• 한국어병학회지
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• 제26권1호
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• pp.45-50
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• 2013

Enrofloxacin is one of the normally used flouroquinolones in mammalian and fish but its withdrawal time and studies were remain obscure. The residual contents of enrofloxacin in fish muscle were analyzed by using HPLC-FLD. More than 0.1 mg/kg of ENR was detected in muscle tissues and the residues were found over 1 year after treatment. The concentration of ENR in Paralichthys olivaceus was not affected by water temperature and lasted for an extended amount of time. The spike recoveries of ENR in the muscle tissue ranged from 78% to 85%. From this results, we need the prescription by veterinarian or aquatic organism disease inspector in ENR usage to assure safety of fish. Future research is required to determine the recommendation dose of ENR for side effects and safety.

• 대한본초학회지
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• 제38권5호
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• pp.31-37
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• 2023

Objective : This study was conducted to investigate the muscle-improving and therapeutic effects of Boehmeria platanifolia (BP) in a mouse model of dexamethasone-induced muscle atrophy. Methods : Muscle atrophy was induced in C57BL/6 mice by intraperitoneal administration of dexamethasone for 12 days. BP extract was administered orally at doses of 100 mg/kg and 200 mg/kg for 19 days, starting 7 days before the intraperitoneal administration of dexamethasone. Mice were weighed during the experimental period, and muscle strength and muscle weight were measured at the end of the experiment. The gastrocnemius (GASTROC) muscles of mice were isolated and the cross-sectional area (CSA) of the muscle fibers was measured after H&E staining. Results : Dexamethasone-induced muscle atrophy mice had a decrease in body weight compared to normal mice, and BP-administrated mice did not show significant change in body weight compared with a control group. Muscle strength in mice with induced muscle atrophy was reduced compared to normal and significantly increased with BP administration and positive control. In addition, the weight of the quadriceps (QUAD) muscle and fiber size of the GASTROC muscle, which was reduced in sarcopenia-induced mice, was increased by BP. Conclusion : BP extract increased muscle strength, muscle weight, and muscle fiber size in dexamethasone-induced muscle atrophy mice. This suggests that the efficacy of BP extracts in improving muscle strength and preventing and treating sarcopenia may be beneficial for the development of potential therapeutic or functional products.

• BMB Reports
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• 제39권4호
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• pp.457-463
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• 2006

Insulin resistance is commonly observed in patients prior to the development of type 2 diabetes and may predict the onset of the disease. We tested the hypothesis that impairment in insulin stimulated glucose-disposal in insulin resistant patients would be reflected in the gene expression profile of skeletal muscle. We performed gene expression profiling on skeletal muscle of insulin resistant and insulin sensitive subjects using microarrays. Microarray analysis of 19,000 genes in skeletal muscle did not display a significant difference between insulin resistant and insulin sensitive muscle. This was confirmed with real-time PCR. Our results suggest that insulin resistance is not reflected by changes in the gene expression profile in skeletal muscle.

• 운동영양학회지
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• 제15권4호
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• pp.153-161
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• 2011

The maintenance of skeletal muscle mass is very important for the prevention of life style-related diseases and the improvement of quality of life. It is well-known that resistance exercise and nutrition (especially amino acids) are the most effective interventions for maintaining skeletal muscle mass. It has been reported that many molecules are involved in the regulation of protein synthesis in response to resistance exercise and nutrition. Understanding the molecular mechanisms regulating muscle protein synthesis is crucial for the development of appropriate interventions. The role of intracellular signaling pathways through the mammalian target of rapamycin (mTOR), a serine/threonine protein kinase in the regulation of muscle protein synthesis, has been extensively investigated for these years. Control of protein synthesis by mTOR is mediated through phosphorylation of downstream targets that modulate translation initiation and elongation step. In contrast, upstream mediators regulating mTOR and protein synthesis in response to resistance exercise and amino acid still needed to be determined. In this brief review, we discuss the current progress of intracellular mechanisms for exercise- and amino acid-induced activation of mTOR pathways and protein synthesis in skeletal muscle.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.693-694
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• 2007

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.640-647
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• 2008

Breed differences in adult animals are determined during fetal development. If interventions are to be developed that influence growth of muscle and fat, it is important to know at which time during gestation breed differences appear and are fixed. The objective of this study was to characterize fetal development in cattle of different breeds. Pregnant cows of 4 cattle breeds with different growth impetus and muscularity were slaughtered under normal processing conditions and the fetuses were removed. German Angus, a typical beef cattle; Galloway, a smaller, environmentally resistant beef type; Holstein Friesian, a dairy type; and Belgian Blue, an extreme type for muscle growth were used. Fetuses of each breed were investigated at 3, 6, and 9 mo of gestation. Fetuses were weighed and dissected into carcass, organs, and muscles. Body fat weight was obtained using the Soxhlet extraction method. Fetal weight increased most rapidly in the third trimester of gestation mainly due to the accelerated muscle and fat deposition. The organ weight to body weight (BW) ratios decreased and the muscle and fat weight to BW ratios increased. At 3 mo of gestation, Galloway fetuses had the significantly smallest BW, half-carcass weight, leg weight, organ weight, muscle weight and shortest leg length. In contrast, Holstein fetuses had the significantly greatest BW, liver, kidney, and lung weights and significantly longest leg length among the 4 breeds, but no differences between Holstein Friesian and Belgian Blue were detected in half-carcass and leg weight. Indeed, Belgian Blue fetuses had the significantly greatest half-carcass weight, leg weight, and muscle weight at 9 mo of gestation, and Galloway had a significantly greater body fat to BW ratio than Holstein Friesian and Belgian Blue. These differences were not evident at 3 and 6 mo of gestation. These data show that the profound increase of tissue and organ weights occurred in later gestation in cattle fetuses even though breed differences were evident as early as 3 mo of gestation. Depending on the tissue of interest, impacting fetal growth likely needs to occur early in gestation before the appearance of breed-specific differences.

• 한국정밀공학회지
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• 제30권7호
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• pp.762-768
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• 2013

This study investigated the effect of whole-body vibration on muscle function and muscular reaction in the knee joint. We recruited thirty healthy subjects and divided them into a training group, who experienced whole-body vibration, and a control group, who did not. The training group performed whole-body vibration exercises for 30 min per day, 3 days a week, for 8 weeks. We measured knee joint torque to estimate muscle strength and reaction, using BIODEX System 3. Knee joint peak torque and total work performed increased significantly in the training group, and muscle acceleration time decreased. These results suggest that stimulation by whole-body vibration can improve muscle strength and reaction by improving muscle tone and increasing blood temperature and flow speed in muscular fiber. Our results also indicate that 4 weeks of exercise with whole-body vibration is required to improve the reaction response, and six weeks to improve strength.

• Molecules and Cells
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• 제20권2호
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• pp.263-270
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• 2005

Transactivation of EGF-receptor (EGFR) by G-protein coupled receptors (GPCRs) is emerging as an important pathway in cell proliferation, which plays a crucial role in the development of atherosclerotic lesion. Angiotensin II (Ang II) has been identified to have a major role in the formation of atherosclerotic lesions, although the underlying mechanisms remain largely unclear. We hypothesize that Ang II promotes the proliferation and migration of smooth muscle cells through the release of heparin-binding epidermal growth factor like growth factor (HB-EGF), transactivation of EGFR and activation of Akt and Erk 1/2, with matrix metalloproteases (MMPs) playing a dispensable role. Primary rat aortic smooth muscle cells were used in this study. Smooth muscle cells rendered quiescent by serum deprivation for 12 h were treated with Ang II (100 nM) in the presence of either GM6001 ($20{\mu}M$), a specific inhibitor of MMPs or AG1478 ($10{\mu}M$), an inhibitor of EGFR. The levels of phosphorylation of EGFR, Akt and Erk 1/2 were assessed in the cell lysates. Inhibition of MMPs by GM6001 significantly attenuated Ang II-stimulated phosphorylation of EGFR, suggesting that MMPs may be involved in the transactivation of EGFR by Ang II receptor. Furthermore Ang II-stimulated proliferation and migration of smooth muscle cells were significantly blunted by inhibiting MMPs and EGFR and applying HB-EGF neutralization antibody, indicating that MMPs, HB-EGF and EGFR activation is necessary for Ang-II stimulated migration and proliferation of smooth muscle cells. Our results suggest that inhibition of MMPs may represent one of the strategies to counter the mitogenic and motogenic effects of Ang II on smooth muscle cells and thereby prevent the formation and development of atherosclerotic lesions.

• The Journal of Korean Physical Therapy
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• 제31권2호
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• pp.129-133
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• 2019

Purpose: This study aimed to investigate effect of ankle instability on peripheral muscle activation among female ballet dancers to provide information on the development of prevention programs for ankle injury rehabilitation. Methods: 32 female ballet dancers were randomly divided into two groups: experience ankle sprain group (n=16, age, $20.7{\pm}0.8years$, BMI $18.6{\pm}1.2kg/m2$) and non-experience ankle sprain group (n=16, $age=21.0{\pm}0.8years$, BMI $19.6{\pm}2.0kg/m2$). Activation of the peroneus longus, tibialis anterior muscle, and gastrocnemius during vertical landing, half pointe, and gait between the two groups were measured. Body composition analyzer was used to examine skeletal muscle mass and body fat mass. Results: A total of 32 patients were included. In the experience ankle sprain group (n=16: left sprain 14, right sprain 2), average ankle sprain injury occurred 7.5 months before the study. The average age of the dancers in the experience ankle sprain group and non-experience ankle sprain group was $20.7{\pm}0.8$ and $21.0{\pm}0.8years$, major period was $64.5{\pm}23.8$ and $71.6{\pm}25.8months$, BMI was $18.6{\pm}1.2$ and $19.5{\pm}2.0kg/m2$, respectively. No significant differences were found on body composition between the two groups (p>0.05). The experience ankle sprain group showed significantly lower tibialis anterior and peroneus longus muscle activation (p<0.5), while gastrocnemius muscle activation appeared to be significantly higher (p<0.05) during landing, half pointe, and normal gait. Conclusion: Ankle sprain can cause a decline in peripheral muscle activation and coordination, which increased the risk for repetitive ankle sprain in the future. Moreover, ankle peripheral muscle selective strength training, coordination program development, and application need to be considered to prevent ankle sprain.

• 한국축산식품학회지
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• 제43권3호
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• pp.512-530
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• 2023

The present study evaluated the effects of fermented whey protein using kimchi lactic acid bacteria Lactobacillus casei DK211 on skeletal muscle mass, muscle strength, and physical performance in healthy middle-aged males performing regular resistance exercises. Effective protein supplementation and regular exercise are two important factors for improving muscle health. Therefore, in this study, the effects of consuming fermented whey protein twice a day were investigated and compared with that of non-fermented supplementation. Forty-eight males (average age 44.8) were randomly assigned to two groups: Fermented whey protein supplementation (FWPS) and non-fermented whey protein concentration supplementation (WPCS) groups. Each group ingested 37 g of FWPS or WPCS twice a day for eight weeks. Body composition, muscle strength, and physical performance were assessed pre- and post-intervention. Independent t-tests or chi-square tests for the categorical variables were performed for analyzing the observations. FWPS was effective in promoting the physical performance in dynamic balance measurement and muscle health, indicated through the increment in grip strength (left), upper arm circumference, and flat leg circumference from the baseline. However, similar improvements were not observed in the WPCS group. These results imply that whey protein fermented by L. casei DK211 is an effective protein supplement for enhancing muscle health in males performing regular resistance exercises.