scholarly journals Effect of the bendiocarb on the ultrastructure of rabbit skeletal muscle

2017 ◽  
Vol 86 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Katarína Holovská ◽  
Viera Almášiová ◽  
Lucia Tarabová ◽  
Eva Petrovová ◽  
Viera Cigánková
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Body Weight ◽  
Sarcoplasmic Reticulum ◽  
Skeletal Muscles ◽  
Ultrastructural Changes ◽  
Muscle Fibres ◽  
Carbamate Insecticides ◽  
Cytoplasmic Vesicles ◽  
Membrane Bound

Bendiocarb belongs to the group of carbamate insecticides that inhibit acetylcholinesterase. In agriculture, it is used to control a variety of insects, therefore it is important to examine every potential aspect of its toxicology. The aim of this study was to observe the effect of bendiocarb on the ultrastructure of the skeletal muscle in rabbits. Rabbits in all experimental groups received capsules of bendiocarb (96% Bendiocarb, Bayer, Germany) per os daily at a dose of 5 mg/kg body weight. Samples of skeletal muscles were collected on days 10 and 20. On day 10 of the experiment, muscle fibres were not affected consistently. The observed changes were moderate and focal. Electron microscopy revealed dilatation of sarcoplasmic reticulum, and myofilament disorganization. On day 20 of the experiment, the ultrastructural changes in muscle fibres were more intense and more frequent. The most important alteration was the disruption of the sarcomeres due to the lysis of both thick and thin myofilaments. However, in the unchanged regions of muscle fibres a prominent mitochondrial swelling was observed. Many mitochondria lacked cristae and thus appeared as large membrane-bound cytoplasmic vesicles. The results presented in this study indicate that bendiocarb affects the ultrastructure of skeletal muscles. The intensity of damage (dissolution of myofilaments and disruption of sarcomeres) was related to the duration of administration of bendiocarb.

scholarly journals Vesicle budding from endoplasmic reticulum is involved in calsequestrin routing to sarcoplasmic reticulum of skeletal muscles

2004 ◽  
Vol 379 (2) ◽  
pp. 505-512 ◽  
Author(s):  
Alessandra NORI ◽  
Elena BORTOLOSO ◽  
Federica FRASSON ◽  
Giorgia VALLE ◽  
Pompeo VOLPE
Keyword(s):  
Skeletal Muscle ◽  
Endoplasmic Reticulum ◽  
Sarcoplasmic Reticulum ◽  
Golgi Complex ◽  
Skeletal Muscles ◽  
Muscle Fibres ◽  
Vesicle Budding ◽  
Er Exit Sites ◽  
Skeletal Muscle Fibres ◽  
Mutant Forms

CS (calsequestrin) is an acidic glycoprotein of the SR (sarcoplasmic reticulum) lumen and plays a crucial role in the storage of Ca2+ and in excitation–contraction coupling of skeletal muscles. CS is synthesized in the ER (endoplasmic reticulum) and is targeted to the TC (terminal cisternae) of SR via mechanisms still largely unknown, but probably involving vesicle transport through the Golgi complex. In the present study, two mutant forms of Sar1 and ARF1 (ADP-ribosylation factor 1) were used to disrupt cargo exit from ER-exit sites and intra-Golgi trafficking in skeletal-muscle fibres respectively. Co-expression of Sar1-H79G (His79→Gly) and recombinant, epitope-tagged CS, CSHA1 (where HA1 stands for nine-amino-acid epitope of the viral haemagglutinin 1), barred segregation of CSHA1 to TC. On the other hand, expression of ARF1-N126I altered the subcellular localization of GM130, a cis-medial Golgi protein in skeletal-muscle fibres and myotubes, without interfering with CSHA1 targeting to either TC or developing SR. Thus active budding from ER-exit sites appears to be involved in CS targeting and routing, but these processes are insensitive to modification of intracellular vesicle trafficking and Golgi complex disruption caused by the mutant ARF1-N126I. It also appears that CS routing from ER to SR does not involve classical secretory pathways through ER–Golgi intermediate compartments, cis-medial Golgi and trans-Golgi network.

Effects of altitude acclimatization on rat myoglobin. Changes in myoglobin content of skeletal and cardiac muscle

1959 ◽  
Vol 196 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Adam Anthony ◽  
Eugene Ackerman ◽  
G. K. Strother
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Cardiac Muscle ◽  
Water Content ◽  
Skeletal Muscles ◽  
The Body ◽  
Continuous Exposure ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Muscle Weight

Analyses were made of myoglobin content of rat skeletal and cardiac muscle following continuous exposure to simulated altitudes of 18,000 feet for a 2–10-week period. About five dozen rats were used. Acclimatization was associated with an increase in the myoglobin concentration of thigh, diaphragm, gastrocnemius and heart muscles. Total myoglobin content, however, increased during acclimatization in cardiac muscle but not in the three skeletal muscles. This finding together with the body weight changes and muscle weight changes suggested that the increases in myoglobin concentration of skeletal muscle may be merely a reflection of a decreased water content of muscles.

Chimeric calsequestrin and its targeting to the junctional sarcoplasmic reticulum of skeletal muscle

1997 ◽  
Vol 272 (5) ◽  
pp. C1420-C1428 ◽  
Author(s):  
A. Nori ◽  
K. A. Nadalini ◽  
A. Martini ◽  
R. Rizzuto ◽  
A. Villa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Confocal Microscopy ◽  
Soleus Muscle ◽  
Hela Cells ◽  
Skeletal Muscles ◽  
Intracellular Localization ◽  
Primary Cultures ◽  
Muscle Fibers ◽  
Junctional Sarcoplasmic Reticulum

Calsequestrin (CS) is the junctional sarcoplasmic reticulum (jSR) Ca2+ binding protein responsible for intraluminal Ca2+ storage. The targeting mechanisms of CS to the jSR are yet to be unraveled. The nine-amino acid epitope of the influenza virus hemoagglutinin (referred to as HA1) was added at the COOH-terminal of CS by polymerase chain reaction cloning. The HA1-tagged CS cDNA was transiently transfected in either HeLa cells, myogenic cell lines, such as C2 and L8 cells, myoblasts of rat skeletal muscle primary cultures, or regenerating soleus muscle fibers of adult rats. The expression and intracellular localization of chimeric CS-HA1 were monitored by epifluorescence and confocal microscopy using either anti-CS antibodies or anti-HA1 antibodies. About 30% of transfected HeLa cells and 20-40% of myogenic cells expressed CS-HA1 into intracellular compartments, such as the perinuclear cisternae of endoplasmic reticulum (ER). Myoblasts of newborn rat skeletal muscles were first transfected and subsequently stimulated to differentiate into myotubes. CS-HA1 was detected in approximately 20% of transfected myotubes and did not affect CS distribution in myotubes. In the soleus muscle of adult rat, intramuscular injection of bupivacaine induced necrosis followed by regeneration. In vivo transfection of HA1-tagged CS cDNA in regenerating skeletal muscles determined expression in a few skeletal muscle fibers; CS-HA1 was localized only in jSR, as judged by confocal microscopy of longitudinal sections. The present results show that chimeric CS-HA1 is correctly sorted to ER/SR compartments and that the free COOH-terminal is not requested for sorting, retention, and segregation of CS to the SR.

Rapid anisotropic motion of the Ca2+-transport ATPase of the rabbit skeletal muscle sarcoplasmic reticulum

1977 ◽  
Vol 55 (6) ◽  
pp. 587-596 ◽  
Author(s):  
Barbara A. Manuck ◽  
Brian D. Sykes
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Relaxation Times ◽  
Rotational Correlation Time ◽  
Rabbit Skeletal Muscle ◽  
Nuclear Spin Relaxation ◽  
Anisotropic Model ◽  
Transport Atpase ◽  
Anisotropic Motion ◽  
Membrane Bound

1H nuclear magnetic resonance techniques were used to study the binding of uridine 5′-triphosphate to the Ca2+-transport ATPase (EC 3.6.1.3) of sarcoplasmic reticulum vesicles from rabbit skeletal muscle. The nuclear spin relaxation times determined for the bound nucleotide are used to characterize the rotational motion of the ATPase to which the nucleotide is bound. The results, assuming an anisotropic model for the motion of the ATPase in the membrane, place a low upper limit on the rotational correlation time of the ATPase. This indicates that the motion of the ATPase in the membrane is quite rapid when compared, for example, with the motion found for other membrane-bound proteins such as rhodopsin.

scholarly journals Preparation and morphology of sarcoplasmic reticulum terminal cisternae from rabbit skeletal muscle.

1984 ◽  
Vol 99 (3) ◽  
pp. 875-885 ◽  
Author(s):  
A Saito ◽  
S Seiler ◽  
A Chu ◽  
S Fleischer
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Thin Section ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Morphological Characteristics ◽  
Negative Staining ◽  
Section Electron ◽  
Terminal Cisternae

We have developed a procedure to isolate, from skeletal muscle, enriched terminal cisternae of sarcoplasmic reticulum (SR), which retain morphologically intact junctional "feet" structures similar to those observed in situ. The fraction is largely devoid of transverse tubule, plasma membrane, mitochondria, triads (transverse tubules junctionally associated with terminal cisternae), and longitudinal cisternae, as shown by thin-section electron microscopy of representative samples. The terminal cisternae vesicles have distinctive morphological characteristics that differ from the isolated longitudinal cisternae (light SR) obtained from the same gradient. The terminal cisternae consist of two distinct types of membranes, i.e., the junctional face membrane and the Ca2+ pump protein-containing membrane, whereas the longitudinal cisternae contain only the Ca2+ pump protein-containing membrane. The junctional face membrane of the terminal cisternae contains feet structures that extend approximately 12 nm from the membrane surface and can be clearly visualized in thin section through using tannic acid enhancement, by negative staining and by freeze-fracture electron microscopy. Sections of the terminal cisternae, cut tangential to and intersecting the plane of the junctional face, reveal a checkerboardlike lattice of alternating, square-shaped feet structures and spaces each 20 nm square. Structures characteristic of the Ca2+ pump protein are not observed between the feet at the junctional face membrane, either in thin section or by negative staining, even though the Ca2+ pump protein is observed in the nonjunctional membrane on the remainder of the same vesicle. Likewise, freeze-fracture replicas reveal regions of the P face containing ropelike strands instead of the high density of the 7-8-nm particles referable to the Ca2+ pump protein. The intravesicular content of the terminal cisternae, mostly Ca2+-binding protein (calsequestrin), is organized in the form of strands, sometimes appearing paracrystalline, and attached to the inner face of the membrane in the vicinity of the junctional feet. The terminal cisternae preparation is distinct from previously described heavy SR fractions in that it contains the highest percentage of junctional face membrane with morphologically well-preserved junctional feet structures.

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