• Journal of Nutrition and Health
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• 제54권6호
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• pp.594-602
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• 2021

본 연구는 고지방식이로 유도한 비만 동물모델에서 아연의 식이를 통한 보충 급여가 혈당 조절과 골격 근육의 ZIP7의 작용에 미치는 영향에 대해 살펴보았다. 고지방식이를 공급한 HF군은 정상 대조군에 비하여 단위 체중당 골격 근육 무게가 유의하게 감소하였으며, 혈당은 유의적으로 증가하였다. 고지방식이와 함께 아연을 보충 공급한 HF+Zn군은 아연을 보충하지 않은 HF군과 비교하여, 공복 혈당과 경구 포도당 부하 후 혈당 증가 면적이 유의하게 감소하였다. 또한, HF+Zn군은 HF군에 비해 골격 근육의 ZIP7 단백질 수준이 유의하게 증가하였으며, AKT 활성과 GLUT4 단백질 수준도 유의하게 증가하는 것으로 나타났다. 이상의 결과를 종합해 볼 때, 아연 보충은 비만으로 인한 고혈당 증세를 완화하는 효과를 나타내며, 이는 골격 근육에서의 ZIP7 아연 수송체에 의한 당 대사 조절과 관련이 있을 것으로 생각된다.

• Journal of Nutrition and Health
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• 제21권4호
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• pp.242-252
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• 1988

Branched-chain 아미노산이인 leucine이 골격근육의 단백질 합성을 촉진하는 요소로 보고되어 왔다. 이러한 역할은 다른 아미노산도 나타낼 수 없는 특이한 것이나 생체로부터 분리된 근육(isolated muscle system)에서 라는 제한된 실험조건하에 얻어진 결과에 바탕하므로, 본 연구는 생체내에서 leucine이 단백질의 생합성에 미치는 영향을 조사하고자 시도되었다. 실험동물은 정상으로 먹이를 먹인 또는 하루 굶게된 주로 leucine군과 비교군으로 나누었다. Leucine군은 80 또는 $160\mu\textrm{moles}$의 leucine을 복강으로 한번 주사하여 주입받았고 비교군에는 생리적 식염수를 같은 방법으로 주입했다. 단백질 합성속도는 $^{14}\textrm{C}-tyrosine을 주사한 후 근육의 단백질에 혼입된 $^{14}\textrm{C}의 량으로 측정하였다. 본 연구에 이용된 근육은 두가지 형태의 뒷다리 근육 즉 oxidative형 soleus와 glycolytic형 extensor digitorium longus(EDL)와 plataris근육이었다. 만 하루 굶게된 뒤의 EDL과 plantaris 근육은 $160\mu\textrm{moles}$의 leucine에 의해 단백질 합성 속도가 24%, 29% 씩 각각 상승했다. 하루 굶게된 쥐의 soleus근육과 정상으로 먹인 쥐의 어느 근육도 첨가된 leucine에 대해 반응을 보이지 않았다. Leucine에 의해 단백질 합성 속도가 상승된 근육은 굶게되므로 합성속도가 정상군의 54%로 떨어졌고 soleus근육은 정상군의 78%에 상당한 단백질 합성 능력을 가지고 있었다. 따라서 생체로부터 분리된 근육에서 동물의 영양상태나 홀몬 분비의 정상여부에 관계없이 leucin이 단백질 생합성 속도를 상승시키는 현상은 생체내에서 재현되지 않았다. 본 연구결과는 식이 제한등으로 인한 스트레스에 민감하게 반응하여 근육내 생성 활동이 저하된 특수한 상태에서만 leucine은 골격근육의 질소 보유능력을 상승시키리라는 것을 시사한다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.994-1001
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• 2007

Changes in shear force value, transverse sections, myofibrils and intramuscular connective tissue of bovine skeletal muscle exposed to the combination of high-pressure up to 400 MPa and heat (30 and $60^{\circ}C$) were studied. The shear force value decreased by pressure-heat treatment up to 200 MPa at 30 and $60^{\circ}C$, and then slightly increased over 200 MPa at $30^{\circ}C$. Shear force values of treated muscles were lower than those of untreated ones. Gaps between muscle fibers in the untreated muscle were a little clear, and then they became very clear in the treated muscles up to 200 MPa at 30 and $60^{\circ}C$. However, the gaps reduced significantly over 200 MPa at $30^{\circ}C$. The remarkable rupture of I-band and loss of M-line materials progressed in the myofibrils with increasing pressure applied. However, degradation and loss of the Z-line in myofibrils observed in the muscle treated at $60^{\circ}C$ was not apparent in the muscle treated at $30^{\circ}C$. The length of the sarcomere initially contracted by pressure-heat treatment of 100 MPa at $30^{\circ}C$ seemed to have recovered with increase of the pressure up to 400 MPa. In the muscle treated at $60^{\circ}C$, the length of sarcomere gradually decreased with increase of the pressure up to 400 MPa. In the treated muscles, changes in the honeycomb-like structure of endomysium were observed and accelerated with increase of the pressure. A wavy appearance clearly observed at the inside surface of endomysium in the untreated muscles gradually decreased in the treated muscles with increase of the pressure. Tearing of the membrane was observed in the muscles treated over 150 MPa at $30^{\circ}C$, as observed in the sample pressurized at 100 MPa at $60^{\circ}C$. The roughening, disruption and fraying of the membrane were observed over 200 MPa at $60^{\circ}C$. From the results obtained, the combination of high-pressure and heat treatments seems to be effective to tenderize tough meat. The shear force value may have some relationship with deformation of intramuscular connective tissue and myofibrils.

• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.479-486
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• 2016

A previous genome-wide association study (GWAS) exposed histone deacetylase 2 (HDAC2) as a possible candidate gene for breast muscle weight in chickens. The present research has examined the possible role of HDAC2 in skeletal muscle development in chickens. Gene expression was measured by quantitative polymerase chain reaction in breast and thigh muscles during both embryonic (four ages) and post-hatch (five ages) development and in cultures of primary myoblasts during both proliferation and differentiation. The expression of HDAC2 increased significantly across embryonic days (ED) in breast (ED 14, 16, 18, and 21) and thigh (ED 14 and 18, and ED 14 and 21) muscles suggesting that it possibly plays a role in myoblast hyperplasia in both breast and thigh muscles. Transcript abundance of HDAC2 identified significantly higher in fast growing muscle than slow growing in chickens at d 90 of age. Expression of HDAC2 during myoblast proliferation in vitro declined between 24 h and 48 h when expression of the marker gene paired box 7 (PAX7) increased and cell numbers increased throughout 72 h of culture. During induced differentiation of myoblasts to myotubes, the abundance of HDAC2 and the marker gene myogenic differentiation 1 (MYOD1), both increased significantly. Taken together, it is suggested that HDAC2 is most likely involved in a suppressive fashion in myoblast proliferation and may play a positive role in myoblast differentiation. The present results confirm the suggestion that HDAC2 is a functional gene for pre-hatch and post-hatch (fast growing muscle) development of chicken skeletal muscle.

• 한국어병학회지
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• 제34권1호
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• pp.63-70
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• 2021

As a part of research to elucidate the pathogenesis of so called Soft Tunic Syndrome(STS), that caused mass mortalities in the cultured sea squirts, Halocynthia roretzi, the epidemiological and pathological analysis were done to both clinically normal and diseased groups of the farms of Tongyoung and Geoje coastal areas in southeast sea from February to July, 2008. In the histological finding of the tunic, most of individuals showed tunic softness syndromes that included the disarrangement and destruction of tunic fiber with the simultaneous presence of flagellates-like cells, recently suspected as main agents of tunic softness syndromes. Simultaneously, the intensive degenerative changes of the skeletal muscle of diseased sea squirts were recognized. The changes were characterized with the hyalinization and condensation of muscle fibril and hemocytic infiltration in the muscle fibers. Those were thought to be a kind of typical Zenker's necrosis as in the skeletal muscle of higher vertebrates. Besides of the diseased sea squirts, Zenker's necrosis of skeletal muscles were seen in the normal ones. Epidemiological inquiry for diseased groups revealed that the higher incidences of tunic softness syndrome were recorded in the fast growing groups and in the sites presuming the organic pollution. And Higher malondialadehyde(MDA) and glutathione peroxidase(GPx) activity were detected in the groups showing STS. Those results suggested that Zenker's necrosis of body muscles was a kind of"nutritional myopathy" by oxidative stress. Conclusively, it was considered that Zenker's necrosis of body muscles gives an important clue for elucidating pathogenesis of STS of cultured squirts. And it seems that the necrosis were caused by the oxidative stress to body muscle during abnormal rapid growth of sea squirts.

• PNF and Movement
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• 제2권1호
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• pp.35-47
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• 2004

Purpose : The purpose of this article was to review the literature on contractile properties of skeletal muscle with reference to its molecular and functional diversity. Method : This review outlines scientific findings regarding different contractile properties in skeletal muscle fibers, and discusses their involvement in functional diversity. Result & Conclusions: Muscle fibers possess distinct mechanical and energetic properties. Myosis, one of the primary contractile muscle proteins, displays structural, functional variability and plays the role of the molecular motor of muscle contraction. Muscle satellite cells are normally mitotically quiescent, but initiate proliferation and give rise to daughter myogenic precursor cells as required for the postnatal growth and regeneration of adult muscle. Passive extensibility is an important component of total muscle function because it allows for the maximal length of skeletal muscles. Proprioceptive neuromuscular facilitation(PNF) stretching can help to restore or improve flexibility and coordination, thereby improving overall muscle function.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.36.2-36
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• 2002

.Developing a skeletal framework artificial hand similar to real human hand. .Developing a micro artificial muscle actuated by pneumatic power. .Building a micro pneumatic system including micro atuators and its control devices. .Building a soft driving system for Service robots. .Designning and Fabricating a multi-channel micro pneumatic valve using MEMS technology.

• The Korean Journal of Physiology
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• 제21권2호
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• pp.323-325
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• 1987

The concentrations of glucose and glycogen in the normal gastrocnemius muscles of Uromastix hardwickii were $88.82{\pm}4.52\;mg/100\;gm$ and $158.98{\pm}23.19\;mg/100gm$ of wet weight of the muscle, respectively. 14-days denervation period has no any effect on glucose contents while the glycogen concentration was decreased to 1/3 of the normal control innervated muscles.

• Journal of Periodontal and Implant Science
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• 제45권1호
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• pp.8-13
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• 2015

Purpose: The aim of this study was to evaluate the transfer of different occlusal forces in various skeletal malocclusions using finite element analysis (FEA). Methods: Three representative human cone-beam computed tomography (CBCT) images of three skeletal malocclusions were obtained from the Department of Orthodontics, Yonsei University Dental Hospital, Seoul, South Korea. The CBCT scans were read into the visualization software after separating bones and muscles by uploading the CBCT images into Mimics (Materialise). Two separate three-dimensional (3D) files were exported to visualize the solid morphology of skeletal outlines without considering the inner structures. Individual dental impressions were taken and stone models were scanned with a 3D scanner. These images were integrated and occlusal motions were simulated. Displacement and Von Mises stress were measured at the nodes of the FEA models. The displacement and stress distribution were analyzed. FEA was performed to obtain the 3D deformation of the mandibles under loads of 100, 150, 200, and 225 kg. Results: The distortion in all three skeletal malocclusions was comparable. Greater forces resulted in observing more distortion in FEA. Conclusions: Further studies are warranted to fully evaluate the impact of skeletal malocclusion on masticatory performance using information on muscle attachment and 3D temporomandibular joint movements.

• The Journal of Korean Physical Therapy
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• 제20권1호
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• pp.57-65
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• 2008

Purpose: Heat shock proteins (HSPs) are a group of proteins that are activated when cells are exposed to a variety of environmental stresses, such as infection, inflammation, exposure to toxins, starvation, hypoxia, brain injury, or water deprivation. The activation of HSPs by environmental stress plays a key role in signal transduction, including cytoprotection, molecular chaperone, anti-apoptotic effect, and anti-aging effects. However, the precise mechanism for the action of small HSPs, such as HSP27 and mitogen-activated protein kinases (MAPKs: extracellular-regulated protein kinase 1/2 (ERK1/2), p38MAPK, stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), is not completely understood, particularly in application of cell stimulators including platelet-derived growth factor (PDGF), angiotensin II (AngII), tumor necrosis factor $\alpha$ (TNF$\alpha$), and $H_2O_2$. This study examined the relationship between stimulators-induced enzymatic activity of HSP27 and MAPKs from rat smooth and skeletal muscles. Methods: 2-dimensional electrophoresis (2DE) and matrix assisted laser desorption ionizationtime-of-flight/time-of-flight (MALDI-TOF/TOF) analysis were used to identify HSP27 from the intact vascular smooth and skeletal muscles. Three isoforms of HSP27 were detected on silver-stained gels of the whole protein extracts from the rat aortic smooth and skeletal muscle strips. Results: The expression of PDGF, AngII, TNF$\alpha$, and $H_2O_2$-induced activation of HSP27, p38MAPK, ERK1/2, and SAPK/JNK was higher in the smooth muscle cells than the control. SB203580 (30${\mu}$M), a p38MAPK inhibitor, increased the level of HSP27 phosphorylation induced by stimulators in smooth muscle cells. Furthermore, the age-related and starvation-induced activation of HSP27 was higher in skeletal muscle cells (L6 myoblast cell lines) and muscle strips than the control. Conclusion: These results suggest, in part, that the activity of HSP27 and MAPKs affect stressors, such as PDGF, AngII, TNF$\alpha$, $H_2O_2$, and starvation in rat smooth and skeletal muscles. However, more systemic research will be needed into physical therapy, including thermotherapy, electrotherapy, radiotherapy and others.