• BMB Reports
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• v.54 no.11
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• pp.575-580
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• 2021

Cisplatin is widely known as an anti-cancer drug. However, the effects of cisplatin on mitochondrial function and autophagy-related proteins levels in the skeletal muscle are unclear. The purpose of this study was to investigate the effect of different doses of cisplatin on mitochondrial function and autophagy-related protein levels in the skeletal muscle of rats. Eight-week-old male Wistar rats (n = 24) were assigned to one of three groups; the first group was administered a saline placebo (CON, n = 10), and the second and third groups were given 0.1 mg/kg body weight (BW) (n = 6), and 0.5 mg/kg BW (n = 8) of cisplatin, respectively. The group that had been administered 0.5 mg cisplatin exhibited a reduced BW, skeletal muscle tissue weight, and mitochondrial function and upregulated levels of autophagy-related proteins, including LC3II, Beclin 1, and BNIP3. Moreover, this group had a high LC3 II/I ratio in the skeletal muscle; i.e., the administration of a high dose of cisplatin decreased the muscle mass and mitochondrial function and increased the levels of autophagy-related proteins. These results, thus, suggest that reducing mitochondrial dysfunction and autophagy pathways may be important for preventing skeletal muscle atrophy following cisplatin administration.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.1
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• pp.31-43
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• 2003

The present studies are designed to determine whether the NMES can affect the muscle atrophy in rats following administration of steroid. Rats were divided into four groups: 1) Control group treated with administration of distilled water. 2) The group treated with administration of steroid. 3) The group treated with NMES once a day after adminstration of steroid. 4) The group treated with NMES twice a day after administration of steroid. The muscle atrophy was induced by one week administration of dexamethasone once a day by 3 mg/kg. The change in the structure of muscle fiber and the amount. of myofibril protein and gastrocnemius were determined after every week dissection of the tissues. The results were as follows; 1. The administration of steroid significantly affected the decrease in the weight, but NMES did not affect the inhibition of decrease in the weight. 2. The weight of gastrocnemius in the group once treated with NMES was changed two weeks later; similarly in the group twice treated with NMES significantly did two or three weeks later. These indicated that NMES affected the muscular activation of gastrocnemius(p<.05). 3. The changes in the amount of gastrocnemius protein by NMES might, indicate that NMES activated the capacity of synthesis of muscle fiber protein(p<.05).

• Journal of Life Science
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• v.24 no.9
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• pp.1019-1024
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• 2014

Skeletal muscle atrophy can be defined as a decrease in or a disease of the muscle tissue, or as a disorder of the nerves that control the muscle, through injury or lack of use. This condition is associated with reactive oxygen species (ROS), resulting in various muscular disorders. Exposure to ROS induces muscle atrophy through several biological factors, such as SOD1 and HSP70. We found that cymbidium root extract reduced the $H_2O_2$-induced viability loss in C2C12 myoblasts and inhibited apoptosis. In addition, we showed that the cymbidium root extract increased the expression of HSP70 and decreased the expression of SOD1 in the $H_2O_2$-induced C2C12 myoblasts. These results suggest that cymbidium root extract might have therapeutic value in reducing ROS-induced muscle atrophy.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.159-168
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• 2008

Objectives : The present study has been undertaken to investigate the effects of Dipsaci Radix on Muscle Fiber Atrophy and MyoD Expression in Gastrocnemius of MCAO Rats Methods : In order to investigate effects of Dipsaci radix on the skeletal muscle atrophy following stroke, cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) in the rats. Water extract of Dipsaci radix (184.4 mg/100 g) was treated for 4 weeks, once a day orally, after the MCAO. Effects were evaluated with muscle fiber type composition and cross-sectioned area of muscle fibers in gastrocnemius of the unaffected & affected hind limbs. And MyoD protein expression in gastrocnemius was demonstrated with immunohistochemistry and western blotting. Results : Obtained results were as follows; 1. Infarct volume was not attenuated by Dipsaci radix treatment in the MCAO rats. 2. At the affected-side hind limb of the MCAO rats, the increase of type-I fibers and the decrease of type-II fibers were induced by Dipsaci radix treatment. 3. At the affected-side hind limb of the MCAO rats, decreases of cross-sectioned areas of type-I and type-II fibers were attenuated by Dipsaci radix treatment. 4. At the affected-side hind limb of the MCAO rats, MyoD positive cells were increased by Dipsaci radix treatment. 5. At the affected-side hind limb of the MCAO rats, MyoD expressions were increased by Dipsaci radix treatment. Conclusions : These results suggest that Dipsaci radix has a protective effect against muscle atrophy, through the inhibition of the muscle cell apoptosis, following the central nervous system demage.

• Osteoporosis and Sarcopenia
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• v.3 no.3
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• pp.117-122
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• 2017

Sarcopenia is the degenerative loss of muscle mass and function with aging. Recently sarcopenia was recognized as a clinical disease by the International Classification of Disease, 10th revision, Clinical Modification. An imbalance between protein synthesis and degradation causes a gradual loss of muscle mass, resulting in a decline of muscle function as a progress of sarcopenia. Many mechanisms involved in the onset of sarcopenia include age-related factors as well as activity-, disease-, and nutrition-related factors. The stage of sarcopenia reflecting the severity of conditions assists clinical management of sarcopenia. It is important that systemic descriptions of the disease conditions include age, sex, and other environmental risk factors as well as levels of physical function. To develop a new therapeutic intervention needed is the detailed understanding of molecular and cellular mechanisms by which apoptosis, autophagy, atrophy, and hypertrophy occur in the muscle stem cells, myotubes, and/or neuromuscular junction. The new strategy to managing sarcopenia will be signal-modulating small molecules, natural compounds, repurposing of old drugs, and muscle-specific microRNAs.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.16-44
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• 2003

Skeletal muscle regeneration is a vital process for various muscle myopathies and muscular adaptation to physiological overload. Angiogenesis is the key event in the process of muscle regeneration, and vascular endothelial growth factor(VEGF) plays an important role in it. The purpose of this study was to evaluate the effect of GaAlAs(830nm) laser and immunoreactivity of VEGF on angiogenesis after muscle contusion injury. Muscle contusion injury was induced in the triceps surae muscle by dropping a metal bead(31.4g). GaAlAs laser irradiation(power 20 mW, frequency 2000 Hz, treatment time 15 min) was applied directly to the skin of injured muscle daily for seven days. The experimental group I was irradiated immediately by laser after injury, whereas the experimental group II was irradiated after 1 day of injury. The control group was non-irradiated. The results of this study were as follows. 1. In morphological observation, there were no significant changes in experimental and control groups for 7 days. At 3 days, however, the splited muscle fibers were observed in experimental groups, and the muscle atrophy and granular tissue viewed at 7 days in control group. 2. The VEGF was expressed in muscle fiber that located in the interspace between gastrocnemius and soleus muscles. As the time coursed, the immunoreactivity of VEGF also seemed to be strong in the individual muscle fibers. 3. The experimental group I & II showed higher immunoreactivity of VEGF than control group(p<0.05). Then, the experimental group I showed higher than group II especially(p<0.05). These data suggest GaAlAs semiconduct diode laser irradiation(830nm) enhanced angiogenesis in the skeletal muscle induced contusion injury, and immediate laser irradiation after injury promoted the angiogenesis greatly than after 1 day of injury.

• The Journal of Korean Physical Therapy
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• v.19 no.3
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• pp.19-30
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• 2007

Purpose: This study was performed to investigate the effects of NMES for recovery of skeletal muscle. Methods: The normal group consisted of healthy rat without cast immobilization. The control group was breeding at standard cage during 7 days after 2 weeks-cast immobilization on hind limb. The experimental group. I. received NMES application during days after 2 weeks-cast immobilization on hind limb. The effects were measured with NT-3 immunoreactivity in neuromuscular junction by light microscope. Results: Immunoreactivity of NT-3 at the neuromuscular junction was higher appeared experimental groups than control group. Then, There was a little detection in the normal and control group. Conclusion: These therapeutic interventions enhance expression of NT-3 at the neuromuscular junction. Also, NMES is considered to effect on a normal structural formation and NT-3 expression at the neuromuscular junction.

• Physical Therapy Korea
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• v.13 no.2
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• pp.9-15
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• 2006

Skeletal muscle injury occurs frequently in sports medicine and is the most general form of injury followed by physical impact. There are growth factors which conduct proliferation, differentiation, and synthesis of myogenic prodromal cells and regulate vascular generation for the continued survival of myocytes. The purpose of the present study was to confirm the effects of electroacupuncture (EA) and electrical stimulation (ES) on muscle recovery processes according to vascular endothelial growth factor (VEGF) expression. Eighteen Sprague-Dawley rats were separated into 2 experimental groups and a controlled group. All animals had suffered from crush damage in the extensor digitorum longus for 30 seconds and were killed 1, 3, and 7 days after injury. 30 Hz and 1 mA impulsion for 15 minutes was applied to the EA experimental groups Zusanli (ST36) and Taichong (LR3) using electroacupuncture and the same stimulation was applied to the ES group using an electrical node. Hematoxyline-Eosin staining and VEGF immunohistochemistry were used to ascertain the resulting muscle recovery. There were few morphological differences between the EA and ES groups, and both groups were observed to have tendencies to decrease atrophy as time passed. In the controlled group, gradually diminishing atrophy could be observed, but their forms were mostly disheveled. There were few differences in VEGF expression between the EA and ES groups, and tendencies to have an increased quantity of VEGF with the lapse of time were observed in both groups. In the controlled group, a little VEGF expression could be observed merely 7 days after injury. In conclusion, EA and ES contributed to muscle recovery processes and could be used for the treatment of muscle injury.

• Journal of Life Science
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• v.22 no.4
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• pp.447-455
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• 2012

Akt plays an important role in a variety of cellular physiologies such as growth, proliferation, and differentiation. In skeletal muscle, Akt has been implicated in regulating regeneration, hypertrophy, and atrophy. In this study, the role of Akt has been examined during skeletal muscle differentiation. Culturing C2C12 myoblasts under low serum (1% horse serum) and high density converted cell morphology from a round shape to an elongated and multi-nucleated shape. Morphological changes were initiated from day 2 of differentiation. In addition, the expression of both myogenin G and myogenin D was elevated from day 2 of differentiation. Skeletal muscle differentiation was abolished by silencing Akt1 or Akt2, but was significantly enhanced by the over-expression of either Akt1 or Akt2. The activation of Akt was observed from day 2 of differentiation and disappeared after day 7. The expression of kruppel-like factor 4 was observed from day 6 of differentiation. Moreover, this expression was blocked in cells silencing either Akt1 or Akt2. In addition, the promoter activity of kruppel-like factor 4 was significantly reduced in cells silencing Akt1 or Akt2. These results suggest that Akt regulates skeletal muscle differentiation through the regulation of kruppel-like factor 4 expression.

• Journal of Biomedical Engineering Research
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• v.27 no.2
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• pp.73-77
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• 2006

Prolonged immobilization leads to significant weakness and atrophy of the skeletal muscle and can also impair the recovery of muscle strength following injury. Therefore, it is important to minimize the period under immobilization and accelerate the return to normal activity. This study examined the effects of combined heat treatment and rest-inserted exercise on the muscle activity of the lower limb during knee flexion/extension. Twelve healthy subjects were assigned to 4 groups that included: (1) heat treatment + rest-inserted exercise; (2) heat treatment + continuous exercise; (3) no heat treatment + rest-inserted exercise; and (4) no heat treatment + continuous exercise. Heat treatment was applied for 15 mins prior to exercise. Continuous exercise groups performed knee flexion/extension at 0.5 Hz for 300 cycles without rest whereas rest-inserted exercise groups performed the same exercise but with 2 mins rest inserted every 60 cycles of continuous exercise. Changes in the rectus femoris and hamstring muscle activities were assessed at 0 and 2 weeks of treatment by measuring the electromyography signals of isokinetic maximum voluntary contraction. Significant increases in both the rectus femoris and hamstring muscles were observed after only 2 weeks of treatment when both heat treatment and rest-inserted exercise were performed. These results suggest that combination of various treatment techniques, such as heat treatment and rest-inserted exercise, may accelerate the recovery of muscle strength following injury or immobilization.