• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.757-766
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• 2019

Objective: MicroRNAs are a class of endogenous small regulatory RNAs that regulate cell proliferation, differentiation and apoptosis. Recent studies on miRNAs are mainly focused on mice, human and pig. However, the studies on miRNAs in skeletal muscle of sheep are not comprehensive. Methods: RNA-seq technology was used to perform genomic analysis of miRNAs in prenatal and postnatal skeletal muscle of sheep. Targeted genes were predicted using miRanda software and miRNA-mRNA interactions were verified by quantitative real-time polymerase chain reaction. To further investigate the function of miRNAs, candidate targeted genes were enriched for analysis using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment. Results: The results showed total of 1,086 known miRNAs and 40 new candidate miRNAs were detected in prenatal and postnatal skeletal muscle of sheep. In addition, 345 miRNAs (151 up-regulated, 94 down-regulated) were differentially expressed. Moreover, miRanda software was performed to predict targeted genes of miRNAs, resulting in a total of 2,833 predicted targets, especially miR-381 which targeted multiple muscle-related mRNAs. Furthermore, GO and KEGG pathway analysis confirmed that targeted genes of miRNAs were involved in development of skeletal muscles. Conclusion: This study supplements the miRNA database of sheep, which provides valuable information for further study of the biological function of miRNAs in sheep skeletal muscle.

• Biomedical Science Letters
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• v.18 no.3
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• pp.276-282
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• 2012

High-intensive endurance exercises induce cell changes in body, changes in structures and functions of the heart, the muscles, the cartilages, and the liver, as well as increase of inflammatory cytokine. The purpose of this study was to estimate the biochemical changes in the liver and muscles during ultra-marathon race (100 km) by sections. The blood of the subjects was collected before the marathon as a control in order to analyze serum creatine kinase (CK), lactic dehydrogenase (LDH), asprtate aminotransferase (AST), alanine aminotransferase (ALT), total(T)-bilirubin, direct(D)-bilirubin, total protein, albumin, uric acid, gamma-glutamyltranspeptidase (${\gamma}$-GTP), alkaline phosphatase (ALP), creatinine, blood urea nitrogen (BUN), and high sensitive C-reactive protein (hs-CRP) concentrations. The CK, LDH, D-bilirubin, AST and ALT concentrations at 50 km and 100 km were significantly increased compared to the control (P<0.05). The markers at 100 km were higher than those at 50 km (P<0.05). The T-bilirubin and hs-CRP concentrations showed no difference among the groups, whereas the markers at 100 km were higher than those of the control and at 50 km (P<0.05). In conclusion, this study shows that the ultra-marathon race (100 km) may induce the damage of the skeletal muscle, liver and kidney, intravascular hemolysis and inflammatory responses.

• Animal cells and systems
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• v.1 no.2
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• pp.329-335
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• 1997

The final pattern of the skeletal muscle of a vertebrate depends on the position-specific behavior of the muscle precursor cells during early developmental process and the abdominal muscle is made of cells which migrate a relatively long distance from their original tissue, myotome of dorsal mesoderm. We report the spatia-temporal migration pattern of abdominal muscle in Xenopus laevis by in situ hybridization and immunohistological studies. Shortly after hatching tadpole stage (stage 31/32), a group of myotomal cells detaches from the lower tip of the second somite and migrates ventrally to the lower position of abdomen. At stage 34/35, a second cell group migrates away from the third somite. Total 7 myotomal cell groups migrate ventrally one by one from the second to eighth myotome along their own pathways through the cell free space located between epidermis and subepidermal layer of the abdomen. During migration, the sizes of the cell groups (abdominal muscle anlagens) are increased to several tens fold. Around stage 40 all the abdominal muscle anlagens reaches their final positions and are interconnected side by side rostrocaudally. They are also connected to other types of muscles, forming a large multisegmented abdominal muscle. Heat shock study suggests that the disruption of segmentation of somites does not block the detachment of abdominal muscle anlagen, though the treatment gave stage- and dosagedependent effects on the migration speed.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.158-158
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• 2015

Myoblast are myogenic precursors that proliferate, activate, and differentiate on muscle injury to sustain the regenerative capacity of skeletal muscle; The neuronal isoform of nitric oxide synthase (nNOS, termed also NOS-I) is expressed in normal adult skeletal muscle, suggesting important functions for Nitric oxide (NO) in muscle biology1,2,3. However, the expression and subcellular localization of NO in muscle development and myoblast differentiation are largely unknown. In this study, we examined effects of the nitric oxide generated by a microwave plasma torch, on proliferation/differentiation of rat myoblastic L6 cells. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimetres per minute. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the ratio of oxygen gas, and the microwave power4. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to L6 skeletal muscles. Differentiation of L6 cells into myotubes was significantly enhanced the differentiation after nitric oxide treatment. Nitric oxide treatment also increase the expression of myogenesis marker proteins and mRNA level, such as myogenin and myosin heavy chain (MHC), as well as cyclic guanosine monophosphate (cGMP), However during the myotube differentiation we found that NO activate oxidative stress signaling erks expression. Therefore, these results establish a role of NO and cGMP in regulating myoblast differentiation and elucidate their mechanism of action, providing a direct link with oxidative stress signalling, which is a key player in myogenesis. Based on these findings, nitric oxide generated by plasma can be used as a possible activator of cell differentiation and tissue regeneration.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.160-174
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• 2023

The purpose of this study was to compare marbling score, meat quality, juiciness, sarcomere length, and skeletal muscle satellite cell (SMSC) growth and related gene expression between Woori black pig (WB) and the Landrace, Yorkshire, and Duroc (LYD) crossbreed at different body weights (b.w.). WB was developed to improve meat quality and growth efficiency by crossbreeding Duroc with Korean native black pig. A total of 24 pigs were sacrificed when their b.w. reached about 50, 75, 100, and 120 kg. SMSC were isolated from the femoris muscles, and muscle and adipose tissues were sampled from the middle and the subcutaneous part of the femoris of hind legs, respectively. Expression levels of genes including Myoblast determination protein 1 (MyoD), Paired box gene 3 (Pax3), Myosin heavy chain (MyHC), and Myogenin, which are responsible for the growth and development of SMSC, were higher in LYD than the WB. Muscle growth inhibitor myostatin (MSTN), however, was expressed more in WB compared to LYD (p < 0.01). Numbers of SMSC extracted from femoris muscle of LYD at 50, 75, 100, and 120 kg b.w. were 8.5 ± 0.223, 8.6 ± 0.245, 7.2 ± 0.249, and 10.9 ± 0.795, and those from WB were 6.2 ± 0.32, 6.2 ± 0.374, 5.3 ± 0.423, and 17.1 ± 0.315, respectively. Expression of adipogenic genes in adipose tissue including CCAAT/enhancer-binding protein (CEBP)-β, peroxisome proliferator activated receptor (PPAR)-γ, and fatty acid synthase (FASN), were greater in WB when compared with LYD (p < 0.01). Results from the current study suggest that different muscle cell numbers between 2 different breeds might be affected by related gene expression and this warrants further investigation on other growth factors regulating animal growth and development.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.100-110
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• 2003

The purpose of this article is to understand of the muscle adaptation based on myosin heavy chain. Especially, skeletal muscle dadptation in related to aging, unloading, training will discussed. MHC expression is highly plastic in muscles of adult mammals in accordance with the environmental conditions. These changes is called muscle plasticity. The plasticity is the atility of muscle cell to alter either the quantity of protein or the type of protein. MHC is both an important structural and regulatory protein comprising the contractile apparatus.

• Journal of Animal Science and Technology
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• v.61 no.5
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• pp.260-271
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• 2019

The objective of this study was to determine the effect of different stocker management programs on skeletal muscle development and growth characteristics, satellite cell (SC) activity in growing-finishing beef cattle as well as the effects of SC-conditioned media on preadipocyte gene expression and differentiation. Fall-weaned Angus steers (n = 76; $258{\pm}28kg$) were randomly assigned to 1 of 4 stocker production systems: 1) grazing dormant native range (NR) supplemented with a 40% CP cottonseed meal-based supplement ($1.02kg{\cdot}steer^{-1}{\cdot}d^{-1}$) followed by long-season summer grazing (CON, 0.46 kg/d); 2) grazing dormant NR supplemented with a ground corn and soybean meal-based supplement fed at 1% of BW followed by short-season summer grazing (CORN, 0.61 kg/d); 3) grazing winter wheat pasture (WP) at high stocking density (3.21 steers/ha) to achieve a moderate rate of gain (LGWP, 0.83 kg/d); and 4) grazing winter WP at low stocking density (0.99 steers/ha) to achieve a high rate of gain (HGWP, 1.29 kg/d). At the end of the stocker (intermediate harvest, IH) and finishing (final harvest, FH) phases, 4 steers / treatment were harvested and longissimus muscles (LM) sampled for cryohistological immunofluorescence analysis and SC culture assays. At IH, WP steers had greater LM fiber cross-sectional area than NR steers; however, at FH, the opposite was observed (p < 0.0001). At IH, CORN steers had the lowest Myf-5+:Pax7+ SC density (p = 0.020), while LGWP steers had the most Pax7+ SC (p = 0.043). At FH, CON steers had the highest LM capillary density (p = 0.003) and their cultured SC differentiated more readily than all other treatments (p = 0.017). At FH, Pax7 mRNA was more abundant in 14 d-old SC cultures from HGWP cattle (p = 0.03). Preadipocytes exposed to culture media from proliferating SC cultures from WP cattle isolated at FH had more $PPAR{\gamma}$ (p = 0.037) and less FABP4 (p = 0.030) mRNA expression compared with NR cattle. These data suggest that different stocker management strategies can impact skeletal muscle growth, SC function, and potentially impact marbling development in growing-finishing beef cattle.

• 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.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.1
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• pp.47-63
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• 2008

Objectives : Eucommiae cortex is reported that it helps bone and skeletal muscle stronger. In case of bone, many report is presented, but reports related to skeletal muscle are rarely existed. So in order to investigate effects of Eucommiae cortex on the skeletal muscle atrophy following stroke, cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) in the rats. Methods : In order to induce MCAO rats, nylon suture was advanced and then blocked middle cerebral artery(MCA). Water extract of Eucommiae cortex was treated for 15 days, once a day orally, after the MCAO. Effects were evaluated with muscle weights, muscle fiber type composition, cross-sectioned area of muscle fibers in soleus and gastrocnemius of the unaffected and affected hind limbs. And MyoD protein expression in gastrocnemius was demonstrated with immunohistochemistry and western blotting. Results : In the affected hind limb of the MCAO rats, muscle weight loss of gastrocnemius and tibialis anterior muscles were attenuated by Eucommiae cortex treatment. In soleus muscle of the affected hind limb of the MCAO rats, increase of type-I fibers and decrease of type-II fibers were induced by Eucommiae cortex treatment. In soleus muscle of the affected hind limb of the MCAO rats, decrease of cross-sectioned areas of type-I fibers was attenuated by Eucommiae cortex treatment. In gastrocnemius muscle of the affected hind limb of the MCAO rats, increase of type-I fibers and decrease of type-II fibers were induced by Eucommiae cortex treatment. In gastrocnemius muscle of the affected hind limb of the MCAO rats, decreases of cross-sectioned areas of type-I and type-II fibers were attenuated by Eucommiae cortex treatment. In gastrocnemius muscle of the affected and unaffected hind limb of the MCAO rats, MyoD expressions were increased by Eucommiae cortex treatment. Conclusions : These results suggest that Eucommiae cortex has a protective effect against muscle atrophy, through the inhibition of the muscle cell apoptosis, following the central nervous system demage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1356-1362
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• 2005

The purpose of this study os to investigative the effect of Carrageenan-Induced Pain on lower limb muscle and ligament of rat. To evaluate pain mechanism in muscle and ligament, pain was induced by the injection of 2% $0.1m{\ell}$ carrageenan into the left lower limb muscle of rats after rats were anesthesized with 3% enflurane. Rats were killed on 72 hours after pain induction under the anesthesia. anterior rectus femoris muscle and its ligament were removed from rat hind limb. Morphological changes of them were peformed by the observation of light and electron microscopes. In the light microscopic findings, the muscle cells were polyheadral and situated with each other without small gap in control group. nucleus of cell was seen along the cell margin, and muscle cell groups were divided by regular narrow gap in cross section. In the pain-induced group, muscle cell groups were divided each other by the irregular gap, and some of groups formed larger than other cell groups by the fusion. Intercellular gap of most cell groups were increased compared with control groups. And also, perimysium of muscle cell groups was swollen in cross section. In control group, muscle cells contacted each other closely and each cell was divided by perimysium. The intracellular gaps were not seen between myofibrills, and also striations were well defined between muscle cells in longitudinal section. In pain-induced group, muscle cells were divided by the small intracellular gaps. And also, muscle cell showed many a short cross or longitudinal intercellular gaps in longitudinal section. In light microscopic findings of control group, tendon was composed with many tendon fibers contacted each other closely without gap. The free margin of tendon was fused, and apso the tendon fibers did not invaded between muscles. In pain-induced group, tendon was divided small groups by intertendinous gap, and also the margin of tendon divided by small groups. In the free margin, tendon invaded into muscle cells, and also fibroblasts between tendon fibers were long and lance-shaped. From these results, it is suggested that pain induction by carrageenan injured rat skeletal muscle and ligament by the morphological changes.