• 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.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.296-301
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• 1987

Polyamines of Korean red ginseng were extracted with 5% trichloroacetic acid and purified by ion exchange chromatography using Dowex-50Wx8 resin. Four spots having R$_f$ values of 0.19, 0.28, 0.35, and 0.45 were detected. It was observed under microscopy that those polyamines stimulated the growth and differentiation of chicken embryonic muscle cell. The development of muscle cells from the stage of myoblast to that of myotube was found to be enhanced by those polyamines. It was also observed that those polyamines most likely lengthened, the life-span of the cultured chicken embryonic skeletal muscle cells.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.248.1-248.1
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• 2002

It has been shown that C2-ceramide (C2), short chain ceramide, plays a role in mediating contraction of cat esophageal smooth muscle cells. We examined the effect of newly synthesized ceramide analogues on the C2-ceramide induced contraction in esophageal smooth muscle cells isolated with collagenase. C2-ceramide produced contraction of smooth muscle cells in a dose dependent manner. (omitted)

• 한국체육학회지인문사회과학편
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• v.54 no.5
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• pp.769-780
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• 2015

This study investigated the changes in inflammatory mediators, immunocompetent cells and bone merrow progenitor cells by the magnitude of muscle damage and type of the muscle contraction in the elderly. Twenty older adults who had not been involved in a resistance-training program at least 6 months prior to the present study were assigned to eccentric exercise group (ECC, n=10) and concentric exercise group (CON, n=10). All subjects performed 10 sets of 6 maximal isokinetic eccentric (ECC 1) or concentric (CON) contractions with the non-dominant arm in a randomized, with 4 wk between bouts (ECC 2). Skeletal muscle damage index (ROM, VAS, Plasma CK), inflammation mediators (TNF-α, IL-1, IL-6), immunocomperent cells (CD3+, CD4+, CD8+, CD19+), bone merrow progenitor cell (CD34+) and leukocytes were measured before, immediately after, 2, 24, 48, 72, and 96 h after exercise. Changes in ROM and VAS were greater (P<.05) after ECC 1 than CON and ECC 2. Increases in TNF-α and IL-6 were greater (P<.05) 24, 48 and 72 h after ECC 1 than CON and ECC 2. Increases in neutrophils were greater (P<.05) 2 h after ECC 1 than CON and ECC 2. It was confirmed that muscle damage was greater following eccentric than concentric contractions as well as first bout than second bout in the elderly, and suggested that TNF-α, IL-6 and neutrophils should closely correlate with magnitude of muscle damage.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.87-94
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• 2018

Background: Popeye deformity is common after rupture of the biceps muscle's long head tendon. Herein, we report on histological changes in biceps brachii muscles following tenotomy of the long head biceps tendon. Methods: Twelve Sprague-Dawley rats (12-week-old) underwent tenotomy of the long head biceps tendon in the right shoulder. At postoperative weeks 4, 7, and 10, the operative shoulders were removed by detaching the biceps brachii muscle from the glenoid scapula and humerus; the opposite shoulders were removed as controls. H&E staining was performed to elucidate histological changes in myocytes. Oil-red O staining was performed to determine fatty infiltration. Myostatin antibody immunohistochemistry staining was performed as myostatin is expressed by skeletal muscle cells during myogenesis. Results: H&E staining results revealed no changes in muscle cell nuclei. There were no adipocytes detected. Compared with that of the control biceps, the cross-sectional area of the long head biceps was significantly smaller (p=0.00). Statistical changes in the total extent of the 100 muscle cells were significant (p=0.00). Oil-red O staining revealed no fatty infiltration. Myostatin antibody immunohistochemical staining revealed no significant difference between the two sides. Conclusions: Muscular changes after tenotomy of the long head biceps included a decrease in the size of the individual muscle cells and in relative muscle mass. There were no changes observed in muscle cell nuclei and no fatty infiltration. Moreover, there were no changes detected by myostatin antibody immunohistochemistry assay.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.101-108
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• 2018

Objectives : This study aimed to effects antioxidant activity of citrus peel extract (CPE) and effect on its glucose metabolism in L6 rat skeletal muscle cells. Methods : Antioxidative activities were evaluated by using 10 kinds of natural materials, and total polyphenol and flavonoid contents were examined. The L6 muscle cells toxicity of CPE was examined by MTT assay. Expression of glucose-related genes in L6 muscle cells by CPE treatment was analyzed by real-time PCR and western blotting. Results : The $IC_{50}$ values of DPPH and ABTS free radical scavenging activity of CPE were ($15.47{\pm}0.26{\mu}g/m{\ell}$ and $12.07{\pm}1.23{\mu}g/m{\ell}$, respectively), effectively clearing DPPH and ABTS. CPE showed total polyphenol and flavonoid contents ($20.30{\pm}0.38$ and $64.20{\pm}0.52$, respectively). The selected CPE were used in experiments using an effective concentration that is not toxic in L6 muscle cells. We investigated insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase regulatory (PI3KR), Akt, and glucose transporter 4 (GLUT4). mRNA analysis by realtime PCR showed no significant difference, but CPE-treated cells showed a tendency to increase in concentration-dependent manner. However, analysis of protein expression of Akt and GLUT4 by western blotting showed that CPE treatment significantly increased concentration dependent (p<0.001). Conclusions : As a result, citrus peel extract with high antioxidant activity regulates glucose metabolism in L6 muscle cells. Therefore, CPE can be a potential treatment for the treatment of diabetes.

• The Journal of Korean Medicine
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• v.28 no.2 s.70
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• pp.54-65
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• 2007

Objectives : In the present study, the author investigated whether Naenghyo-hwan(NHH) significantly affect mucin secretion from airway epithelial cells. Methods : Confluent hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of NHH to assess the effect of the agent on 3H-mucin secretion. Total elutionprofiles of control spent media and treatment sample through Sepharose CL-4B column were analysed. Effect of NHH on contractility of isolated tracheal smooth muscle was investigated. Also, effect of the agent on MUC5AC gene expression in cultured NCI-H292cells was investigated. Possible cytotoxicities of the agent were assessed by measuring both lactate dehydrogenase (LDH) release from HTSE cells and examining the rate of survival and proliferation of NCI-H292 cells. Results : NHH significantly increased mucin secretion from cultured HTSE cells, with significant cytotoxicity. NHH chiefly affected the 'mucin' secretion. NHH inhibited ACh-induced contraction of isolated tracheal smooth muscle. NHH disturbed both the extraction of total RNA from NCI-H292 cells and polymerase chain reaction, nonspecifically. Therefore, in this experiment, theeffect of NHH on the expression levels of MUC 5AC gene in cultured NCI-H292 cells could not be elucidated. Conclusions : The author suggests that the effect of NHH with their components should be further investigated and it is valuable to find, from oriental medical prescriptions, novel agents which might regulate mucin secretion from airway epithelial cells.

• Animal Bioscience
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• v.34 no.1
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• pp.134-142
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• 2021

Objective: To understand the athletic characteristics of Thoroughbreds, high-throughput analysis has been conducted using horse muscle tissue. However, an in vitro system has been lacking for studying and validating genes from in silico data. The aim of this study is to validate genes from differentially expressed genes (DEGs) of our previous RNA-sequencing data in vitro. Also, we investigated the effects of exercise-induced stress including heat, oxidative, hypoxic and cortisol stress on horse skeletal muscle derived cells with the top six upregulated genes of DEGs. Methods: Enriched pathway analysis was conducted using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool with upregulated genes in horse skeletal muscle tissue after exercise. Among the candidates, the top six genes were analysed through geneMANIA to investigate gene networks. Muscle cells derived from neonatal horse skeletal tissue were maintained and subjected to exercise-related stressors. Transcriptional changes in the top six genes followed by stressors were investigated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: The inflammation response pathway was the most commonly upregulated pathway after horse exercise. Under non-cytotoxic conditions of exercise-related stressors, the transcriptional response of the top six genes was different among types of stress. Oxidative stress yielded the most similar expression pattern to DEGs. Conclusion: Our results indicate that transcriptional change after horse exercise in skeletal muscle tissue strongly relates to stress response. The qRT-PCR results showed that stressors contribute differently to the transcriptional regulation. These results would be valuable information to understand horse exercise in the stress aspect.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.4
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• pp.411-416
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• 2014

Simple formulas (單方) of muscle section in Donguibogam (東醫寶鑑) have long been prescribed for strengthening muscle and/or prevention of age-related muscle loss. However, biological activity and mechanisms by which they influence myoblast differentiation have not been studied. Therefore, in this study, we evaluated the effects of 14 simple formulas on myoblast differentiation in C2C12 myoblast cells under non-cytotoxic ($0.5mg/m{\ell}$) conditions. C2C12 cells were treated with water extracts of simple formulas for 72 h, and RT-PCR was performed to determine the gene expression levels of myogenic regulatory factors (MRFs), including myoD, myogenin, MRF4, myf5, and insulin like growth factor-1 (IGF-1). Treatment with Colocasiae Rhizoma (CR), Pini Semen (PS), and Sesami Semen (SS) resulted in a significant increase in expression of myogenin in C2C12 cells. Treatment with Allii Macrostemi Bulbus (AM), Colocasiae Rhizoma (CR), and Pini Semen (PS) also resulted in increased expression of MRF4 in C2C12 cells. In addition, enhanced expression of IGF-1 was observed in treatment with Eucommiae cortex (EC), Dioscoreae Rhizoma (DR), Colocasiae Rhizoma (CR), Pini Semen (PS), and Sesami Semen (SS) in C2C12 cells. These results indicate that simple formulas of muscle section in Donguibogam could potentially enhance myoblast differentiation at least in part via increasing expression of myogenin, and/or MRF4 and/or IGF-1.

• Journal of Life Science
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• v.33 no.9
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• pp.724-729
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• 2023

In this experiment, we aimed to investigate the role of copper in regulating the biosynthesis of a myokine called apelin in mammalian skeletal muscle cells. Our approach involved culturing skeletal muscle cells and subjecting them to treatments with copper sulfate or a copper chelator known as bathocuproinedisulfonic acid (BCS). We employed standard techniques, such as reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, to assess the synthesis of apelin at different stages, including transcription, translation, and post-translational modifications. Our findings demonstrated that copper had an inhibitory effect on apelin biosynthesis at all three stages: transcription, translation, and post-translation. However, when we treated the cells with BCS, the biosynthesis of apelin was restored to its original state. This finding suggests that copper is required for the synthesis of apelin in mammalian skeletal muscle cells. This study represents the first documented evidence of the inorganic copper-dependent regulation of apelin biosynthesis, shedding light on potential strategies for the prevention and treatment of sarcopenia induced by copper imbalances.