• The Journal of Korean Physical Therapy
• /
• 제10권2호
• /
• pp.71-76
• /
• 1998

본 연구는 실험용 려 12마리를 정상관, 2주 고정군, 4주 고정군에 각각 4마리씩 배정하고 석고 고정 기간 후 비복근의 절편을 취하여 투과전자현미경으로 형태학적 관찰을 한 결과를 다음과 같이 요약할 수 있다. 골격근을 짧은 위치로 일정 기간 고정하면 근절의 길이와 폭은 물론 삼조체, 글리코겐, 필라멘트 단백질, 미토콘드리아와 근 세포 핵의 모양까지도 심한 변화가 일어나기 때문에 구축과 위축의 개념에 근원 섬유의 조직, 형태학적 의의를 추가하여야 할 것으로 사료된다.

• Applied Microscopy
• /
• 제19권2호
• /
• pp.85-98
• /
• 1989

The ventricular myocardia of 14, 16, 18 and 20-day-old rat fetuses and newborns have been studies by light and electron microscopic morphometrics. The volume density of the myocyte and interstitial compartments as well as volume, surface and numerical density of nuclei were estimated by light microscopic morphometrics. Whereas, the volume density of myofibrils and glycogen granules as well as the volume, surface and numerical density of mitochondria were assessed by electron microscopic morphometrics. The volume density of myocyte compartment of the ventricular myocardia in developing fetuses decreased, but increased in newborn rats. On the other hand, the volume density of the interstitial compartment increased in growing fetuses and decreased in newborns. In all groups the volume, surface and numerical density of nuclei decreased gradually with elongation of myocytes. Conversely, the volume, surface and numerical density of mitochondria and volume density of myofibrils and glycogen granules in ventricular myocytes incresed. The increase in numerical density of mitochondria probably reflects an increase in metabolic activity. Sarcomere length also increased during development.

• 한국축산식품학회지
• /
• 제32권5호
• /
• pp.578-583
• /
• 2012

The purpose of this study was to evaluate the ultrastructural and shear force changes of duck breast and leg meat during aging at $0^{\circ}C$. Pekin ducks (45 d old) purchased from Greemud Co. were used for this experiment, and were stored at $0^{\circ}C$ for 7 d in order to determine the changes of the meat structure using transmission electron microscopy (TEM) and shear force. At day 0, A-band, I-band, M-line and Z-line of sarcomeres were seen clearly, but sarcomeres started to lose structure and become extended in length from day 2. With extended aging periods, myofibrils were destroyed and symptoms of aging became more obvious. In the duck breast meat, some myofibrils were also destroyed at the Z-line, but were mainly destroyed at the M-line. The change in structure of duck leg meat over time was similar to that of breast meat. After five days and seven days of aging, mitochondria size and quantity were determined to be increased between the myofibrils. Shear force was decreased over time. From this study, aging at $0^{\circ}C$ was found to negatively influence the ultrastructure and shear force of duck meat.

• 한국축산식품학회지
• /
• 제23권4호
• /
• pp.315-320
• /
• 2003

A total of 240 crossbred(Landrace ${\times}$ Yorkshire ${\times}$ Duroc) pigs were housed from 70 kg live weight and slaughtered at weights of 95, 105, 115 and 125 kg. The left side loins of carcass were obtained at 24 hr postmortem to measure pork quality. There were significant differences(p<0.01) in eye muscle area of pork loins between the slaughter weights of 95 and 105 kg. However, no differences were observed in pork than 105 kg of slaughter weight. Ultimate pH values were decreased with increasing slaughter weight and cooking loss was also reduced(p<0.01) at the heavier weights. Slaughter weights did not affect the shear force and intramuscular fat. However, dry matter(DM) and crude protein(CP) contents of loin were increased, and cooking loss and sarcomere length were decreased with increasing slaughter weight. The lightness(L$^{*}$) and redness(a$^{*}$) of pork loin were increased with increasing slaughter weight. Results suggested that pork quality may be improved when pig slaughter weight is increased from 95 to 125 kg.

• 대한의생명과학회지
• /
• 제13권4호
• /
• pp.263-272
• /
• 2007

Nebulin is a giant actin binding protein (600-900 kDa) which is specific to skeletal muscle. This protein is known to regulate thin filaments length in sarcomere as a molecular template. The C-terminus of nebulin is located in the Z-disc of muscle sarcomere and is bound to other proteins such like myopalladin, titin, archvillin, and desmin. The N-terminus of nebulin binds to tropomodulin at the pointed ends of the thin filaments. In recent research, nebulin not only found in brain but also expressed in heart, stomach, and liver. So, the roles of nebulin in non-muscle tissue have been studied. However, lack of information or studies on nebulin binding proteins and nebulin function in brain are available so far. Therefore, the current study have investigated a novel binding partner of Nebulin C-terminus by using yeast two-hybrid screening with human brain cDNA library. Nebulin C-terminus, containing simple repeats, serine rich and SH3 domain, interacts with osteonectin C-terminal region. The specific interaction of nebulin and osteonectin were confirmed in vitro by using GST pull-down assay and reconfirmed in vivo by using transfected COS-7 cells with EGFP-tagged nebulin and DsRed-tagged osteonectin. Consequently, this study identified SH3 domain in nebulin C-terminus specifically binds to extracellular Ca-binding (EeC domain in osteonectin. Also, nebulin C-terminus fusion protein colocalized with osteonectin EC domain fusion protein in transfected COS-7 cells. The current study found the interaction between nebulin and osteonectin in human brain for the first time and suggested the nebulin in brain may be associated with osteonectin, as a regulator of cell cycle progression and mitosis.

• 한국식품과학회지
• /
• 제31권4호
• /
• pp.1005-1010
• /
• 1999

감마선 조사가 쇠고기의 연도개선에 미치는 효과를 조사하기 위하여 도축 직후 쇠고기에 감마선을 조사시켜 전단력의 변화 및 근육의 미세구조를 관찰하였다. 감마선이 조사된 쇠고기는 최고 전단력치에 도달하는 시간이 감마선 조사선량이 증가함에 따라 단축되었다. 감마선 조사가 근육의 초미세구조에 작용하여 근절의 단축을 지연시켰고, Z-line의 수축을 유도하였다. 또한 감마선이 조사된 쇠고기에서 근속과 perimysium의 파괴는 감마선 비조사구에 비해 더 빨리 진행되는 것이 관찰되었다. 결론적으로 감마선 조사는 쇠고기의 사후경직에 도달하는 시간을 단축시키고, 연도개선 효과에 유효한 것으로 사료된다.

• 대한의생명과학회지
• /
• 제7권4호
• /
• pp.167-172
• /
• 2001

Nebulin is an approximately 700 kDa filamentous protein in vertebrate skeletal muscle. It binds to the Z line and also binds side-by-side to the entire thin actin filament in a sarcomere. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. The C-terminal part of human nebulin is anchored in the sarcomeric Z-disk and contains an SH3 domain. SH3 domains have been identified in an ever-increasing number of proteins important for a wide range of cellular processes, from signal transduction to cytoskeleton assembly and membrane localization. However, the exact physiological role of SH3 domains remains, in many cases, unclear. To explore the role of nebulin SH3 in the cytoskeletal rearrangement that accompanies myoblast differentiation, we transfected sense and antisense nebulin SH3 domain fused to enhanced green fluorescent protein in myoblast. Cells expressing nebulin SH3 fragment showed decrease of cell-cell adhesion, and cells transfected with antisense nebulin SH3 gene showed a rounded cell morphology and loss of cell-matrix adhesion. No alteration in cell shape and differentiation were observed in control cells expressing enhanced green fluorescent protein. Perturbation of nebulin altered the cell shape and disrupted cell adhesion in myoblast, demonstrating that nebulin can affect cytoskeleton rearrangement.

• 한국축산식품학회지
• /
• 제37권5호
• /
• pp.716-725
• /
• 2017

The objective of this study was to determine the relationship between composition of muscle fiber types and meat quality traits of eight major muscles from Hanwoo steers. Longissimus lumborum (LL), psoas major (PM), semimembranosus (SM), semitendinosus (ST), gluteus medius (GM), triceps brachii (TB), rectus abdominis (RA) and superficialis flexor (SF) muscles were obtained from 9 Hanwoo steers and subjected to histochemical analysis. There were significant (p<0.05) differences in fiber number percentage (FNP) and fiber area percentage (FAP) of fiber types among these 8 major muscles. SF had the highest FNP of type I (55.9%), followed by PM (46.4%), TB (45.4%), RA (38.5%), LD (36.8%), GM (36.0%), SM (22.2%), and ST (18.8%). FAP of type IIB ranged from 9.9% in SF to 58.7% in ST. Meat quality traits, including fat content, myoglobin content, collagen content, CIE $L^*$ and $a^*$, drip and cooking loss, sarcomere length and Warner-Bratzler shear force, were all significantly (p<0.05) different among these muscles. Due to such diversities among these 8 muscles, lack of correlations were found between fiber type composition and meat quality traits. These results suggest that correlation for each individual muscle should be used to improve meat quality and profitability of retail beef cuts.

• 한국축산식품학회지
• /
• 제30권1호
• /
• pp.42-48
• /
• 2010

This research was conducted to evaluate the effects of cooking conditions on quality characteristics of Soo-Yuk, a traditional Korean food. The cooking conditions were as follows: boiled until the core temperature of a sample in $20^{\circ}C$ cold water reached at $75^{\circ}C$ (T1); boiled until the core temperature of a sample in $90^{\circ}C$ boiling water reached at $75^{\circ}C$ (T2); and boiled with sample from $20^{\circ}C$ to $100^{\circ}C$ and kept at $98^{\circ}C$ for 25 min (T3, Korean traditional method). The sample cooked at $90^{\circ}C$ water (T2) had the fast cooking time, and the highest cooking yield and moisture content. Soo-yuk boiled in $100^{\circ}C$ water (T3) showed the longest cooking time, the lowest cooking yield and moisture content, and the highest shear force. The instrumental color showed a significant difference among the cooking conditions. The sarcomere length of soo-yuk boiled in $100^{\circ}C$ water (T3) was the shortest, but the myofibrillar fragmentation index and thiamine content of the sample cooked at $90^{\circ}C$ (T2) were the highest. In sensory evaluation, the evaluation of soo-yuk boiled in $98^{\circ}C$ water (T3) was of superior flavor and overall acceptability.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권7호
• /
• pp.976-986
• /
• 2015

The present study was conducted to determine the effects of lipid sources with different fatty acids profile on meat fatty acids profile and beef quality traits of Nellore. A total of 45 Nellore animals with an average initial body weight of $419{\pm}11kg$ (at $15{\pm}2mo$) were distributed in a completely randomized design consisting of 5 treatments and 9 replicates. The roughage feed was maize silage (600 g/kg on a dry matter [DM] basis) plus concentrate (400 g/kg on a DM basis). The dietary treatments were as follows: without fat (WF), palm oil (PO), linseed oil (LO), protected fat (PF), and soybean grains (SG). No effects of lipid sources were observed (p>0.05) on beef color, pH, water-holding capacity, and sarcomere length. Beef from cattle fed PO had greater shear-force values (p<0.05) compared to beef from cattle fed WF. Deposition of main unsaturated fatty acids (oleic, linoleic, and linolenic) was greater in treatments WF, SG, and LO, respectively, while the values of conjugated linoleic acid (CLA) were greater when animals were fed LO. The inclusion of LO in the diet enhances the concentration of CLA in longissimus muscle and subcutaneous fat besides improving the atherogenicity index and elongase activity. As such, LO can be used with the aim to improve the quality of beef from confined Nellore cattle. Conversely, the use of PO is not recommended since it may increase the concentration of undesirable unsaturated fatty acids in muscle and subcutaneous fat, shear-force and the atherogenicity index.