• 운동영양학회지
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• 제23권4호
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• pp.32-35
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• 2019

[Purpose] Fibronectin type III domain containing 5 (FNDC5)/irisin is an exercise-induced myokine, which contributes to cognitive functions. However, the relationship between the neuroprotective effects of FNDC5/irisin and hippocampal dendritic remodeling and astrocyte-secreted factors remains unclear. Therefore, we explored whether subchronic recombinant irisin treatment affected hippocampal morphology and some astrocyte-derived molecules. [Methods] Mice were intraperitoneally injected with irisin (0.5 μg/kg/day) for seven days, followed by their sacrifice two days later. Hippocampal morphometric parameters were analyzed and pgc-1a, fndc5, bdnf, and some astrocyte-derived factors mRNA levels were measured. [Results] Dendritic length, arborization, and spine density were enhanced by irisin regimen in hippocampal CA1 and CA3 areas. Hippocampal pgc-1a, fndc5, and bdnf mRNA levels were significantly increased by irisin treatment. Moreover, hevin mRNA levels were significantly enhanced, whereas tgf-b1 levels downregulated by irisin treatment. [Conclusion] FNDC5/irisin has dendritogenic activity probably through hevin induction and TGF-β1 suppression.

• 대한약침학회지
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• 제20권4호
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• pp.235-242
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• 2017

Irisin is a novel hormone like polypeptide that is cleaved and secreted by an unknown protease from fibronectin type III domain-containing protein 5 (FNDC5), a membrane-spanning protein and which is highly expressed in skeletal muscle, heart, adipose tissue, and liver. Since its discovery in 2012, it has been the subject of many researches due to its potent physiological role. It is believed that understanding irisin's function may be the key to comprehend many diseases and their development. Irisin is a myokine that leads to increased energy expenditure by stimulating the 'browning' of white adipose tissue. In the first description of this hormone, increased levels of circulating irisin, which is cleaved from its precursor fibronectin type III domain-containing protein 5, were associated with improved glucose homeostasis by reducing insulin resistance. Irisin is a powerful messenger, sending the signal to determine the function of specific cells, like skeletal muscle, liver, pancreas, heart, fat and the brain. The action of irisin on different targeted tissues or organs in human being has revealed its physiological functions for promoting health or executing the regulation of variety of metabolic diseases. Numerous studies focus on the association of irisin with metabolic diseases which has gained great interest as a potential new target to combat type 2 diabetes mellitus and insulin resistance. Irisin is found to improve insulin resistance and type 2 diabetes by increasing sensitization of the insulin receptor in skeletal muscle and heart by improving hepatic glucose and lipid metabolism, promoting pancreatic ${\beta}$ cell functions, and transforming white adipose tissue to brown adipose tissue. This review is a thoughtful attempt to summarize the current knowledge of irisin and its effective role in mediating metabolic dysfunctions in insulin resistance and type 2 diabetes mellitus.

• 한국컴퓨터정보학회논문지
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• 제24권9호
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• pp.97-102
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• 2019

Several studies have recently demonstrated that skeletal muscle is an endocrine organ releasing and expressing myokines acting in an endocrine or paracrine manner. Irisin is a hormene-like myokine induced after physical exercise by muscle fibers. It was primarily recognized as a molecule able to advance the "browning response" in white adipose tissue, however, it has been recetly identified that irisin also has a fundamental role in the control of bone mass. We study evidence for its possible skeletal effects, including the fundamental role that irisin is involved in the control of bone mass, with beneficial effects on geometry and cortical mineral density. As loss of muscle mass and bone density occurs with immobility, metabolic disease and aging, future studies researching the efficacy of irisin in reversing muscle wasting and restoring bone would be important to proving irisin as a molecule that combines helpful effects for treating muscular atrophy and osteoporosis in elderly people.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.501-509
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• 2022

Irisin is a myokine caused by exercise that improves insulin resistance and weight loss. However, under unfavorable conditions such as air pollution, and during the pandemic, outdoor activities are uncomfortable. Therefore, in this study, the effect of heat therapy (half bath 42 ± 0.5℃ for 30 min) on irisin circulation levels as an exercise alternative for middle-aged obese women after menopause was investigated. Subjects were 33 women aged 49.54 ± 6.04 years, with parameters of height, 160.12 ± 4.33 cm, weight, 69.71 ± 7.52 kg, body surface area 1.73 ± 0.13 m², body mass index, 27.19 ± 3.40 kg/m². The results suggest that circulating irisin levels showed a significant increase after one-time thermotherapy (TH-1). However, the increase in circulating irisin levels after 15 treatments (TH-15, 5 days/week, 3 weeks) was significantly varied. The level of adiponectin, which increases fatty oxidation to reduce fatty deposition, increased significantly at TH-1, but further increased at TH-15, which was significantly different from the level of TH-1. In addition, the basic serum free fatty acid (FFA) level was significantly increased at TH-15 compared to TH-1. Significant differences were also found in the lipid profile (body mass index, waist circumference, and % body fat). Thermotherapy can significantly increase the tympanic temperature and induce changes in circulating irisin and adiponectin levels. Thus, it resulted in positive changes in FFA and lipid profiles. Therefore, repeated thermotherapy is effective in increasing circulating irisin levels in postmenopausal obese women.

• 한국응용과학기술학회지
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• 제36권4호
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• pp.1268-1280
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• 2019

본 연구는 만 65세 이상 85세 이하의 제2형 당뇨병 비만 여성 노인을 대상으로 12주간 복합운동 후 irisin, 신체조성 및 당 대사에 미치는 영향을 구명하기 위하여 복합운동군(n=20), 대조군(n=16)으로 구분하여 실시하였다. 복합운동 프로그램은 야외 걷기 운동과 탄성 밴드 운동을 12주간 주 3회, 1회 60분간 실시하였으며, 야외 걷기 운동의 운동강도는 중강도(RPE 5~6)로 수행되었으며, 탄성 밴드 운동은 1~4주는 저강도(OMNI-RES 3~4), 5~8주는 중강도(OMNI-RES 5~6), 9~12주는 고강도(OMNI-RES 7~8)로 점진적으로 운동강도를 증가시켰다. 그 결과 복합운동군의 irisin이 유의하게 증가하였고(p<.001), 체지방률은 유의하게 감소하였으며(p<.001), 골격근량은 유의하게 증가하였다(p<.001). 당 대사 관련 인자 중 HbA1c(p=.020), 혈당(p<.001)은 유의하게 감소하였고, HOMA-β는 유의하게 증가하였다(p<.001). Irisin의 변화는 체지방률의 변화와 부적 상관이 있는 것으로 나타났고(r=-.423, p=.010), 유산소성 지구력 변화와 정적 상관이 있었다(r=.355, p=.034). 또한, HbA1c(r=-.351, p=.036)와 혈당(r=-.424, p=.010)의 변화는 부적 상관이 있었으며, HOMA-β는 정적 상관이 있는 것으로 나타났다(r=.411, p=.013). 결론적으로 규칙적인 복합운동의 실천은 제2형 당뇨병 비만 여성노인의 혈중 irisin의 수준을 증가하고, 신체조성 변화에 긍정적인 영향을 주는 것으로 나타났다. 그리고 당화혈색소, 공복혈당 및 인슐린 분비능을 개선하여 당 대사 조절 능력에 도움을 주어 당뇨 예방 및 관리를 위해 효과적인 운동으로 권장될 것으로 사료된다.

• Annals of Occupational and Environmental Medicine
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• 제34권
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• pp.28.1-28.12
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• 2022

Background: Haenyeo is a woman who has the job of collecting seafood in the Jeju Sea at an average temperature of 13℃-14℃. The purpose of this study was to examine the cold acclimatization and occupational characteristics of Haenyeo through biomarkers such as orexin and irisin related to heat generation in the body. Methods: Twenty-one Haenyeo and 25 people with similar age, body type, and body mass index were selected as the control group (Control G). In the cold exposure experiment, a climate chamber was set to 5℃ and both feet were immersed in a 15℃ water tank for 30 minutes. Tympanic temperature (T_ty) and skin temperature (T_sk) were measured, and the mean body temperature (mT_b) was calculated. Blood samples were collected before and immediately after the examination. Orexin and irisin levels were analyzed. Results: Orexin levels were elevated after cold stimulation from 12.17 ± 4.44 to 12.95 ± 4.53 ng/mL (Haenyeo group [Haenyeo G], p < 0.01) and 10.37 ± 3.84 to 11.25 ± 4.02 ng/mL (Control G, p < 0.001). Irisin levels were elevated after cold stimulation from 4.83 ± 2.28 to 5.36 ± 2.23 ng/mL (Haenyeo G, p < 0.001) and 3.73 ± 1.59 to 4.18 ± 2.04 ng/mL (Control G, p < 0.001). The difference between Haenyeo G and Control G values in orexin and irisin appears not only in pre-exposure but also in post-exposure (p < 0.05). Conclusions: Our experimental results suggest that Haenyeo G were relatively superior in cold tolerance to Control G under cold exposure conditions. Haenyeo's cold acclimatization is due to the basic differences in pyrogens regarding body temperature control such as orexin and irisin. This means that Haenyeo are advantageous for cold survival.

• 생명과학회지
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• 제29권6호
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• pp.740-746
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• 2019

운동은 치매에 긍정적인 영향을 줄 수 있다고 잘 알려져 있다. 그러나 대부분의 치매 관련 연구에서는 치매의 증상 완화, 치매에 관한 다양한 치료 및 약물 치료에 대한 연구가 대부분이었다. 규칙적인 운동은 뇌 기능과 치매예방에 중요한 역할을 하지만, 치매와 뇌 기능에 대한 운동의 효과를 나타내는 연구는 부족한 실정이다. 본 연구에서는 운동이 수면 관련 인자(melatonin, serotonin), 치매 관련 인자(BDNF, beta-amyloid, IGF-1, Irisin, GLUT)에 미치는 영향에 대해 연구하고자 한다. 본 연구는 Myokine (Irisin, IGF-1), GLUT 및 Melatonin이 지구성 운동을 통한 BDNF 활성화를 통해 치매 증상을 개선하거나 지연시키는 중요한 인자라는 것을 밝혀냈다. 그러나 이러한 결과는 다양한 종류의 운동 유형, 형태, 기간 및 운동 강도 등에 따라 다른 결과가 나타나서 논란의 여지가 있다. 그러므로 추후 운동과 치매에 관한 기전적인 연구분석이 필요하다.

• 한국체육학회지인문사회과학편
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• 제58권1호
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• pp.271-284
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• 2019

이 연구의 목적은 12주간의 댄스스포츠가 비만노인여성의 신체조성, 아이리신, 아디포넥틴 및 혈중지질에 어떠한 영향을 미치는지 알아보고 비만노인여성을 위한 효과적인 운동프로그램을 제안하는데 있다. 의학적 질환과 증상이 없는 65세 이상 비만노인여성 26명을 대상으로 운동군 13명과 대조군에 13명을 무작위 배정하여 실시하였으며. 운동군은 12주간, 주 2회, 일일 60분 댄스스포츠를 실시하였고 대조군은 동일 처치 기간 동안 일상생활을 유지하도록 했다. 이 연구의 결과에서 혈중 아이리신 농도는 운동군에서 유의하게 증가하였으며, 아디포넥틴 농도는 운동군에서 증가하는 경향을 보였다. 혈중지질의 TG, LDL-C농도는 운동군에서 유의하게 감소하였고, TC과 HDL-C농도는 운동군에 감소 및 증가하는 경향이 나타났다. 이상의 결과를 종합해 보면 낮은 수준의 아이리신과 아디포넥틴, 혈중 콜레스테롤이 댄스 스포츠 운동 후 비만노인여성에 긍정적인 효과가 나타나 노인 비만 관리를 위한 좋은 운동으로 사료된다.

• Nutrition Research and Practice
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• 제8권2호
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• pp.177-182
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• 2014

BACKGROUND/OBJECTIVES: Irisin, a newly identified hormone, is associated with energy homeostasis. We investigated whether aged garlic extract (AGE) and exercise training intervention could improve body weight, insulin sensitivity, skeletal muscle fibronectin domain containing protein 5 (FNDC-5) levels, and plasma irisin in high-fat diet (HFD). MATERIALS/METHODS: Male Sprague Dawley rats were fed a ND (normal diet, n=5) or HFD (n=28) for 6 weeks. After 6 weeks, all rats were divided into 5 groups for the next 4 weeks: ND, (normal diet, n=5), HFD (high-fat diet, n=7), HFDA (high-fat diet + aged garlic extract, n=7), HFDE (high-fat diet + exercise, n=7), and HFDEA (high-fat diet + exercise + aged garlic extract, n=7). Exercise groups performed treadmill exercises for 15-60 min, 5 days/week, and AGE groups received AGE (2.86 g/kg, orally injected) for 4 weeks. RESULTS: Significant decreases in body weight were observed in the ND, HFDE, and HFDEA groups, as compared with the HFD group. Neither intervention affected the masses of the gastrocnemius muscle or liver. There were no significant differences in glucose levels across the groups. The homeostatic model assessments of insulin resistance were significantly higher in the HFD group, as compared with the ND, HFDA, HFDE, and HFDEA groups. However, skeletal muscle FNDC-5 levels and plasma irisin concentrations were unaffected by AGE or exercise in obese rats. AGE supplementation and exercise training did not affect skeletal muscle FNDC-5 or plasma irisin, which are associated with insulin sensitivity in obese rats. CONCLUSION: Our results suggest that the protection against HFD-induced increases in body fat/weight and insulin resistance that are provided by AGE supplementation and exercise training may not be mediated by the regulation of FNDC-5 or irisin.

• The Korean Journal of Physiology and Pharmacology
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• 제18권5호
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• pp.441-446
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• 2014

Ursolic acid (UA), a type of pentacyclic triterpenoid carboxylic acid purified from natural plants, can promote skeletal muscle development. We measured the effect of resistance training (RT) with/without UA on skeletal muscle development and related factors in men. Sixteen healthy male participants (age, $29.37{\pm}5.14$ years; body mass index=$27.13{\pm}2.16kg/m^2$) were randomly assigned to RT (n=7) or RT with UA (RT+UA, n=9) groups. Both groups completed 8 weeks of intervention consisting of 5 sets of 26 exercises, with 10~15 repetitions at 60~80% of 1 repetition maximum and a 60~90-s rest interval between sets, performed 6 times/week. UA or placebo was orally ingested as 1 capsule 3 times/day for 8 weeks. The following factors were measured pre-and post-intervention: body composition, insulin, insulin-like growth factor-1 (IGF-1), irisin, and skeletal muscle strength. Body fat percentage was significantly decreased (p<0.001) in the RT+UA group, despite body weight, body mass index, lean body mass, glucose, and insulin levels remaining unchanged. IGF-1 and irisin were significantly increased compared with baseline levels in the RT+UA group (p<0.05). Maximal right and left extension (p<0.01), right flexion (p<0.05), and left flexion (p<0.001) were significantly increased compared with baseline levels in the RT+UA group. These findings suggest that UA-induced elevation of serum irisin may be useful as an agent for the enhancement of skeletal muscle strength during RT.