0022-5320(77)80048-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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204
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Abstract
By using a lanthanum-staining technique which enhances the visualization of the plasma membrane and its derivatives we have studied the formation of the T system in rat muscle cells differentiating in vitro. We have found that: (1) T-system formation normally occurs after myoblast fusion and is especially extensive in mature myotubes; myoblasts grown in calcium-deficient medium to prevent fusion show increased number of sarcolemmal caveolae but rare, short T tubules. (2) T-system formation in vitro differs from that displayed by rat muscle cells in vivo in that it precedes and is independent of junctional SR differentiation; the uncoordinated development of T tubules and junctional SR in vitro leads to the formation of 'inverted' triads and labyrinthine T-system networks. (3) Coated vesicles are frequently found either free in the cytoplasm or associated with growing T tubules in rat muscle cells differentiating in vitro. A role of coated vesicles in T-system formation is proposed.
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205
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Schiaffino S, Bormioli SP, Aloisi M. The fate of newly formed satellite cells during compensatory muscle hypertrophy. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1976; 21:113-8. [PMID: 822576 DOI: 10.1007/bf02899148] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Compensatory hypertrophy was induced in the rat extensor digitorum longus muscle by extirpation of the synergistic tibialis anterior. Injections of 3H-thymidine (2 muCi/g body weight) was given at 24, 48, and 72 h after the operation. In animals killed immediately after the last injection both satellite cell nuclei and true muscle nuclei were labeled, whereas in animals killed 4 weeks later only true muscle nuclei were labeled. The results are interpreted as indicating incorporation of newly formed satellite cells into the fibers during compensatory hypertrophy.
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206
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Schiaffino S, Pierobon Bormioli S. Morphogenesis of rat muscle spindles after nerve lesion during early postnatal development. JOURNAL OF NEUROCYTOLOGY 1976; 5:319-36. [PMID: 133212 DOI: 10.1007/bf01175118] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The influence of innervation on muscle spindle morphogenesis has been investigated in rat hind-limb muscles by sectioning the sciatic nerve, with suture of the stumps, at various postnatal stages. After nerve section at 4 or 7 days of age a proportion of spindles survived during the denervation phase and developed, during the subsequent reinnervation phase, into atypical structures. The reinnervated spindles were recognized by the presence of a limiting capsule but lacked the characteristic distinction of equatorial and polar regions. The intrafusal fibres were fewer than normal and were indistinguishable in size and fine structure from extrafusal fibres; they had a single motor endplate and lacked sensory nerve terminals. In reinnervated muscles of animals operated at 13 and 22 days of age there was a progressive tendency towards a restoration of normal spindle structure and innervation. These findings indicate that muscle spindle morphogenesis is profoundly altered by nerve lesion at early development stages, apparently as a result of inadequate sensory reinnervation. This study also shows that the differentiation of intrafusal fibres is dictated by their specific pattern of innervation and is not intrinsically predetermined.
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207
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Schiaffino S, Nunzi MG, Burighel P. T system in ascidian muscle: organization of the sarcotubular system in the caudal muscle cells of Botryllus schlosseri tadpole larvae. Tissue Cell 1976; 8:101-10. [PMID: 1265732 DOI: 10.1016/0040-8166(76)90023-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The organization of the sarcotubular system has been examined in the caudal muscle cells of the ascidian. Botryllus schlosseri. At variance with striated muscle of other protochordates. Botryllus muscle cells are endowed with a well-developed T system, which has a peculiar laminar structure. The thin T laminae are in continuity with the plasma membrane and extend longitudinally in the intermyofibrillar spaces. At the level of the I-band the T laminae are focally associated with SR cisternae in dyad junctions similar to those observed in invertebrate muscles. These findings are discussed in relation to the origin of the sarcotubular system in vertebrate muscle.
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208
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Schiaffino S, Sjöström M, Thornell LE, Nyström B, Hackelius L. The process of survival of denervated and freely autotransplantated skeletal muscle. EXPERIENTIA 1975; 31:1328-30. [PMID: 1204794 DOI: 10.1007/bf01945810] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The study shows that two distinct processes occur in free autografts of denervated intact muscle during the early critical phase of the transplantation: survival of transplanted fibres at the periphery of the graft, and regeneration of new muscle fibres following breakdown of the originally transplanted fibres in the central areas.
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209
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Schiaffino S, Burighel P, Nunzi MG. Involution of the caudal musculature during metamorphosis in the ascidian, Botryllus schlosseri. Cell Tissue Res 1974; 153:293-305. [PMID: 4458948 DOI: 10.1007/bf00229160] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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210
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Schiaffino S. Hypertrophy of skeletal muscle induced by tendon shortening. EXPERIENTIA 1974; 30:1163-4. [PMID: 4435123 DOI: 10.1007/bf01923666] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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211
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Schiaffino S. Histochemical enzyme profile of the masseter muscle in different mammalian species. Anat Rec (Hoboken) 1974; 180:53-61. [PMID: 4137704 DOI: 10.1002/ar.1091800107] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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212
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Hanzlíková V, Schiaffino S. Studies on the effect of denervation in developing muscle. 3. Diversification of myofibrillar structure and origin of the heterogeneity of muscle fiber types. ZEITSCHRIFT FUR ZELLFORSCHUNG UND MIKROSKOPISCHE ANATOMIE (VIENNA, AUSTRIA : 1948) 1973; 147:75-85. [PMID: 4788296 DOI: 10.1007/bf00306601] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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213
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Schiaffino S, Bormioli SP. Adaptive changes in developing rat skeletal muscle in response to functional overload. Exp Neurol 1973; 40:126-37. [PMID: 4268357 DOI: 10.1016/0014-4886(73)90129-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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214
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Schiaffino S, Bormioli SP. Histochemical characterization of adenosine triphosphatases in skeletal muscle fibers by selective extraction procedures. J Histochem Cytochem 1973; 21:142-5. [PMID: 4266543 DOI: 10.1177/21.2.142] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Selective extraction procedures have been applied to frozen sections of rat skeletal muscles to determine the relative contribution of myosin adenosine triphosphatase (ATPase) and of membrane-bound (mitochondrial and sarcotubular) ATPases to the histochemical ATPase reactions demonstrated in muscle fibers by the calcium precipitatation mehod (Padykula-Herman procedure) and by the lead precipitation medium (Wachstein-Meisel procedure). A detergent treatment was used to solubilize membrane-bound enzymes and hypertonic KCl solution to extract myosin. Pretreatment with the non-ionic detergent, Triton X-100, severely depressed the ATPase activity demonstrated by the lead method, as well as several membrane-bound dehydrogenase activities, but did not affect the intensity of the ATPase reaction demonstrated in the muscle fibers by the calcium method. After detergent treatment, however, the end product of the latter reaction showed a network distribution which contrasted with the characteristic myofibrillar localization observed in untreated sections. Hypertonic KCl pretreatment, when applied to undried sections, abolished the ATPase reaction demonstrated in the muscle fibers by the calcium method; the ATPase demonstrated by the lead method was slightly depressed and the dehydrogenase activities unmodified by the same treatment. The results indicate that the ATPase activity demonstrated histochemically in skeletal muscle fibers by the calcium method is due to myosin ATPase, and suggest that the intermyofibrillar localization of the end product which occurs under certain conditions is artifactual.
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215
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Schiaffino S, Bormioli SP, Aloisi M. Cell proliferation in rat skeletal muscle during early stages of compensatory hypertrophy. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1972; 11:268-73. [PMID: 4628775 DOI: 10.1007/bf02889406] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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216
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Schiaffino S, Hanzlíková V. Studies on the effect of denervation in developing muscle. II. The lysosomal system. JOURNAL OF ULTRASTRUCTURE RESEARCH 1972; 39:1-14. [PMID: 5017036 DOI: 10.1016/s0022-5320(72)80002-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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217
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Schiaffino S, Hanzlíková V. Autophagic degradation of glycogen in skeletal muscles of the newborn rat. J Biophys Biochem Cytol 1972; 52:41-51. [PMID: 4331300 PMCID: PMC2108668 DOI: 10.1083/jcb.52.1.41] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Large amounts of glycogen accumulate in rat skeletal muscle fibers during the late fetal stages and are mobilized in the first postnatal days. This glycogen depletion is relatively slow in the immature leg muscles, in which extensive deposits are still found 24 hr after birth and, to some extent, persist until the 3rd day. In the more differentiated psoas muscle and especially in the diaphragm, the glycogen stores are completely mobilized already during the early hours. Section of the sciatic nerve 3 days before birth or within the first 2 hr after delivery does not affect glycogen depletion in the leg muscles. Neonatal glycogenolysis in rat muscle fibers takes place largely by segregation and digestion of glycogen particles in autophagic vacuoles. These vacuoles: (a) are not seen in fetal muscle fibers or at later postnatal stages, but appear concomitantly with the process of glycogen depletion and disappear shortly afterwards; (b) are prematurely formed in skeletal muscles of fetuses at term treated with glucagon; (c) contain almost exclusively glycogen particles and no other recognizable cell constituents; (d) have a double or, more often, single limiting membrane and originate apparently from flattened sacs sequestering glycogen masses; (e) are generally found to contain reaction product in preparations incubated from demonstration of acid phosphatase activity. The findings emphasize the role of the lysosomal system in the physiological process of postnatal glycogen mobilization and appear relevant in the interpretation of type II glycogen storage disease.
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218
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Aloisi M, Schiaffino S. Growth of elementary blood vessels in diffusion chambers. II. Electron microscopy of capillary morphogenesis. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1971; 8:328-41. [PMID: 4998662 DOI: 10.1007/bf02893542] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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219
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Gutmann E, Schiaffino S, Hanzliková V. Mechanism of compensatory hypertrophy in skeletal muscle of the rat. Exp Neurol 1971; 31:451-64. [PMID: 4254915 DOI: 10.1016/0014-4886(71)90248-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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220
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Schiaffino S, Hanzlíková V, Pierobon S. Relations between structure and function in rat skeletal muscle fibers. J Cell Biol 1970; 47:107-19. [PMID: 5513549 PMCID: PMC2108409 DOI: 10.1083/jcb.47.1.107] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus muscle of the rat consist of heterogeneous fiber populations. EDL muscle fibers differ in size, mitochondrial content, myoglobin concentration, and thickness of the Z line. The sarcoplasmic reticulum, on the other hand, is richly developed in all fibers, with only small variation. Myofibrils are clearly circumscribed at both the A and I band level. The soleus muscle is composed primarily of fibers with moderate mitochondrial content and myoglobin concentration. In most fibers the sarcoplasmic reticulum is poorly developed, with the exception of the portion of reticulum in phase with the Z line. As a consequence the myofibrillar fields are amply fused together. Contacts between sarcoplasmic reticulum and T system are discontinuous and may occur in the form of "dyads" instead of the typical triad structure. In a small proportion of soleus muscle fibers the organization and development of the sarcoplasmic reticulum is similar to that of EDL muscle fibers, with prominent fenestrated collars at the H band level. In these fibers mitochondria are larger and more abundant. The results are correlated with physiological studies on motor units in the same and in similar rat muscles. It is suggested that the variable structural pattern of rat muscle fibers is related to two distinct physiological parameters, speed of contraction and resistance to fatigue.
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221
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Schiaffino S, Hanzlíková V. On the mechanism of compensatory hypertrophy in skeletal muscles. EXPERIENTIA 1970; 26:152-3. [PMID: 5413776 DOI: 10.1007/bf01895548] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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222
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Hanzlíková V, Schiaffino S, Settembrini P. Histochemical fiber types characteristics in the normal and the persistent levator ani muscle of the rat. HISTOCHEMIE. HISTOCHEMISTRY. HISTOCHIMIE 1970; 22:45-50. [PMID: 4245675 DOI: 10.1007/bf00310549] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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223
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Schiaffino S, Settembrini P. Studies on the effect of denervation in developing muscle. I. Differentiation of the sarcotubular system. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1969; 4:345-56. [PMID: 4984393 DOI: 10.1007/bf02906089] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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224
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Schiaffino S, Margreth A. Coordinated development of the sarcoplasmic reticulum and T system during postnatal differentiation of rat skeletal muscle. J Biophys Biochem Cytol 1969; 41:855-75. [PMID: 5814005 PMCID: PMC2107825 DOI: 10.1083/jcb.41.3.855] [Citation(s) in RCA: 139] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
An electron microscope study has been carried out on rat psoas muscle, during the early postnatal stages of development. Among the several subcellular components, the sarcotubular system undergoes the most striking modifications during this period. In muscle fibers of the newborn rat, junctional contacts between the T system and the SR are sparse and are, mostly, longitudinally or obliquely oriented. The T tubules do not penetrate deeply into the muscle cell, as indicated by the predominantly peripheral location of the triads and the persistence, at these stages of development, of a highly branched subsarcolemmal system of tubules. Diadic associations of junctional SR elements with the plasma membrane are also occasionally observed. The early SR elaborations incompletely delineate the myofibrils, at both the A- and I-band level. Longitudinal sections show irregularly oriented SR tubules, running continuously over successive sarcomeres. Flattened junctional cisterns filled with granular material are sparse and laterally interconnected, at circumscribed sites, with the SR tubules. Between 1 and 2 wk postpartum, transversal triadic contacts are extensively established, at the A-I band level, and the SR network differentiates into two portions in register with the A and I band, respectively. At 10-15 days after birth, the SR provides a transversely continuous double sheet around the myofibrils at the I-band level, whereas it forms a single discontinuous layer at the A-band level. The relationship that these morphological modifications of the sarcotubular system may bear to previously described biochemical and physiological changes of rat muscle fibers after birth is discussed.
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