• Molecules and Cells
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• 제23권3호
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• pp.272-279
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• 2007

The maintenance of normal blood glucose levels at rest and during exercise is critical. The maintenance of blood glucose homeostasis depends on the coordination and integration of several physiological systems, including the sympathetic nervous system and the endocrine system. During prolonged exercise increased demand for glucose by contracting muscle causes to increase glucose uptake to working skeletal muscle. Increase in glucose uptake by working skeletal muscle during prolonged exercise is due to an increase in the translocation of insulin and contraction sensitive glucose transporter-4 (GLUT4) proteins to the plasma membrane. However, normal blood glucose level can be maintained by the augmentation of glucose production and release through the stimulation of liver glycogen breakdown, and the stimulation of the synthesis of glucose from other substances, and by the mobilization of other fuels that may serve as alternatives. Both feedback and feedforward mechanisms allow glycemia to be controlled during exercise. This review focuses on factors that control blood glucose homeostasis during prolonged exercise.

• Clinical and Experimental Pediatrics
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• 제50권3호
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• pp.223-229
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• 2007

The fetus is completely dependent on mother for glucose and other nutrient transfer across the placenta. At birth, when the maternal supply is discontinued, the neonate must adjust to an independent existence. The changes in the neonate's glucose homeostasis during this transition to the extrauterine environment are influenced by the mother's metabolism and intrinsic fetal and placental problems. Maturation of carbohydrate homeostasis results from a balance between substrate availability and coordination of developing hormonal, enzymatic, and neural systems. These mechanisms may not be fully developed in neonates, so the neonate is vulnerable to carbohydrate disequilibrium resulting in damage to the central nervous system. Hypoglycemia is a relatively common metabolic problem seen during newborn care. However its definition, management and long term sequalae remain controversial. Hyporglycemia occurs frequently as a transient disorder with excellent prognosis. It also may persist and recur and cause permanent neurological complications. Although the key to effective treatment of hypoglycemia is diagnostic specific, the maintenance of euglycemia is critical to the preservation of central nervous system function. This article discusses physiology of perinatal glucose homeostasis, focusing on evaluation and treatment of hypoglycemia.

• Diabetes and Metabolism Journal
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• 제42권6호
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• pp.465-471
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• 2018

My professional journey to understand the glucose homeostasis began in the 1990s, starting from cloning of the promoter region of glucose transporter type 2 (GLUT2) gene that led us to establish research foundation of my group. When I was a graduate student, I simply thought that hyperglycemia, a typical clinical manifestation of type 2 diabetes mellitus (T2DM), could be caused by a defect in the glucose transport system in the body. Thus, if a molecular mechanism controlling glucose transport system could be understood, treatment of T2DM could be possible. In the early 70s, hyperglycemia was thought to develop primarily due to a defect in the muscle and adipose tissue; thus, muscle/adipose tissue type glucose transporter (GLUT4) became a major research interest in the diabetology. However, glucose utilization occurs not only in muscle/adipose tissue but also in liver and brain. Thus, I was interested in the hepatic glucose transport system, where glucose storage and release are the most actively occurring.

• Clinical and Experimental Reproductive Medicine
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• 제40권2호
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• pp.76-82
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• 2013

Objective: To compare the blood glucose levels, insulin concentrations, and insulin resistance during the two phases of the menstrual cycle between healthy women and patients with premenstrual syndrome (PMS). Methods: From January of 2011 to the August of 2012, a descriptive cross-sectional study was performed among students in the School of Medicine of Jahrom University of Medical Sciences. We included 30 students with the most severe symptoms of PMS and 30 age frequency-matched healthy controls. We analyzed the serum concentrations of glucose, insulin, and insulin resistance by using the glucose oxidase method, radioimmunometric assay, and homeostasis model assessment of insulin resistance equation, respectively. Results: No significant differences between the demographic data of the control and PMS groups were observed. The mean concentrations of glucose of the two study groups were significantly different during the follicular and luteal phases (p=0.011 vs. p<0.0001, respectively). The amounts of homeostasis model assessment of insulin resistance of the two study groups were significantly different in the luteal phase (p=0.0005). Conclusion: The level of blood glucose and insulin resistance was lower during the two phases of the menstrual cycle of the PMS group than that of the controls.

• Biomolecules & Therapeutics
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• 제14권3호
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• pp.132-136
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• 2006

Aryl hydrocarbon receptor nuclear translocator (Arnt) belongs to bHLH-PAS protein family. Here, we study the role of Arnt in both cell growth and glucose metabolism. Our results demonstrated that the absence of Arnt does affect ATP homeostasis but not cell growth in monolayer-cultured mouse hepatoma cells. ATP level of Arnt defective BpRc1 hepatoma cells is less than that of wild type hepatoma cells in both normoxia and hypoxia. BpRc1 cells also fail to increase the expression of glycolytic enzymes in response to hypoxia. Our results suggest that Arnt is essential for glucose metabolism and ATP production but not for cell growth.

• 한국식품과학회지
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• 제53권3호
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• pp.313-320
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• 2021

본 연구는 일반 쿠키(NC), 통밀 쿠키(WC) 그리고 매생이 추출물이 첨가된 통밀 쿠키(WCFE)를 제조하고 4주 동안 쿠키로만 이루어진 식이를 마우스에게 제공한 뒤 혈당과 관련된 지표들의 변화를 관찰하였다. 4주 섭취 이후 NC를 섭취한 그룹과 비교하여 WC와 WCFE를 섭취한 그룹에서 단기간의 체중 증가의 감소효과를 보였으며, 매생이 추출물의 첨가는 간과 신장의 스트레스 증가에 영향이 없음을 확인할 수 있었다. 공복 혈당 수준은 WC 그룹과 WCFE 그룹에서 NC 그룹에 비해 유의적으로 감소하였다(p<0.001). 혈청 인슐린 농도는 WCFE 그룹에서 유의적인 차이를 보이며 감소하였고(p<0.05), 이를 바탕으로 인슐린 저항성 관련 지표인 HOMA-IR를 산출 시 WCFE 그룹에서 유의적인 차이를 보이며 감소함으로써(p<0.05) 매생이 추출물이 첨가되었을 때 인슐린 저항성을 개선한 것으로 판단된다. 또한, OGTT의 30분대 혈당치에서 NC 그룹 및 WC 그룹과 비교하여 WCFE 그룹에서 혈당 증가 폭이 감소하는 것을 확인할 수 있었고, WCFE 그룹에서 가장 낮은 AUC 면적 값을 나타냈다. OGTT 및 AUC 결과를 종합해볼 때 일반 쿠키와 통밀 쿠키에 비해 매생이 추출물의 첨가로 인해 내당능에 도움을 줄 수 있을 것으로 판단된다. 그러나 혈당 관련 유전자인 GLUT2와 GLUT4의 경우, 통밀에 의해 발현이 증가하는 경향은 관찰되었으나 매생이 추출물 첨가에 의한 효과는 관찰되지 않았다. 또한 IRS-1의 경우 WC 그룹에 비해 WCFE 그룹의 발현이 증가하였고 PI3K p85α 발현의 경우 WC 그룹에 비해 WCFE 그룹의 발현이 감소하는 경향을 보여, 매생이 추출물의 첨가가 혈당 관련 유전자의 발현에는 영향을 미치지 못하는 것으로 보인다. 따라서, 이러한 결과를 종합했을 때 WCFE 섭취 시, 혈당 관련 유전자 발현에는 영향을 미치지는 못하지만, 내당능 개선 효과를 가지며 인슐린 저항성 개선 효과의 가능성을 보여 혈당 항상성 개선에 기여할 것으로 판단된다.

• Biomolecules & Therapeutics
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• 제12권4호
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• pp.202-208
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• 2004

Diabetes mellitus is a complex metabolic derangement with hyperglycaemia being the most characteristic symptom of diabetes. Hyperglycaemia can be caused by an increase in the rate of glucose production by the liver or by a decrease in the rate of glucose use by peripheral tissues. Impaired glucose transport is one of the major factors contributing to insulin resistance in type 2 diabetic patients. The ability of insulin to mediate tissue glucose uptake is a critical step in maintaining glucose homeostasis and in clearing the post-prandial glucose load. Glucose transport is mediated by specific carriers called glucose transporters (GLUTs). In this article, the functional importance and molecular mechanisms of insulin-induced glucose transport and development of hypoglycaemic agents which increase glucose transport are reviewed.

• 동의생리병리학회지
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• 제28권1호
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• pp.59-62
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• 2014

Glucose uptake plays a pivotal role in maintaining whole body glucose homeostasis in adipocytes and skeletal muscles. In the present study we have shown that Fructus Piperis Longi Extracts (FPLE) can stimulate glucose uptake in OP9 adipocytes. The increasing effects of FPLE on glucose uptake were inhibited by compound C pretreatment, which means that the glucose uptake effects by FPLE were carried out by AMP-activated protein kinase (AMPK) activation. Further studies revealed that FPLE stimulated glucose transport occurs through a mechanism involving extracellular signal-regulated kinase (ERK1/2) activation.

• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.653-659
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• 1998

• Molecules and Cells
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• 제28권3호
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• pp.139-148
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• 2009

Cell death has been traditionally classified in apoptosis and necrosis. Apoptosis, known as programmed cell death, is an active form of cell death mechanism that is tightly regulated by multiple cellular signaling pathways and requires ATP for its appropriate process. Apoptotic death plays essential roles for successful development and maintenance of normal cellular homeostasis in mammalian. In contrast to apoptosis, necrosis is classically considered as a passive cell death process that occurs rather by accident in disastrous conditions, is not required for energy and eventually induces inflammation. Regardless of different characteristics between apoptosis and necrosis, it has been well defined that both are responsible for a wide range of human diseases. Glycogen storage disease type I (GSD-I) is a kind of human genetic disorders and is caused by the deficiency of a microsomal protein, glucose-6-phosphatase-${\alpha}$ ($G6Pase-{\alpha}$) or glucose-6-phosphate transporter (G6PT) responsible for glucose homeostasis, leading to GSD-Ia or GSD-Ib, respectively. This review summarizes cell deaths in GSD-I and mostly focuses on current knowledge of the neutrophil apoptosis in GSD-Ib based upon ER stress and redox signaling.