Browsing by Subject "Smooth muscle"

Now showing 1 - 4 of 4
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    Matrix production of smooth muscle cells from rat aorta in vitro
    (Murcia : F. Hernández, 1993) Stieme, B.; Springmeier, G.; El-Jarad, L.; Schroter-Kermani, C.
    Immunofluorescence microscopic methods served to demonstrate the production of the following matrix components in cultures of vascular smooth muscle cells from rat aorta: fibronectin; nidogen; heparan sulphate-proteoglycan (HS-PG); laminin; and collagen types 1, 111, IV, V, and VI. A time-dependence of synthesis and secretion could be shown for a number of components of the extracellular matrix (ECM), such as laminin. The results revealed the following estimated quantitative differences of the collagen types: type 1 > type 111 > types V and VI. A filamentouslfibrillar matrix and also occasionally a typical basal lamina could be demonstrated electron microscopically around the smooth muscle cells.
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    Smooth muscle distribution in the capsule and trabeculae of the caprine superficial cervical lymph node
    (Murcia : F. Hernández, 1987) Faroon, O. M.; Henry, R. W.; Al-Bagdadi, F.K.
    This study centers around the dichotomy found in the literature concerning the presence of smooth muscle cells in the trabeculae and capsule of lymph nodes. Various superficial lymph nodes (mammary, mandibular, popliteal, subiliac, and superficial cervical) of the goat were collected and examined by light and electron microscopy. Smooth muscle cells were demonstrated in the capsule and trabeculae of lymph nodes independent of the blood and lymph vessels
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    Telocytes in skeletal, cardiac and smooth muscle interstitium: morphological and functional aspects
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Marini, Mirca; Rosa, Irene; iIbba Mannesch, Lidia; Manetti, Mirko
    Telocytes (TCs) represent a new distinct type of cells found in the stromal compartment of many organs, including the skeletal, cardiac and smooth muscles. TCs are morphologically defined as interstitial cells with a small cellular body from which arise very long (up to hundreds of micrometers) and thin moniliform processes (named telopodes) featuring the alternation of slender segments (called podomers) and small dilated portions (called podoms) accommodating some organelles. Although these stromal cells are mainly characterized by their ultrastructural traits, in the last few years TCs have been increasingly studied for their immunophenotypes, microRNA profiles, and gene expression and proteomic signatures. By their longdistance spreading telopodes, TCs build a threedimensional network throughout the whole stromal space and communicate with each other and neighboring cells through homocellular and heterocellular junctions, respectively. Moreover, increasing evidence suggests that TCs may exert paracrine functions being able to transfer genetic information and signaling molecules to other cells via the release of different types of extracellular vesicles. A close relationship between TCs and stem/progenitor cell niches has also been described in several organs. However, the specific functions of TCs located in the muscle interstitium remain to be unraveled. Here, we review the morphological and possible functional aspects of TCs in skeletal, cardiac and smooth muscle tissues. The potential involvement of TCs in muscle tissue pathological changes and future possibilities for targeting TCs as a novel promising therapeutic strategy to foster muscle tissue regeneration and repair are also discussed.
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    Ultrastructure of invertebrate muscle cell types
    (Murcia : F. Hernández, 1996) Paniagua, R.; Royuela, M.; García-Anchuelo, R.M.; Fraile, Benito
    The muscular cells of invertebrates can be divided into three major classes on the basis of their striation pattem: transversely striated, obliquely striated, or smooth muscle. Transversely striated muscles have either continuous or discontinuous Z lines and, thus, can be subdivided into two types respectively. Of al1 invertebrate muscles, the transversely striated muscle with continuos Z lines is the most similar to the vertebrate skeletal muscle and is present in arthropods, whose musculature (including the visceral muscles) only consists of this cell type. These muscles are multinucleate cells that contain myofibrils showing welldefined sarcomeres. Transversely striated muscles with discontinuous Z lines, consisting of multiple small electrondense patches, are found in the translucent portions of adductor muscles of some bivalves and in the heart muscle of the gastropods. This muscle is formed by mononucleated cells with centrally-located nuclei and a single myofibril. The obliquely striated muscle appears in nematodes, annelids, molluscs, brachiopods and chaetognathes and consists of mononucleated cells with both thick and thin myofilaments which form sarcomeres delimited by Z lines. Myofilaments are not perpendicular but oblique to the Z lines, so that both A and 1 bands may be seen together in each of the three spatial planes of view. Smooth muscle has been reported in coelenterates, annelids, molluscs, brachiopods and echinoderms, but is lacking in arthropods. These muscle cells have a centrally-located nucleus and abundant thin and thick myofilaments without apparent sarcomeres. The most relevant characteristics of invertebrate muscle cells are the following. The thick (myosin) myofilarnents show a variable length (from 2.2 pm up to 6 pm) and width (from 14 nm up to 231 nm) and contain a central core of paramyosin, which is absent in vertebrate muscles. Thick filaments are homogenous in transversely striated muscles and either homogeneous or fusiform in the obliquely striated and smooth muscles. Thin filaments measure 6 nm in diameter. They contain tropomyosin and, only in striated muscles, also troponin. The thinlthick filament ratio varies from 311 to 611, even in smooth muscles. The plaques for filament anchorage (Z lines in striated muscles or electrondense bodies in smooth muscles) contain a-actinin. The striated (transversely or obliquely) muscles show long sarcomeres (up to 9 pm) and the number of thin filaments around each thick filament varies from 3 to 12, so that each thin filament is shared by two thick filaments. Z lines in the striated muscles show a variety of structures that differ from one species to another (filament bundles in nematodes, bars in annelids, small patches in molluscs, etc). Many striated muscles contain titin (connectin) and intermediate filaments and display a sarcotubular system consisting of T tubules and sarcoplasmic reticulum tubules. Both structures form dyads and, more rarely, triads. The location of T tubules as well as the configuration and distribution of sarcoplasmic reticulum vary among muscles and species. Invertebrate smooth muscle differs from that of vertebrates principally in the higher proportion and larger diameter of thick myofilaments. These may be fusiform and their size and number may vary widely among cells. These muscle cells may be classified by the characteristics of both the thick filaments and the electrondense bodies for filament anchorage.