• 대한수의학회지
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• 제32권1호
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• pp.99-109
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• 1992

Pathological studies by light and electron microscope were carried out on the twenty piglets naturally affected by encephalomyocarditis virus infection. Gross findings included pale or yellow, small necrotic foci on myocardium, together with pulmonary edema and liver congestion in some cases. On light microscopy, nonsuppurative interstitial endocarcitis, epicarditis and myocarditis, myocardial infarction, and dystrophic calcification or fibtosis were observed in heart. Perivascular cuffings, gliosis and nonsuppurative meningitis were appeared in brain. Focal or diffuse necrosis with mononuclear cell infiltration in lacrimal gland and multifocal necrosis in liver were observed in some cases. Congestion and edema of lung, hyperemia, hemorrhage and deletion of lymphocytes of lymph nodes and spleen were recognized. On electron microscopy, severe swelling and vacuolization of mitochondria and sarcoplasmic reticulum, large intracellular vacuolation and edema, separation and fragmentation of myofibrils were observed. Virus particles were seen in the sarcoplasm of degenerated cardiac muscle cell.

• 한국식품영양과학회지
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• 제27권2호
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• pp.207-213
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• 1998

These experiments were carried out to investigate the effects of electrical stimulation(ES) and delayed chilling (DC) on the quality characteristics of Hanwoo beef. The left half carcass was treated with ES(550V, 90sec)within postmortem 30min. The electrical stimulated half carcass was subjected to chilling at 16$^{\circ}C$ for 24hr, and then stored at 2$\pm$2$^{\circ}C$ for 15days (ESDC). The right half carcass was stored at 2$\pm$2$^{\circ}C$ for 15 days (NES). ESDC showed a rapid pH fall and tended to reach to pH5.54 at postmortem 2 hrs. But, there was no consistent effect of electrical stimulation and delayed chilling on meat color, cooking loss and water holding capacity. Myofibril fragmentation index was higher than that of NES during storage. ESDC showed lower shear force value and strength consistently than NES. SDS-PAGE band patterns of myofibrils showed the rapid breakdown of troponin T and troponin I band in ESDC, compared with NES, and revealed the specific band below myosin light chain-2 pattern in ESDC.

• 한국식품과학회지
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• 제18권3호
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• pp.173-180
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• 1986

근섬유의 생화학적 특성을 규명하기 위하여 red muscle과 white muscle로 부터 myofibril과 actomyosin을 각각 조제하고 그 생물활성 및 SDS-polyacrylamide gel전기 영동상을 비교하였다. 또한 동물의 중류에 따른 특성의 차이를 알아보기 위하여 소의 근육과 닭의 근육을 비교하였다. Myofibril의 SDS-polyacrylamide gel 전기 영동상으로 부터 red muscle은 white muscle보다 30K성분의 함량이 높다는 사실을 알았다. 소의 근육과 닭의 근육은 actomyosin ATPase활성의 이온강도의존성 및 ATPase activity-pH curve에서 차이를 보였다.

• 한국식품과학회지
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• 제16권3호
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• pp.353-357
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• 1984

PSE돈육에서 근원섬유를 추출하고, 무수석시닐산으로 수식하여 석시닐화하고, 그 조제물의 화학적, 기능적 특성을 검토하였다. 석시닐화근원섬유는 석시닐화율에 상관없이 효소적 기능이 완전히 상실하였고, 무처리근원섬유의 등전점이 pH 5.0인데 비하여 석시닐화근원섬유는 pH 3.0정도에서 침전하였다. 염농도에 따른 용해도는 무처리근원섬유가 염농도의존성이 있음에 비하여 석시닐화근원섬유는 염농도에 관계없이 용해도의 변화가 거의 없었다. 석시닐화근원섬유의 기능적 특성중 열응고성은 현저히 감소하였고, 흡수성은 개선되지 않았으며, 유화용량은 다소 향상되었다.

• Entomological Research
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• 제48권5호
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• pp.429-438
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• 2018

Fine structural characteristics of the cardiac muscle and its sarcomere organization in the black widow spider, Latrodectus mactans were examined using transmission electron microscopy. The arrangement of cardiac muscle fibers was quite similar to that of skeletal muscle fibers, but they branched off at the ends and formed multiple connections with adjacent cells. Each cell contained multiple myofibrils and an extensive dyadic sarcotubular system consisting of sarcoplasmic reticulum and T-tubules. Thin and thick myofilaments were highly organized in regular repetitive arrays and formed contractile sarcomeres. Each repeating band unit of the sarcomere had three apparent striations, but the H-zone and M-lines were not prominent. Myofilaments were arranged into distinct sarcomeres defined by adjacent Z-lines with relatively short lengths of $2.0{\mu}m$ to $3.3{\mu}m$. Cross sections of the A-band showed hexagon-like arrangement of thick filaments, but the orbit of thin filaments around each thick filament was different from that seen in other vertebrates. Although each thick filament was surrounded by 12 thin filaments, the filament ratio of thin and thick myofilaments varied from 3:1 to 5:1 because thin filaments were shared by adjacent thick filaments.

• 한국동물생명공학회지
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• 제38권1호
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• pp.10-16
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• 2023

Intermuscular fat is essential for enhancing the flavor and texture of cultured meat. Mesenchymal stem cells derived from intermuscular adipose tissues are a source of intermuscular fat. Therefore, as a step towards developing a platform to derive intermuscular fat from mesenchymal stem cells (MSCs) for insertion between myofibrils in cultured beef, an advanced protocol of intermuscular adipose tissue dissociation effective to the isolation of MSCs from intermuscular adipose tissues was developed in cattle. To accomplish this, physical steps were added to the enzymatic dissociation of intermuscular adipose tissues, and the MSCs were established from primary cells dissociated with physical step-free and step-added enzymatic dissociation protocols. The application of a physical step (intensive shaking up) at 5 minutes intervals during enzymatic dissociation resulted in the greatest number of primary cells derived from intermuscular adipose tissues, showed effective formation of colony forming units-fibroblasts (CFU-Fs) from the retrieved primary cells, and generated MSCs with no increase in doubling time. Thus, this protocol will contribute to the stable supply of good quality adipose-derived mesenchymal stem cells (ADMSCs) as a fat source for the production of marbled cultured beef.

• Biomolecules & Therapeutics
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• 제31권5호
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• pp.573-582
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• 2023

Muscle atrophy is characterized by the loss of muscle function. Many efforts are being made to prevent muscle atrophy, and exercise is an important alternative. Methylglyoxal is a well-known causative agent of metabolic diseases and diabetic complications. This study aimed to evaluate whether methylglyoxal induces muscle atrophy and to evaluate the ameliorative effect of moderate-intensity aerobic exercise in a methylglyoxal-induced muscle atrophy animal model. Each mouse was randomly divided into three groups: control, methylglyoxal-treated, and methylglyoxal-treated within aerobic exercise. In the exercise group, each mouse was trained on a treadmill for 2 weeks. On the last day, all groups were evaluated for several atrophic behaviors and skeletal muscles, including the soleus, plantaris, gastrocnemius, and extensor digitorum longus were analyzed. In the exercise group, muscle mass was restored, causing in attenuation of muscle atrophy. The gastrocnemius and extensor digitorum longus muscles showed improved fiber cross-sectional area and reduced myofibrils. Further, they produced regulated atrophy-related proteins (i.e., muscle atrophy F-box, muscle RING-finger protein-1, and myosin heavy chain), indicating that aerobic exercise stimulated their muscle sensitivity to reverse skeletal muscle atrophy. In conclusion, shortness of the gastrocnemius caused by methylglyoxal may induce the dynamic imbalance of skeletal muscle atrophy, thus methylglyoxal may be a key target for treating skeletal muscle atrophy. To this end, aerobic exercise may be a powerful tool for regulating methylglyoxal-induced skeletal muscle atrophy.

• The Korean Journal of Physiology and Pharmacology
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• 제5권4호
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• pp.333-342
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• 2001

Adriamycin is a commonly used chemotherapeutic agent for cancer, including acute leukemia, lymphoma, and a number of solid human tumors. However, recent studies have recognized severe cardiotoxicity after an acute dose, which are likely the result of generation of free radicals and lipid peroxidation. Therefore, the clinical uses of adriamycin have been limited. Melatonin, the pineal gland hormone known for its ability to modulate circardian rhythm, has recently been studied in its several functions, including cancer growth inhibition, stimulating the immune system, and acting as an antioxidant and radical scavenging effects. In the present study, we evaluated the effect of melatonin administration on adriamycin-induced cardiotoxicity in rat. Heart slices were prepared using a Stadie-Riggs microtome for the measurement of malondialdehyde (MDA) content used as an index of lipid peroxidation and lactate dehydrogenase (LDH) release as an indicator of lethal cell injury. Serious adriamycin-induced lethality was observed in rat by a single intraperitoneal injection in a dose-dependent manner. A single injection of adriamycin (25 mg/kg, i.p.) induced a lethality rate of 86%, with melatonin (10 mg/kg s.c. for 6 days) treatment reducing the adriamycin-induced lethality rate to 20%. The severe body weight loss caused by adriamycin was also significantly attenuated by melatonin treatment. Treatment of melatonin marked reduced adriamycin-induced the levels of MDA formation and LDH release. A cell damage indicated by the loss of myofibrils, swelling of the mitochondria as well as cytoplasmic vacuolization was seen in adriamycin-treated group. Melatonin attenuated the adriamycin-induced structural alterations. These data provide evidence that melatonin prevents adriamycin-induced cardiotoxicity and might serve as a combination with adriamycin to limit free radical-mediated cardiotoxicity.

• Applied Microscopy
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• 제20권2호
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• pp.127-159
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• 1990

This study was investigated to elucidate the effect of chlorambucil on the heart in aging rats. Male rat ranging in age from 3 to 36 months were used. Each age groups(3, 6, 12, 18, 24, 36 months) included control and chlorambucil treated rats. As a part of the study, the ultrastructural changes in the left ventricular myocardial cells were described by using the qualitative and morphometric techniques. The results are summarized as follows. Age associated ultrastructural changes included: an increase in vacuoles, protrusion of plasma membranes, lipid droplets, and lipofuscins in myocardium of control groups. These changes which begin to occur at 12 months and continue through 36 months. At the 36 months some instance of unusual formation of contraction band and separation of intercalated discs were encountered. Morever, these changes and contents with chlorambucil treatment were remarkably increased in comparison with control groups. Age-dependent changes of control group measured with morphometry were not observed in the volume densities of mitochondria and myofibrils. But there was increase in interstitium. On the other hand decrease in sarcoplasmic reticulum and T-tubule system. In chlorambucil treated groups, volume densities of mitochondria and interstitium were increased in comparison with those of the control groups. But sarcoplasmic reticulum and T-tubule system were remarkably decreased.

• Journal of Yeungnam Medical Science
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• 제5권2호
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• pp.111-119
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• 1988

효소와 기계적인 힘을 이용하여 얻어진 심장세포를 심근세포와 내피세포를 분리하여 48시간 배양한 후 양군으로 나눠서 관찰하였다. 실험군은 배양중에 10% DMSO에 1시간 처리하였고 DMSO를 처리하지 않고 계속 배양한 것을 대조군으로 하였다. DMSO효과를 관찰하기 위하여 도립현미경하에서 세포의 형태, 수축능력, 증식 능력등을 관찰하였고, 심근세포에서는 succinate dehydrogenase 반응으로 사립체의 증감을 대조군과 비교하였고, 심장내과세포에서는 thiamine pyrophosphatase의 반응으로 Golgi의 양을 대조군으로 비교하였다. 실험 결과를 요약하연 다음과 같다. 1. DMSO에 의하여 심근세포는 분화된 형태로 모양이 길어졌고 사립체의 증가에 의해 succinate dehydrogenase의 반응이 대조군보마 강하게 나타났다. 2. DMSO에 의해 심근세포는 근세섬유의 파괴와 혼란이 초래되었고 이로 인하여 수축능력이 감소되었다. 3. 심장내과 세포는 DMSO에 의해 세포증식이 감소되고 고유기능이 강조되어 Golgi의 표지효소안 thiamine pyrophosphatase의 반응이 대조군보다 강하였다. 4. 심장내과세포는 DMSO의 세포접착력 소실과 운동성 소실작용에 의해 배양중 많은 세포의 손실이 초래되었다.