• Biomedical Science Letters
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• v.13 no.4
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• pp.251-261
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• 2007

A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.175.1-175
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• 1994

No Abstract, See Full Text

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.295-305
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• 1977

The procedures for the Preparation of regulatory proteins of myofibrill were developed and postmortem changes in the regulatory proteins of myofibrill were investigated. Both the physiological property and molecular shape of ${\alpha}-actinin$ from pre-rigor muscle did not differ from those of ${\alpha}-actinin$ from post-rigor muscle. On the other hand, although tropomyosin of myofibril changed negligibly during the post-mortem storage of muscle, troponin of myofibril changed remarkably.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.13 no.1
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• pp.58-66
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• 2007

The purpose of this study is to understand the structure and biomechanics of the skeletal muscle. The skeletal muscle takes 40 to 45% of the whole body. Stable posture requires a balance of muscle. However, when the muscle strength is unbalanced, movement initiates. The power generated by the muscle is a primary means to adjust the equilibrium of posture and movement. The structural unit of the skeletal muscle is a long cylindrical type muscle fiber which contains hundreds of nucleus. The thickness of muscle fiber is about $10-100{\mu}m$, and its length is about 1-50cm. Muscle fiber is composed of myofibril that is covered with plasma membrane which is called sarcolemma. In understanding the movement of human body, it is important to comprehend the movement of bone and joint and the tension of muscle. Understanding the structure and biomechanics of muscle also provides basic information on clinical treatment of patients.

• The Journal of Internal Korean Medicine
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• v.39 no.6
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• pp.1168-1180
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• 2018

Objective: As the number of sarcopenic patients worldwide is increasing, the need for the treatment of sarcopenia is increasing. Ginseng has been reported to be a major herbal supplement. We tested whether red ginseng would be effective for sarcopenia using red ginseng preparation which can be easily obtained locally in Korea. Methods: 30 rats were randomly divided into three groups: the control group (n=10) (Group C), the group with Dexamethasone -induced sarcopenia (n=10) (Group D), and the group to which red ginseng was administered group after induced sarcopenia with Dexamethasone (n=10) (Group DH). Dexamethasone was intraperitoneally administered to group D and group DH for 7 days to make sarcopenic model. After that, the red ginseng tablets prepared by Korea Ginseng Corporation were diluted in distilled water and administered orally to the DH group for 2 weeks. Body weight and grip strength were measured 8 times during the experiment. At the end of the experiment, blood was collected by cardiac puncture. In addition, the tibialis muscle was extracted, a myofibril cross section was measured by immunohistochemical staining and MyHC (myosin heavy chain) was quantified by Western blotting. Results: The ratio of the area on myofibril cross-section showed significant differences after administration of the red ginseng tablet. Conclusions: Red ginseng has a significant effect on the recovery of myofibril cross-section on sarcopenia. This experiment will be helpful for future clinical studies on drug effects in sarcopennia.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.457-462
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• 2007

Effects of sonication on water-solubilization of myofibril from breast muscle of spent hen effects investigated in this study. To evaluate effect of salt concentration and pH, salt concentration was varied with range from 0.1 to 0.8 M, and pH was varied with range from 6.0 to 8.0. Solubility, SDS-PAGE, viscosity and ATPase activity of sonicated myofibril were measured. Solubility of myofibrillar protein containing 0.1 M NaCl at pH 8.0 after sonication was above 90%. Main components of soluble protein by SDS-PAGE were myosin heavy chain and actin. That is, it indicated breaking of myofibril structure by sonication. Also, viscosity of soluble protein increased, but Ca- and Mg-ATPase activities decreased by increasing sonication time. From these results, we concluded that most of myofibrillar proteins were denatured by sonication.

• Journal of Life Science
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• v.7 no.4
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• pp.329-335
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• 1997

This study was conducted to investigate the effect of dietary fiber(DF) levels on the meat quality in colored broiler. Colored broiler were fed on containing corn-soy basal diet(DF 5%) and high level(DF 6,7 and 8%) of dietary fiber diets for 7 weeks. Dietary fiber level of diet was make up by adding some alffalfa meal. Colored broiler meats were stored at 3$\circ$ for 24hr after skaughter, and used to analyze physico-chemical properties. Proximate component, pH, shear force value, myofibril fragmentation index, water holding capacity, cooking loss, protein extractability, fatty acid composition, Hunter's L, a value and palatability of cooked meat were not significantly affected by dietary fiber levels, whereas the Hunter's value of meat was significantly affected bty dietary fiber levels for the final period of feeding. Crude protein content, myofibril fragmentation index, water holding capacity, protein extractability and Hunter's b value of breast meat's were higher than thigh meat's, but crude fat content, pH, shear force value, cooking loss, palmitoleic acid, linolenic acid, and Hunter's a value were lower, regardless of dietary fiber level.

• Applied Microscopy
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• v.50
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• pp.9.1-9.8
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• 2020

The fine structural characteristics of cardiac muscle cells and its myofibril organization in the orb web spider N. clavata were examined by transmission electron microscopy. Although myofibril striations are not remarkable as those of skeletal muscles, muscle fibers contain multiple myofibrils, abundant mitochondria, extensive sarcoplasmic reticulum and transverse tubules (T-tubules). Myofibrils are divided into distinct sarcomeres defined by Z-lines with average length of 2.0 ㎛, but the distinction between the A-band and the I-bands is not clear due to uniform striations over the length of the sarcomeres. Dyadic junction which consisted of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum is found mainly at the A-I level of sarcomere. Each cell is arranged to form multiple connections with neighboring cells through the intercalated discs. These specialized junctions include three types of intercellular junctions: gap junctions, fascia adherens and desmosomes for heart function. Our transmission electron microscopy (TEM) observations clearly show that spider's cardiac muscle contraction is controlled by neurogenic rather than myogenic mechanism since each cardiac muscle fiber is innervated by a branch of motor neuron through neuromuscular junctions.

• Food Science and Preservation
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• v.16 no.6
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• pp.875-883
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• 2009

We investigated the effects of manufacturing method on the quality of beef jerky using electron micrography. Six types of beef jerky were prepared by the addition of sugar (A), licorice (B), one of three kinds of spice extract (clove: C, fennel fruit: D, and Chungyang green pepper extract: E), or a mixture of all spice extracts (F). Microstructural changes in beef jerky during preparation by drying, with respect to drying method and the nature of the added spice extract, were observed by scanning electron micrography (SEM) and transmission electron micrography (TEM). The latter technique showed that the microstructure of fresh meat showed actin and myosin in myofibril lines, and also mitochondria and inner membranes. Beef muscle structure was broken at many myofibril lines and decomposition of inner membrane material was evident after seasoning. SEM of air-blast dried beef jerky with added medicinal herb extracts showed both large spaces and regular myofibrils, whereas hot air-dried beef jerky had no spaces and the muscle myofibrils were still evident. After review of all available micrographs from SEM and TEM, we concluded that use of medicinal herb extracts could be helpful in preserving the muscle myofibril structure during drying, and the air-blast drying method is recommended to optimize the textural quality characteristics of beef jerky.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.629-636
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• 1991

Yellowtail fishes(Seriola quinqueeradiata) were submitted to the storages using ice-cooling($0^{\circ}C$), partial freezing($-3^{\circ}C$) and freezing $-20^{\circ}C$) method. Changes in the structures of muscle during storage at different temperatures were investigated. The ice-cooling and partial freezing storage caused early decomposition of glycogen granules and mitochondrial inner membrane, but it was accorded to much slower manner comparing with that of ice-cooling storage. The scars of ice crystals were appeared after three days of storage. The number and size of the crystal increased as progressing of the storage. They were circular and mostly located between fibers. When using the freezing storage, glycogen granules were mostly found from the muscle cell even after fourteen days of storage. Mitochonidral inner membrane maintained their integrity. The scars of ice crystals were also found, however, different from those of partial freezing storage. Their existing sites were random and their shapes were irregular. In many cases, they located in the fiber and had keen edges. Fibers were broken mostly at the Z-lines on fourteen days of storage. From these results, it was concluded that partial freezing storage can repress autolytic enzymic action and can reduce the physical damage from ice crystals which is caused by freezing.