• 대한핵의학회:학술대회논문집
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• 1971.11a
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• pp.79.2-79.2
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• 1971

• BMB Reports
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• v.34 no.4
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• pp.285-292
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• 2001

Insulin stimulates glucose uptake in muscle and adipose tissue and thus maintains normal blood glucose level in our body. Derangement of this process causes many grave health problems. Insulin stimulates glucose transport primarily by recruiting GLUT4 from its intracellular storage sites to the plasma membrane. The process is complex and involves GLUT4 trafficking through multiple subcellular compartments (organelles) and many protein functions, details of which are poorly understood. This review summarizes a recent development to isolate and characterize the individual intracellular GLUT4 compartments and to illustrate how this compartmental analysis will help to identify the insulin-sensitive step or steps in the insulin-induced GLUT4 recruitment in rat adipocytes. The review does not cover the recent exciting development in identification of many proteins implicated in this process.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.329-334
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• 1999

Insulin stimulates glucose uptake in muscle and adipose cells primarily by recruiting GLUT4 from an intracellular storage pool to the plasma membrane. Dysfunction of this process known as insulin resistance causes hyperglycemia, a hallmark of diabetes and obesity. Thus the understanding of the mechanisms underlying this process at the molecular level may give an insight into the prevention and treatment of these health problems. GLUT4 in rat adipocytes, for example, constantly recycles between the cells surface and an intracellular pool by endocytosis and exocytosis, each of which is regulated by an insulin-sensitive and GLUT4-selective sorting mechanism. Our working hypothesis has been that this sorting mechanism includes a specific interaction of a cytosolic protein with the GLUT4 cytoplasmic domain. Indeed, a synthetic peptide of the C-terminal cytoplasmic domain of GLUT4 induces an insulin-like GLUT4 recruitment when introduced in rat adipocytes. Relevance of these observations to a novel euglycemic drug design is discussed.

• Nutritional Sciences
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• v.8 no.2
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• pp.97-103
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• 2005

The goal of this study was to investigate abnotmalities in camitine metabolism present by determining blood camitine and lipid concentrations in Korean diabetic patients. The study subjects included 108 Korean diabetic patients (64 males and 44 females) who were hospitalized in Chonbuk National University Hospital and 27 subjects were also hospitalized as non-diabetic controls (10 males and 17 females). Glucose, total cholesterol, triglyceride (TG) and HDL-cholesterol in plasma were enzymatically assayed and insulin was measured by immunoradiometric assay. Nonesterified camitine (NEC), acid-soluble acylcarnitine (ASAC), and acid-insoluble acylcarnitine (AIAC) were determined by a modified radioisotopic method Glucose and insulin levels were significantly elevated in diabetic patients compared with controls. Total cholesterol was elevated in female but not male diabetic patients and triglycerides were elevated both in male and female diabetics. Plasma and urinary total carnitine (TCNE) were significantly elevated in diabetics as compared with normal controls. In male diabetics, NEC concentrations were significantly elevated above controls, but not in female subjects. Plasma NEC and TCNE concentrations were significantly increased in male diabetics, but significantly decreased in female diabetics. All urinary carnitine concentrations were significantly increased in diabetics as compared with controls. Urinary NEC concentrations were four times higher in male diabetics and three times higher in female diabetics than in controls. The ratios of serum and urinary acylcarnitine/NEC were also significantly higher in diabetics than in controls. This study suggested that there was a remarkable abnormality in lipid and carnitine metabolism in Korean diabetic patients, and the further study on carnitine metabolism and the effects of carnitine supplementation for Korean diabetic patients are needed.

• Nutrition Research and Practice
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• v.6 no.3
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• pp.201-207
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• 2012

This study investigated the hypoglycemic, hypolipidemic, and antioxidant effects of dietary quercetin in an animal model of type 2 diabetes mellitus. Four-week-old C57BL/KsJ-db/db mice (n = 18) were offered an AIN-93G diet or a diet containing quercetin at 0.04% (low quercetin, LQE) or 0.08% of the diet (high quercetin, HQE) for 6 weeks after 1 week of adaptation. Plasma glucose, insulin, adiponectin, and lipid profiles, and lipid peroxidation of the liver were determined. Plasma glucose levels were significantly lower in the LQE group than in the control group, and those in the HQE group were even further reduced compared with the LQE group. The homeostasis model assessment for insulin resistance (HOMA-IR) showed lower values for LQE and HQE than for the control group without significant influence on insulin levels. High quercetin increased plasma adiponectin compared with the control group. Plasma triglycerides in the LQE and HQE groups were lower than those in the control group. Supplementation with high quercetin decreased plasma total cholesterol and increased HDL-cholesterol compared with the control group. Consumption of low and high quercetin reduced thiobarbituric acid reactive substances (TBARS) levels and elevated activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the liver. Thus, quercetin could be effective in improving hyperglycemia, dyslipidemia, and antioxidant status in type 2 diabetes.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.2
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• pp.97-101
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• 2016

Objective: Growth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities. Methods: A total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Results: Patient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups. Conclusion: Men with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.217-222
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• 2004

Feeding effects of Cordyceps militaris extract powder in rats were as follows. Triglyceride content was appeared a superior decreasing effect, total cholesterol and phospholipid content were showed relatively low decreasing effect. At this time, 3%(w/w) level of Cordyceps militaris extract powder contents was most effective to decrease these lipids content. As increasing the treating amount of Cordyceps militaris extract powder, the level of plasma glucose was decreased. But these decreasing ratio was not proportioned to the increased treating amount directly. The change of insulin level on plasma, pancreas and femur was proportioned to the plasma glucose concentration also. The Treating amount of Cordyceps militaris extract powder was very close to the decreased ratio of insulin level.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.467-476
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• 2016

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 mg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a $G_i$ inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1112-1117
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• 2012

In this study, the effects of a rice diet and bread diet on plasma triglyceride, insulin and ghrelin levels during low-intensity endurance exercise and recovery were investigated. Ten male students randomly received 2 different treatments: the rice diet and bread diet. On the first day, the participants performed 2 hours of treadmill running with 6% uphill at 50% $VO_{2max}$ after breakfast and then each consumed lunch and dinner. Blood samples were drawn 120 min before exercise and, right before exercise and, 60 min and 120 min after the start of exercise. On the second day, blood samples were drawn prior to breakfast, immediately after breakfast and, 60 min, 120 min, and 180 min after breakfast with no exercise treatment. Plasma triglyceride, ghrelin, glucose, and insulin levels were not significantly different between the two treatment groups on the first day. In addition, there was no difference in the carbohydrate and fat oxidation rate between the two treatments groups. However, plasma triglyceride levels in subjects that received the rice diet were significantly reduced by 14% when compared to subjects that received the bread diet at 180 min after consuming the breakfast diet on the second day. Ghrelin levels were significantly higher for subjects that received the rice diet than subjects that were given the bread diet. However, insulin in participants that consumed the rice diet was significantly lower than those that received the bread diet at 60 min and 120 min after consumption of the breakfast diet on the second day. Glucose levels in the subjects that were given the rice diet were significantly reduced by 10.3% when compared with participants that received the bread diet at 60 min. Therefore, the results of the study showed that a rice diet may be more effective in preventing cardiovascular diseases than a bread diet when combined with exercise.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1135-1141
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• 1999

A large number of investigations have shown that changes in nutritional condition affect endocrine status in avian species. Herein, recent findings including novel peptides discovered by the development of the techniques in the field of molecular biology have been reviewed. The insulin-like growth factors (IGF-I and IGF-II) found in chickens have been characterized and shown to be 70 and 66 amino acid polypeptides, respectively. Plasma IGF-I level is very responsive to nutrition, Le. varying dietary proteins and energy intakes, and food restriction. Plasma IGF-II concentration is altered by nutritional deprivation to a much smaller extent than plasma IGF-I concentration. Almost all of the serum and tissue IGFs are found in a complex composed of IGF and IGF-binding protein (IGFBP). In the chicken plasma, the major IGFBP differs from that in mammalian plasma. The proglucagon mRNA encodes glucagon and two glucagon-like peptides (GLP-I and GLP-2). The intracerebroventricular administration of GLP-l strongly decreased food intake of chicks, and it was indicated that the inhibition of food intake by GLP-l was associated with neuropeptide Y, which is one of the neurotransmitters reported to enhance food intake.