• 운동영양학회지
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• 제23권2호
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• pp.1-6
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• 2019

[Purpose] Strenuous exercise often induces skeletal muscle damage, which results in impaired performance. Sphingolipid metabolism contributes to various cellular processes, including apoptosis, stress response, and inflammation. However, the relationship between exercise-induced muscle damage and ceramide (a key component of sphingolipid metabolism), is rarely studied. The present study aimed to explore the regulatory role of sphingolipid metabolism in exercise-induced muscle damage. [Methods] Mice were subjected to strenuous exercise by treadmill running with gradual increase in intensity. The blood and gastrocnemius muscles (white and red portion) were collected immediately after and 24 h post exercise. For 3 days, imipramine was intraperitoneally injected 1 h prior to treadmill running. [Results] Interleukin 6 (IL-6) and serum creatine kinase (CK) levels were enhanced immediately after and 24 h post exercise (relative to those of resting), respectively. Acidic sphingomyelinase (A-SMase) protein expression in gastrocnemius muscles was significantly augmented by exercise, unlike, serine palmitoyltransferase-1 (SPT-1) and neutral sphingomyelinase (N-SMase) expressions. Furthermore, imipramine (a selective A-SMase inhibitor) treatment reduced the exercise-induced CK and IL-6 elevations, along with a decrease in cleaved caspase-3 (Cas-3) of gastrocnemius muscles. [Conclusion] We found the crucial role of A-SMase in exercise-induced muscle damage.

• Diabetes and Metabolism Journal
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• 제42권6호
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• pp.488-495
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• 2018

Background: Skeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association. Methods: This prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years. Results: Thigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels. Conclusion: Thigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

• Animal Bioscience
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• 제34권8호
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• pp.1309-1320
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• 2021

Objective: Investigation of muscle growth at different developmental stages is an appropriate strategy for studying the mechanisms underlying muscle development and differences in phenotypes. In particular, the muscle development mechanisms and the difference between the fastest and slowest growth rates. Methods: In this study, we used a growth curve model to fit the growth inflection point (IP) of QingYu pigs and compared differences in the long non-coding RNA (lncRNA) transcriptome of muscle both at the growth IP and plateau phase (PP). Results: The growth curve of the QingYu pig had a good fit (R² = 0.974) relative to a typical S-curve and reached the IP at day 177.96. At the PP, marbling, intramuscular fat, and monounsaturated fatty acids had increased significantly and the percentage of lean muscle and polyunsaturated fatty acids had decreased. A total of 1,199 mRNAs and 62 lncRNAs were differentially expressed at the IP compared with the PP. Additional to gene ontology and Kyoto encyclopedia of genes and genomes pathway analyses, these differentially expressed protein coding genes were principally related to muscle growth and lipid metabolism. Conclusion: Our results suggest that the identified differentially expressed lncRNAs, could play roles in muscle growth, fat deposition and regulation of fatty acid composition at the IP and PP.

• 대한의생명과학회지
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• 제16권3호
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• pp.151-159
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• 2010

The peroxisome proliferator-activated receptor $\alpha$ (PPAR$\alpha$) is a nuclear transcription factor that plays a central role in lipid metabolism and obesity. Exercise also is a powerful modifier of the manifestations of the lipid metabolism and obesity in animal models and humans with obesity and metabolic syndrome. However, effects of exercise on lipid metabolism and obesity in normal-weight younger female subjects, having functional ovaries and not metabolic disease, remain unexplained. To explore the effects of exercise on the development of obesity and its molecular mechanism in high fat diet-fed female C57BL/6J mice, we experimented the effects of swim training on body weight, adipose tissue mass, serum lipid levels, morphological changes of adipocytes and the expression of PPAR$\alpha$ target genes involved in fat oxidation in skeletal muscle tissue of female C57BL/6J mice. Swim-trained mice had significantly decreased body weight, adipose tissue mass, serum triglycerides compared with female control mice. Histological studies showed that swim training significantly decreased the average size of adipoctyes in parametrial adipose tissue. Swim training did not affect the expression of PPAR$\alpha$ mRNA in skeletal muscle. Concomitantly, swim training did not increase mRNA levels of PPAR$\alpha$ target genes responsible for fatty acid $\beta$-oxidation, such as carnitine palmitoyltransferase 1, medium chain acyl-CoA dehydrogenase, enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase, and thiolase in skeletal muscle. In conclusion, these results indicate that swim training regulates lipid metabolism and obesity in high fat diet fed-female mice although swim training did not increase mRNA levels of PPAR$\alpha$ target genes involved in fatty acid $\beta$-oxidation in skeletal muscle, suggesting that swim training may prevent obesity and improve fitness through other mechanisms in female with ovaries, not through the activation of skeletal muscle PPAR$\alpha$.

• Journal of Ginseng Research
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• 제46권3호
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• pp.454-463
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• 2022

Background: Gintonin-enriched fraction (GEF), a non-saponin fraction of ginseng, is a novel glycolipoprotein rich in hydrophobic amino acids. GEF has recently been shown to regulate lipid metabolism and browning in adipocytes; however, the mechanisms underlying its effects on energy metabolism and whether it affects sarcopenic obesity are unclear. We aimed to evaluate the effects of GEF on skeletal muscle atrophy in high-fat diet (HFD)-induced obese mice. Methods: To examine the effect of GEF on sarcopenic obesity, 4-week-old male ICR mice were used. The mice were divided into four groups: chow diet (CD), HFD, HFD supplemented with 50 mg/kg/day GEF, or 150 mg/kg/day GEF for 6 weeks. We analyzed body mass gain and grip strength, histological staining, western blot analysis, and immunofluorescence to quantify changes in sarcopenic obesity-related factors. Results: GEF inhibited body mass gain while HFD-fed mice gained 22.7 ± 2.0 g, whereas GEF-treated mice gained 14.3 ± 1.2 g for GEF50 and 11.8 ± 1.6 g for GEF150 by downregulating adipogenesis and inducing lipolysis and browning in white adipose tissue (WAT). GEF also enhanced mitochondrial biogenesis threefold in skeletal muscle. Furthermore, GEF-treated skeletal muscle exhibited decreased expression of muscle-specific atrophic genes, and promoted myogenic differentiation and increased muscle mass and strength in a dose-dependent manner (p < 0.05). Conclusion: These findings indicate that GEF may have potential uses in preventing sarcopenic obesity by promoting energy expenditure and attenuating skeletal muscle atrophy.

• Nutrition Research and Practice
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• 제17권4호
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• pp.660-669
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• 2023

BACKGROUND/OBJECTIVES: To investigate the effect and regulatory mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise-induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage every day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca²⁺-Mg²⁺-ATPase, Na⁺-K⁺-ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α (PGC-1α)-nuclear respiratory factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism-related enzymes, improve the antioxidant capacity of the body, and promote recovery from exercise-induced fatigue.

• 대한물리의학회지
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• 제13권1호
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• pp.11-26
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• 2018

PURPOSE: The aim of this study was to review the effects of exercise intervention on blood glucose control in obese type 2 diabetic patients. METHODS: The PubMed and KERISS search engines were used and 61 papers that met the key questions were selected. RESULTS: Exercise is an effective intervention for the control of blood glucose in type 2 diabetic patients because it does not impair glucose transport in the skeletal muscle induced by muscle contractions. Insulin resistance, which is characteristic of type 2 diabetes, is caused by decreased insulin sensitivity or insulin responsiveness. Acute exercise improves the glucose metabolism by increasing the insulin-independent signaling pathways and insulin sensitivity in the skeletal muscle, and regular long-term exercise improves the skeletal muscle insulin responsiveness and systemic glucose metabolism by increasing the mitochondrial and GLUT4 protein expression in the skeletal muscle. CONCLUSION: The improvement of the glucose metabolism through exercise shows a dose-response pattern, and if exercise consumes the same number of calories, high intensity exercise will be more effective for the glucose metabolism. On the other hand, it is practically difficult for a patient with obese type 2 diabetes to control their blood glucose with high intensity or long-term exercise. Therefore, it will be necessary to study safe adjuvants (cinnamic acid, lithium) that can produce similar effects to high-intensity and high-volume exercises in low-intensity and low-volume exercises.

• Fisheries and Aquatic Sciences
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• 제23권9호
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• pp.24.1-24.9
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• 2020

Brown alga (Ishige okamurae; IO) dietary supplements have been reported to possess anti-diabetic properties. However, the effects of IO supplements have not been evaluated on glucose metabolism in the pancreas and skeletal muscle. C57BL/6 N male mice (age, 7 weeks) were arranged in five groups: a chow diet with 0.9% saline (NFD/saline group), high-fat diet (HFD) with 0.9% saline (HFD/saline group). high-fat diet with 25 mg/kg IO extract (HFD/25/IOE). high-fat diet with 50 mg/kg IO extract (HFD/50/IOE), and high-fat diet with 75 mg/kg IO extract (HFD/75/IOE). After 4 weeks, the plasma, pancreas, and skeletal muscle samples were collected for biochemical analyses. IOE significantly ameliorated glucose tolerance impairment and fasting and 2 h blood glucose level in HFD mice. IOE also stimulated the protein expressions of the glucose transporters (GLUTs) including GLUT2 and GLUT4 and those of their related transcription factors in the pancreases and skeletal muscles of HFD mice, enhanced glucose metabolism, and regulated blood glucose level. Our results suggest Ishige okamurae extract may reduce blood glucose levels by improving glucose metabolism in the pancreas and skeletal muscle in HFD-induced diabetes.

• 한방비만학회지
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• 제15권2호
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• pp.131-136
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• 2015

Objectives: The prevalence of obesity and metabolic syndrome is increasing worldwide. Regulation of cellular energy metabolis has the potential to be manipulated therapeutically to serve as a target for obesity and insulin resistance. Skeletal muscle is regarded as a target for regulation of energy metabolism and insulin resistance. In this study, the authors investigated the regulatory effect of (Cinnamomum cassia Blume, CCB), Aconitum carmichaeli Debx (ACD), and Benth (Pueraria lobata Benth, PLB) on energy and glucose metabolism in C2C12 myotubes. Methods: The water extracts of CCB, ACD, and PLB (0.5 mg/ml) were treated in differentiated C2C12 myotubes. The expressions of adenosine monophosphate-activated protein kinase (AMPK) and phosphorylation AMPK were detected with western blotting. Glucose metabolism was investigated with glucose uptake assay and glucose consumption assay, total adenosine triphosphate (ATP) content was also analyzed. Results: CCB, ACD, and PLB activated the phophorylation of AMPK, they also increased the glucose metabolism and total ATP contents in C2C12 myotubes. Conclusions: This study suggests that CCB, ACD, and PLB have the potential to increase energy and glucose metabolism in skeletal muscle.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1639-1644
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• 2010

An experiment was conducted to evaluate the effects of dietary acetyl-L-carnitine (ALC) on growth performance, carcass characteristics, meat quality and lipid metabolism in broilers. A total of 240 one-day-old male Arbor Acres broilers were randomly allocated to 4 dietary treatments (0, 300, 600, and 900 mg/kg dietary ALC supplementation, respectively). Compared with the control treatment, addition of ALC resulted in lower (linear effect, p<0.05) ADG and AFI. Abdominal fat percentage decreased (linear effect, p<0.05) as dietary ALC was increased, but there was no effect on dressing percentage, breast muscle percentage or thigh muscle percentage. Breast muscle pH value 24 h post-mortem increased (linear effect, p<0.05), but there were no significant differences among treatments. However, thigh muscle pH value increased (linear effect, p<0.05) as dietary ALC was increased. Breast and thigh muscle $a^*$ values increased (linear effect, p<0.05), and breast and thigh muscle $b^*$ values decreased (linear effect, p<0.05) with increased ALC in the diet. In addition, breast and thigh muscle shear force value decreased (linear effect, p<0.05) as dietary ALC was increased. Total cholesterol, triglyceride, low-density lipoprotein cholesterol and lipoprotein lipase decreased (linear effect, p<0.05) and free fatty acid and lipase in serum increased (linear effect, p<0.05) with increased ALC in diets.