17Beta-estradiol Stimulates Glucose Uptake Through Estrogen Receptor and AMP-activated Protein Kinase Activation in C2C12 Myotubes (Korean J Obes 2016;25:190-6)

곽효범 대한비만학회 2017 The Korean journal of obesity Vol.26 No.1

Simvastatin impairs ADP-stimulated respiration and increases mitochondrial oxidative stress in primary human skeletal myotubes

곽효범 Elsevier 2012 FREE RADICAL BIOLOGY AND MEDICINE Vol.52 No.1

Exercise training attenuates age-induced elevation in Bax/Bcl-2 ratio, apoptosis, and remodeling in the rat heart

곽효범 FEDERATION OF AMERICAN SOC OF EXP BIOLOGY 2006 The FASEB Journal Vol.20 No.6

Core concept of integrative medicine: physical activity

곽효범 한국한의학연구원 2016 Integrative Medicine Research Vol.5 No.3

Exercise and obesity-induced insulin resistance in skeletal muscle

곽효범 한국한의학연구원 2013 Integrative Medicine Research Vol.2 No.4

The skeletal muscle in our body is a major site for bioenergetics and metabolism during exercise. Carbohydrates and fats are the primary nutrients that provide the necessary energy required to maintain cellular activities during exercise. The metabolic responses to exercise in glucose and lipid regulation depend on the intensity and duration of exercise. Because of the increasing prevalence of obesity, recent studies have focused on the cellular and molecular mechanisms of obesity-induced insulin resistance in skeletal muscle. Accumulation of intramyocellular lipid may lead to insulin resistance in skeletal muscle. In addition, lipid intermediates (e.g., fatty acyl-coenzyme A, diacylglycerol, and ceramide) impair insulin signaling in skeletal muscle. Recently, emerging evidence linking obesity-induced insulin resistance to excessive lipid oxidation, mitochondrial overload, and mitochondrial oxidative stress have been provided with mitochondrial function. This review will provide a brief comprehensive summary on exercise and skeletal muscle metabolism, and discuss the potential mechanisms of obesity-induced insulin resistance in skeletal muscle.

노화에 의한 골격근 미토콘드리아 기능부전과 인슐린 저항성에 대한 운동의 역할

곽효범 한국운동재활학회 2015 한국운동재활학회 학술대회 Vol.2015 No.05

골격근 미토콘드리아와 인슐린저항성: 운동의 역할

곽효범 ( Hyo Bum Kwak ) 대한비만학회 2015 The Korean journal of obesity Vol.24 No.2

골격근, 간, β-세포, 지방세포, 위장, α-세포, 신장 그리고 뇌에서의 인슐린저항성은 비만 및 제2형 당뇨병 유발의 중요한 요인들이다. 이중에서 체중의 40-50%를 차지하고 있는 골격근의 인슐린저항성은 골격근 안으로의 포도당 흡수를 감소시킨다. 많은 선행연구들에 의하면 제2형 당뇨병 환자나 인슐린저항성이 있는 비만한 환자들은 정상인에 비해 골격근 내 적은 미토콘드리아가 존재한다고 보고되고 있다. 하지만 골격근 내 미토콘드리아가 인슐린저항성을 유발하는 원인인지에 대해서는 많은 논쟁이 되고 있다. 먼저 골격근의 인슐린저항성이 미토콘드리아의 기능장애와 관련되어 있다는 주장은 다음과 같은 가설에 근거하고 있다. 1) 비만 또는 제2형 당뇨병은 골격근의 지방산화 능력을 감소시키고 인슐린저항성을 유발하는 지방형성 중간물질들(예, FA-CoA, DAG, ceramide)의 축적을 증가시킨다. 2) 비만 또는 고지방섭취에 의한 인슐린저항성은 골격근 내 미토콘드리아의 과부하와 불완전한 지방산화에 의해 야기된다. 3) 골격근 내 미토콘드리아에서 생성된 산화적 스트레스(예, H2O2)가 비만 및 고지방섭취에 의한 인슐린저항성을 유발한다. 하지만 골격근 내 미토콘드리아의 기능장 애는 인슐린저항성을 유발하지 않는다는 상반된 주장도 다음과 같은 이유로 제기되고 있다. 1) 고지방섭취 동물은 인슐린저항성 유발뿐만 아니라 골격근 내 미토콘드리아의 증가도 야기한다. 2) 제2형 당뇨병과 인슐린저항성이 있는 비만한 환자들은 정상인에 비해 높은 골격근 지방산화능력을 나타낸다. 그러나 여러 가지 형태의 운동(일회성vs. 장기간, 유산소 vs. 저항성)은 비만과 제2형 당뇨병에 의해 야기되는 인슐린저항성을 처치하고 예방하는데 매우 중요한 역할을 한다. Insulin resistance in skeletal muscle, liver, β-cells, fat cells, the gastrointestinal track, α-cells, kidneys, and brain represents the core defect in obesity or type 2 diabetes (T2D). Among them, skeletal muscle insulin resistance due to obesity or T2D is manifested by decreased glucose uptake because skeletal muscle comprises 40-50% of the total human body mass. Many previous reports indicate that T2D patients or obese insulinresistant individuals have less mitochondria in their skeletal muscles than lean control subjects. Whether or not mitochondria in skeletal muscle play a causal role in insulin resistance has been debated. A large number of studies demonstrated that skeletal muscle insulin resistance is associated with mitochondrial deficiency including 1) reduced fatty acid oxidation and increased accumulation of lipid intermediates (e.g., FA-CoA, DAG, ceramide), 2) increased mitochondrial overload and incomplete fatty acid oxidation, and 3) increased mitochondrial oxidative stress (e.g., H2O2) in skeletal muscle. In contrast, some studies demonstrated that mitochondrial dysfunction in skeletal muscle is not responsible for insulin resistance, suggesting that 1) the development of insulin resistance in high-fat diet animals occurs with increased muscle mitochondria, and 2) fatty acid oxidation is higher in T2D patients and obese insulin-resistant individuals compared with lean control subjects. However, various types of exercises (acute vs chronic, aerobic vs resistance) are critical in the treatment and prevention of insulin resistance in obesity and T2D.

연산 효율적인 SIA 적응필터를 적용한 음향 반향 제거기의 설계 및 구현

곽효범(Hyo-Bum Kwak),고광철(Kwang-Cheol Ko) 한국통신학회 2004 한국통신학회 학술대회 및 강연회 Vol.2004 No.4

비만과 운동이 정자의 질과 기능에 미치는 영향

박세환,곽효범,윤진환 국민체육진흥공단 한국스포츠정책과학원 2019 체육과학연구 Vol.30 No.1

[Purpose] Sperm quality and function are reduced by environmental factors (e.g., obesity), leading to increased infertility worldwide. Therefore, the purpose of this review paper was to investigate the effects of obesity and exercise training on sperm quality and function in animal and human models. [Methods] In order to determine the effects of obesity and exercise on sperm quality, motility, morphology, testosterone, oxidative stress, inflammation, we reviewed previous literatures with MEDLINE, PubMed, and Scopus databases. [Results] The most important factor to control the sperm motility is calcium ion, which is performed by the protein of CatSper (Cation Channel of Sperm). Obese men showed the decrease of number, concentration, motility, and volume in sperm, resulting in delayed or failed fertility. However, regular exercise training increased sperm-mediated factors including number, motility, and morphology, and festicular function-mediated factors including sperm concentration and serum testosterone. [Conclusions] While obesity exacerbates sperm quality and function in men, regular exercise training with moderate intensity increases sperm number and motility and reduces oxidative stress and inflammation, leading to the improvement of men’s fertility. [목적] 전 세계적으로 남성의 정자 질과 기능은 비만 등과 같은 환경적인 요인에 의해 지속적으로 감소하여 불임율이 증가하는 추세에 있다. 따라서 본 연구의 목적은 비만이 정자의 질과 기능에 미치는 영향을 구체적으로 살펴보고, 운동이 정자의 매개변수에 미치는 효과를 분석하는데 있다. [방법] 비만과 운동이 정자의 수, 운동성, 형태학적 변화, 테스토스테론, 산화적 스트레스, 염증 등에 미치는 영향에 대한 선행 연구들을 조사하기 위하여 MEDLINE, PubMed, Scopus 데이터베이스를 활용하였다. [결과] 정자의 운동성을 조절하는 가장 중요한 요인은 칼슘 이온으로, 칼슘 이온의 작용은 CatSper(Cation Channel of Sperm) 단백질과 같은 칼슘 채널을 통해 가능하다. 비만한 남성은 감소된 정자의 수, 농도 및 운동성을 보이고, 정자의 부피도 감소하여 임신이 지연되고 성공률도 낮아진다고 보고되었다. 그러나, 규칙적인 운동은 정자의 매개변수인 정자수, 운동성과 형태학을 유의하게 증가시키고, 고환 기능 매개변수인 정자 농도와 혈중 테스토스테론을 향상시킨다고 보고되고 있다. [결론] 비만은 남성의 정자 질과 기능을 악화시키지만 적정수준의 규칙적인 운동은 정자 수와 운동성을 증가시키고, 산화적 스트레스와 염증을 감소시켜 결국 남성의 생식력을 향상시킨다.

Treadmill Exercise Improves Memory Function Depending on Circadian Rhythm Changes in Mice

황동섭,곽효범,고일규,김성은,진준장,지은상,최현희,권오영 대한배뇨장애요실금학회 2016 International Neurourology Journal Vol.20 No.S1

Purpose: Exercise enhances memory function by increasing neurogenesis in the hippocampus, and circadian rhythms modulate synaptic plasticity in the hippocampus. The circadian rhythm-dependent effects of treadmill exercise on memory function in relation with neurogenesis were investigated using mice. Methods: The step-down avoidance test was used to evaluate short-term memory, the 8-arm maze test was used to test spatial learning ability, and 5-bromo-2’-deoxyuridine immunofluorescence was used to assess neurogenesis. Western blotting was also performed to assess levels of synaptic plasticity-associated proteins, such as brain-derived neurotrophic factor, tyrosine kinase receptor B, phosphorylated cAMP response element-binding protein, early growth response protein 1, postsynaptic density protein 95, and growth-associated protein 43. The mice in the treadmill exercise at zeitgeber 1 group started exercising 1 hour after sunrise, the mice in the treadmill exercise at zeitgeber 6 group started exercising 6 hours after sunrise, and the mice in the treadmill exercise at zeitgeber 13 group started exercising 1 hour after sunset. The mice in the exercise groups were forced to run on a motorized treadmill for 30 minutes once a day for 7 weeks. Results: Treadmill exercise improved short-term memory and spatial learning ability, and increased hippocampal neurogenesis and the expression of synaptic plasticity-associated proteins. These effects of treadmill exercise were stronger in mice that exercised during the day or in the evening than in mice that exercised at dawn. Conclusions: Treadmill exercise improved memory function by increasing neurogenesis and the expression of synaptic plasticity- associated proteins. These results suggest that the memory-enhancing effect of treadmill exercise may depend on circadian rhythm changes.