• 농업과학연구
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• 제44권4호
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• pp.586-594
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• 2017

Mitochondrial activity affects skeletal muscle energy metabolism and phenotype. To address whether mitochondrial activity can modulate muscle phenotype in vitro, protein expression of myosin heavy chain (MyHC) in C2C12 muscle cell lines was investigated after treated with antimycin A, an inhibitor of oxidative phosphorylation in mitochondria. Fully differentiated C2C12 myotubes were administrated with different concentration of antimycin A including 0, 100, 200, 500, 700, and 1000 ng/mL. After 72 h treatment, myosin heavy chain isoform expression and related enzyme activity (lactate dehydrogenase; LDH and creatine kinase) were analyzed. Administration of antimycin A changed expression of MyHC in C2C12 myotubes showing a shift from slow to fast twitching muscle type. Protein expression of MyHC type 2b (fast twitching muscle type) was decreased (P < 0.05) by antimycin A treatment (500, 700, and 1000 ng/mL) when compared with control group. Administration of antimycin A (1000 ng/mL), however, decreased (P < 0.05) MyHC type I (slow twitching muscle type). Interestingly, LDH activity was increased (P < 0.05) by antimycin A treatment. Results from our current study proposed a possibility that skeletal muscle phenotype, including MyHC and LDH activity, can be shifted from slow to fast twitching type by inhibiting the mitochondrial activity in C2C12 myotubes.

• Journal of the Optical Society of Korea
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• 제18권1호
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• pp.55-59
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• 2014

Sarcopenia, or reduced muscle mass and volume, is due to various factors such as senile change, neuronal degeneration, drug, malignancy, and sepsis. Sarcopenia with the aging process has been evidenced by the decline in muscle mass by 0.5 to 1% per year with 3-5% reduction in muscle strength for 10 years between the ages of 40 and 50, and a 1-2% of decline of mass every year in people aged 60-70. Therefore, early diagnosis and understanding the mechanism of sarcopenia are crucial in the prevention of muscle loss. However, it is still difficult to image changes of muscle microstructure due to a lack of techniques. In this study, we developed an animal model using denervated rats to induce a rapid atrophy in the tibialis anterior (TA) and imaged its structural changes using optical coherence tomography (OCT) along with histologic and ultrasound analyses. Ultrasound showed changes of overall muscle size. Histology revealed that the atrophic TA muscle displayed an increased size variability of muscle fiber and inflammatory changes. Three dimensional OCT imaged the changes of perimysial grid and muscle fiber structure in real time without sacrifice. These observed advantages of multimodal imaging using OCT and ultrasound would provide clinical benefits in the diagnosis of sarcopenia.

• 한국식품영양과학회지
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• 제22권6호
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• pp.763-770
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• 1993

To investigate the quality changes during frozen storage, top shell, Omphalius pfeifferi capenteri, was stored at -18$^{\circ}C$, -$25^{\circ}C$ and -3$0^{\circ}C$ immediately after shelling and water holding capacity, protein composition and histological features were examined with the lapsed period of the storage. During the storage period, amount of free drip was increased with higher frozen temperature and longer frozen period, but with the longer storage period, the lower water holding capacity was observed. The extractability and composition of muscle protein, sarcoplasmic protein and stroma protein were rather stable regardless of frozen temperature and frozen storage period. However, the extractability of myofibrillar protein was decreased with higher frozen temperature and longer frozen storage period. On the changes of muscle tissue structure, following points were observed. 1) In the muscle tissue structure of fresh sample, fine muscle fiber was closely distributed all over the tissue regardless of cross and longitudinal section. 2) In tissue structure under frozen state, it was observed that ice crystals apparently grew with the higher storage temperature. Empty spaces between muscle bundles which wee formed by aggregations of muscle fiber were observed after 3 months storage at -18$^{\circ}C$ . 3) Tissue structure in thawed state was restored satisfactorily after 1 month storage regardless of storage temperature. After 3 months storage at -3$0^{\circ}C$, muscle tissue was well restored, but at -18$^{\circ}C$, empty spaces were apparent due to incomplete restoration.

• 대한통합의학회지
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• 제7권2호
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• pp.121-131
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• 2019

Purpose : Lower back pain is a common disorder experienced by approximately 90-% of the population at least once in a lifetime. This study examines changes in the thicknesses and ratios of the deep and superficial fibers of the multifidus according to the lumbar stabilization exercise used for spinal stabilization. Methods : Ten different lumbar stabilization exercises were implemented by 20 healthy men in random order, and the thickness of multifidus muscle was measured ultrasound image during each exercise. Results : The surface muscle fibers of the multifidus muscles significantly increased in the exercise method in which the arms and legs were lifted (p<.05), while the deep muscle fibers of the multifidus muscles increased significantly in the exercise in which the arms and legs were not lifted (p<.05). The ratio of the thickness of surface muscle fibers to the total thickness of muscle fibers was higher in the exercise method in which the arms and legs were lifted (p<.05), while the ratio of the thickness of deep muscle fibers to the total thickness of muscle fibers was higher in the hollowing and bracing exercise method in which the arms and legs were not lifted (p<.05). Conclusion : When lumbar stabilization exercise should be performed at clinics to strengthen the deep muscle fibers of the multifidus muscles that have larger effects on the stability of spinal segments, taking the stability of the spine into consideration indicates that, hollowing and bracing exercise methods that do not that cause isotonic extension to the spine are appropriate.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1430-1438
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• 2019

Objective: This experiment was designed to determine the effects of coated cysteamine hydrochloride (CC) on muscle fiber characteristics, amino acid composition and transporters gene expression in the longissimus dorsi muscle (LDM) of finishing pigs. Methods: Two hundred and sixteen Duroc/Landrace/Yorkshire cross-bred male finishing pigs were fed with a corn-soybean basal diet supplemented with 0, 70, and 140 mg/kg cysteamine. Each group contained eight replicates of nine pigs per replicate. After 29 days, one pig was randomly selected from each replicate and slaughtered. Blood and LDM samples were collected and analyzed. Results: The results showed that supplemental dietary CC increased (p<0.05) the muscle fiber density. And CC supplementation also up-regulated (p<0.05) the expression of myosin heavy chain 1 (MyHC1) and MyHC2x mRNA levels, and down-regulated (p<0.05) MyHC2b expression in the LDM. Additionally, supplemental dietary CC reduced (p<0.05) the concentration of total cholesterol in the plasma and enhanced (p<0.05) the concentrations of essential amino acid and total amino acid in the LDM. The relative expression levels of chloramphenicol acetyltransferase 2, $b^{0,+}$ amino acid transporter, and $y^+$-L-type amino acid transporter 1 were upregulated (p<0.05) in the LDM when pigs were fed with the dietary CC of 70 mg/kg. Conclusion: Cysteamine supplementation could increase fiber density and distribution of fiber types. It also improved the deposition of protein in the LDM by up-regulated the expression of amino acid transporters.

• Journal of Acupuncture Research
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• 제18권1호
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• pp.170-185
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• 2001

Objective : This experimental study was designed to investigate the effect of Chaenomelis fructus herbal acupuncture on the soleus muscle and tibialis anterior muscle of hindlimb-suspended rats. The measurement have been performed on the composition of type I, type IIa and type IIb muscle fibers in the soleus muscle and tibialis anterior muscie - histochemical study. Materials and Methods : Sprague-Dawley rats weighing about 250g were subjected to hindlimb suspension and divided into six groups; 1. Normal group: normai group 2. Control group: group of hindlimb suspension for 7 days 3. NT group: non-treatment group for 2 or 4 weeks after 7days of hindlimb suspension. 4. EX gtoup: running exercise group for 2 or 4 weeks after 7days of hindlimb suspension. 5. HA group: administration of Chaenomelis fructus herbal acupuncture during 2 or 4 weeks after 7 days of hindlimb suspension. 6. EXHA group: administration of Chaenomelis fructus herbal acupuncture and running exercise during 2 or 4 weeks after 7 days of hindlimb suspension. Results Results : 1. The composition of type I muscle fibers in the soleus muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the composition of type IIa muscle fibers in the soleus muscle significantly decreased in 2 or 4 weeks HA and EXHA goups more than control group. 2. The composition of type I muscie fibers in the tibialis anterior muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the composition of type IIb muscle fibers in the soleus muscle significantly decreased in 2 or 4 weeks HA and EXHA groups more than control group. 3. The size of type I muscle fibers in the soleus muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the size of type IIa muscle fibers in the soleus muscle significantly increased in 2 weeks EXHA group and 4 weeks HA and EXHA groups more than control group. 4. The size of type I, IIa muscle fibers in the tibialis anterior muscle significantly increased in 2 or 4weeks HA, EXHA and EX groups more than control group, and the size of type IIb muscle fibers significantly increased in 2 weeks EXHA group and 4 weeks HA, EXHA and EX groups more than control group. 5. The capiliaries number per fiber of muscle fibers in the soleus and tibialis anterior muscle showed no differences in all experimental groups more than control group. Conclusion : According to the above results, it is shown that Chaenomelis fructus herbal acupuncture could be effective in the treatment of muscle atrophy.

• The Korean Journal of Physiology
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• 제4권2호
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• The Journal of Korean Physical Therapy
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• 제18권3호
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• pp.59-70
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• 2006

Purpose: This study is intended to examine the aquatic exercise on the improvement of muscle atrophy and motor function in an ischemic stroke model induced by middle cerebral artery occlusion. Methods: We used 60 Sprague-Dawely rats which were divided into 4 groups; the subjects were divided into group of 5 rats. Group I was a group of high dose aquatic exercise after inducing ischemic stroke; Group II was a group of low dose aquatic exercise after inducing ischemic stroke; Group III was a control group, Group IV was a sham group without ischemic stroke. Results: Muscle weight of gastrocnemius muscle was significantly difference in Group II compared to Group III on 8 weeks(p<0.05). For the changes in relative muscle weight of gastrocnemius muscle, there was significant increase in Group II compared to Group III on 8 weeks(p<0.05). For neurologic exercise behavior test, Group II generally had the highest score, compared to other groups. The results of behavior test that Group II improved in degeneration and inflammation of muscle fiber and decreased in destruction of nerve cells and cerebral infarction, indicating a similar state of muscle fiber and brain to Group III. Conclusion: Based on these results, aquatic exercise may improve muscle atrophy and contribute to the improvement of motor function.

• 한국전문물리치료학회지
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• 제13권1호
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• pp.38-46
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• 2006

The purposes of this study were to investigate the median frequency (MDF) between initiation and termination of muscle contraction through surface electromyographic (sEMG) analysis and to propose the basis of clinical treatment for movement problems in early hemiparetic upper limbs. Thirteen patients who had stroke with onset less than 3 months prior to the study and seven control subjects participated in the study. The median frequency in initiation and termination of muscle contraction was recorded from wrist flexor and extensor muscles using the sEMG, with 3 second beeper signals, during maximal isometric wrist flexion and extension. Flexion and extension must be done as quickly and forcefully as possible. The results of the study were as follows: 1. The MDF of the onset and offset sections were significantly lower on the paretic than the nonparetic and control sides. 2. The MDF of the offset section significantly decreased on the paretic and nonparetic sides. Consequently, this study showed that the lowering of the MDF was due to the hemiparetic wrist motor impairment and muscle weakness. These results are also related to Fugl-Meyer motor assessment (FMA) scores in hemiparetic upper limbs. This study also suggests that since muscle weakness of early stroke patients affects the functional decrease of upper limbs, further studies must focus on the treatment to improve muscle agility and muscle fiber recruitment efficiency that can induce the functional recovery correlated to motor control.

• BMB Reports
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• 제52권1호
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• pp.64-69
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• 2019

The loss of skeletal muscle, called sarcopenia, is an inevitable event during the aging process, and significantly impacts quality of life. Autophagy is known to reduce muscle atrophy caused by dysfunctional organelles, even though the molecular mechanism remains unclear. Here, we have discuss the current understanding of exercise-induced autophagy activation in skeletal muscle regeneration and remodeling, leading to sarcopenia intervention. With aging, dysregulation of autophagy flux inhibits lysosomal storage processes involved in muscle biogenesis. AMPK-ULK1 and the $FoxO/PGC-1{\alpha}$ signaling pathways play a critical role in the induction of autophagy machinery in skeletal muscle, thus these pathways could be targets for therapeutics development. Autophagy has been also shown to be a critical regulator of stem cell fate, which determines satellite cell differentiation into muscle fiber, thereby increasing muscle mass. This review aims to provide a comprehensive understanding of the physiological role of autophagy in skeletal muscle aging and sarcopenia.