• The Korean Journal of Physiology and Pharmacology
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• 제28권1호
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• pp.31-38
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• 2024

As in type 1 diabetes, the loss of pancreatic β-cells leads to insulin deficiency and the subsequent development of hyperglycemia. Exercise has been proposed as a viable remedy for hyperglycemia. Lithium, which has been used as a treatment for bipolar disorder, has also been shown to improve glucose homeostasis under the conditions of obesity and type 2 diabetes by enhancing the effects of exercise on the skeletal muscles. In this study, we demonstrated that unlike in obesity and type 2 diabetic conditions, under the condition of insulin-deficient type 1 diabetes, lithium administration attenuated pancreatic a-cell mass without altering insulin-secreting β-cell mass, implying a selective impact on glucagon production. Additionally, we also documented that lithium downregulated the hepatic gluconeogenic program by decreasing G6Pase protein levels and upregulating AMPK activity. These findings suggest that lithium's effect on glucose metabolism in type 1 diabetes is mediated through a different mechanism than those associated with exercise-induced metabolic changes in the muscle. Therefore, our research presents the novel therapeutic potential of lithium in the treatment of type 1 diabetes, which can be utilized along with insulin and independently of exercise.

• 한국양식학회지
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• 제19권4호
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• pp.315-322
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• 2006

본 연구에서는 담수사육 감성돔을 대상으로 수온을 상승시켰을 때, 세포적 스트레스 측면에서 HSP90 및 HSP70 mRNA의 발현 정도를, 신경-내분비적 스트레스 측면에서 혈장 cortisol 및 glucose 농도를 조사하였다. RT-PCR법을 이용하여 생식소로부터 HSP90 (891 bp) 및 HSP70 (465 bp) cDNA 단편을 클로닝 하여, 타 종과 그 상동성을 비교해 본 결과, 감성돔 HSP90은 참돔 HSP90과 99%, 무지개송어 HSP90과 95%, 대서양 연어HSP90과 94%, zebrafish HSP90과 94%로 나타났으며, 감성돔 HSP70은 무지개송어 HSP70과 96%, silver seabream HSP70과 95%, zebrafish HSP70과 95%의 상동성을 나타내었다. 감성돔의 사육수온을 $30\;^{\circ}C$로 상승시켰을 때, HSP90 mRNA는 모든 조직에서 그 발현 정도가 $20\;^{\circ}C$ 실험구에 비하여 $7{\sim}9$배 정도 높았으나, HSP70 mRNA는 생식소에서만 발현하는 것으로 나타났다. 혈장 cortisol 및 glucose 농도는 $20\;^{\circ}C$ 실험구에 비하여 $30\;^{\circ}C$ 실험구에서 유의하게 증가한 것으로 나타났다.

• 대한임상전기생리학회지
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• 제1권1호
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• pp.73-85
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• 2003

The purpose of this study is to discuss and analyze the change of GLUT-4 and muscle fiber type of streptozotocin(STZ)-diabetic rats over a period of 6 weeks. We divided into four groups; I(aquatic exercise and feeding of Cordyceps militaris; n=6), test group II(feeding of Cordyceps miliaris; n=6), test group III(aquatic exercise; n=6), control group IV(non-treatment; n=6). After experimenting we measured the blood glucose, body weight, muscle fiber type and GLUT-4 protein content. The change of glucose levels decreased greater in group I than the other group. The body weight gain was lower in the all groups. The change femoris muscle fiber type, the size of muscle fiber TypeII lessened more than the one of Type I in group IV. Decrease of muscle fiber size more diminishment in group I than the other group. GLUT-4 protein quantity decrease in group IV compared to normal group. It was significantly increased in group. I, III compared to group IV. But there was more increase in group I (p<.001). These results suggest that GLUT-4 and muscle fiber type II decrease in STZ-diabetic rats and that when we apply aquatic exercise and feeding of Cordyceps militaris in diabetic rats over a period 6 weeks, it is increase GLUT-4 and the increase of insulin sensitivity of peripheral tissue. So it is considered to be helpful in improvement of glucose homeostasis and in prevent from muscle atrophy resulted from complication.

• Nutrition Research and Practice
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• 제10권5호
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• pp.501-506
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• 2016

BACKGROUNG/OBJECTIVES: Corn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets. MATERIALS/METHODS: Normal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor ${\alpha}$ were determined. RESULTS: Oral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different. CONCLUSIONS: CS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.

• Nutrition Research and Practice
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• 제8권5호
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• pp.544-549
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• 2014

BACKGROUND/OBJECTIVES: Obesity-associated insulin resistance is a strong risk factor for type 2 diabetes mellitus. The aim of this study was to investigate the effect of myricetin on adiposity, insulin resistance, and inflammatory markers in mice with diet-induced insulin resistance. MATERIALS/METHODS: Five-week-old male C57BL/6J mice were fed a basal diet, a high-fat, high-sucrose (HFHS) diet, or the HFHS diet containing 0.06% myricetin or 0.12% myricetin for 12 weeks after a 1-week adaptation, and body weight and food intake were monitored. After sacrifice, serum lipid profiles, glucose, insulin, adipocyte-derived hormones, and proinflammatory cytokines were measured. The homeostasis model assessment for insulin resistance (HOMA-IR) was determined. RESULTS: Myricetin given at 0.12% of the total diet significantly reduced body weight, weight gain, and epidydimal white adipose tissue weight, and improved hypertriglyceridemia and hypercholesterolemia without a significant influence on food intake in mice fed the HFHS diet. Serum glucose and insulin levels, as well as HOMA-IR values, decreased significantly by 0.12% myricetin supplementation in mice fed the HFHS diet. Myricetin given at 0.12% of the total diet significantly reduced serum levels of leptin, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) in mice fed the HFHS diet. CONCLUSIONS: These findings suggest that myricetin may have a protective effect against diet-induced obesity and insulin resistance in mice fed HFHS diet, and that alleviation of insulin resistance could partly occur by improving obesity and reducing serum proinflammatory cytokine levels.

• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.1-7
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• 2009

Control of hyperglycemia and dyslipidemia is strongly correlated with decreased risk for cardiovascular disease, the most common and fatal diabetic complication. The purpose of this study is to determine the effects of garlic and aged black garlic on glycemic control and blood lipid profile in animal model of type 2 diabetes. Three week-old db/db mice (C57BL/Ks, n=21) were fed AIN-93G semipurified diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Fasting serum glucose, insulin, triglyceride, total cholesterol, and HDL-cholesterol and blood glycated hemoglobin were measured. Body weight and food intake of garlic and aged black garlic group were not significantly different from those of the control group. Fasting serum glucose and blood glycated hemoglobin levels were significantly decreased and insulin level was significantly increased in garlic group compared with control group (p<0.05). Consumption of aged black garlic significantly decreased homeostasis model assessment for insulin resistance (HOMA-IR) and tended to decrease serum glucose. Garlic consumption significantly decreased total cholesterol, while aged black garlic significantly reduced serum total cholesterol and triglyceride and increased HDL-cholesterol levels. These results suggest that garlic exerts hypoglycemic and hypocholesterolemic effect and aged black garlic improved insulin sensitivity and dyslipidemia in db/db mice.

• 한국식품조리과학회지
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• 제30권4호
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• pp.369-377
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• 2014

Obesity increases oxidative stress, which could contribute to the development of insulin resistance and hyperglycemia. The purpose of this study was to investigate the hypoglycemic and antioxidant effect of sanchae-namul (SN) in mice with diet-induced obesity. Five-week-old male C57BL/6J mice were fed a basal or high-fat and high-sucrose (HFHS) diet with or without 3% freeze-dried SN powder composed of chamnamul, daraesoon, miyeokchwi, bangpung namul, and samnamul for 12 weeks after a 1-week adaptation. After sacrifice, serum glucose and insulin were measured and the homeostasis model assessment for insulin resistance (HOMA-IR) was determined as well. Hepatic lipid peroxidation, glutathione (GSH), and activities of the antioxidant enzymes were determined. SN given at 3% of the total diet did not significantly influence body weight and food intake in mice fed the HFHS diet. Serum glucose and insulin levels, as well as HOMA-IR values, were significantly lower in the SN group than those in the HFHS group. Thiobarbituric acid reactive substances (TBARS) levels in the liver were decreased significantly in the SN group compared with those in the HFHS group. SN significantly increased the GSH levels and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the liver compared with those in the HFHS group. Overall, these findings suggest that SN may be useful in alleviating insulin resistance and hyperglycemia in mice fed HFHS diet; further, the improvement of insulin resistance could partly occur by reducing the oxidative stress.

• Nutrition Research and Practice
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• 제6권3호
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• pp.221-225
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• 2012

Zinc deficiency is known to be associated with insulin resistance in obese individuals. This study was performed to evaluate the effect of zinc supplementation on insulin resistance and metabolic risk factors in obese Korean women. Forty obese women (body mass index (BMI) ${\geq}25kg/m^2$) aged 19-28 years were recruited for this study. Twenty women of the study group took 30 mg/day of supplemental zinc as zinc gluconate for 8 weeks and 20 women of control group took placebo. Usual dietary zinc intake was estimated from 3-day diet records. Insulin resistances were measured using Homeostasis model assessment (HOMA) indices, and insulin sensitivities Matsuda indices, which were calculated using oral glucose tolerance test data. Metabolic risk factors, such as waist circumference, blood pressure, fasting glucose, triglyceride, high density lipoprotein (HDL) cholesterol, and adipocyte hormones such as leptin, and adiponectin were also measured. At the beginning of study, dietary zinc averaged 7.31 mg/day and serum zinc averaged $12.98{\mu}mol/L$ in the study group. Zinc supplementation increased serum zinc by 15% and urinary zinc by 56% (P < 0.05). HOMA values tended to decrease and insulin sensitivity increased slightly in the study group, but not significantly so. BMI, waist circumference, blood pressure, blood glucose, triglyceride, HDL cholesterol, and adipocyte hormones did not change in either the study or control group. These results suggest that zinc status may not affect insulin resistance and metabolic risk factors in obese Korean women. Further research is required on a larger cohort with a longer follow-up to determine the effects of zinc status on insulin resistance and metabolic variables.

• BMB Reports
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• 제44권11호
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• pp.713-718
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• 2011

In this study, the effects of sitagliptin analogue (SITA) or pioglitazone (PIO) treatment on glucose homeostasis and ${\beta}$-cell dynamics in animal models of type 2 diabetes-Akita and db/db mice were evaluated. After 4-6 weeks of treatment, both SITA and PIO were shown to lower non-fasting glucose levels and reduced glycemic excursion in the intraperitoneal glucose tolerance test. In addition, both drugs preserved normal islet structure and the proportion of ${\beta}$-cells in the islets. Compared to the controls, SITA treatment induced a higher ${\beta}$-cell proliferation rate in Akita mice and a lower rate of apoptosis in db/db mice, whereas PIO treatment induced a lower rate of apoptosis in db/db mice and reduced proliferation rates in Akita mice. In conclusion, both SITA and PIO appear to exert some beneficial effects on the islet structure in addition to glycemic control via different mechanisms that involve ${\beta}$-cell dynamics in Akita and db/db mice.

• Clinical and Experimental Pediatrics
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• 제60권11호
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• pp.359-364
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• 2017

Purpose: The risk of cardiovascular disease (CVD) has been shown to be associated with systemic inflammation in obese adults with metabolic syndrome (MetS). The aims of this study were to evaluate the prevalence of MetS and its relation to inflammatory markers in obese Thai children. Methods: A cross-sectional study was conducted. Children with history of endogenous obesity, chronic diseases, drug ingestion, and any acute illness within 2 weeks prior to enrollment were excluded. Their fasting blood glucose (FBG) levels, oral glucose tolerance tests, insulin, lipid profiles, and selected inflammatory markers, including interleukin-6, tumor necrosis factor-alpha, and high-sensitivity C-reactive protein (hs-CRP) levels, were tested. Results: In this study, 58 obese Thai children (female, 20; male, 38) with a mean body mass index z score of $5.1{\pm}2.2$ were enrolled. The prevalence of MetS and prediabetes was 31% and 17.2%, respectively. None of the children had diabetes. FBG levels, 2-hour glucose levels, and lipid profiles were not statistically different between those with and without MetS. However, obese children with MetS had higher insulin levels and homeostasis model assessment of insulin resistance values. Elevated hs-CRP levels were found in 69% of the cases, although it was not statistically different between the 2 groups. Conclusion: We described a substantial prevalence of MetS in Thai obese children. Regardless of MetS status, two-thirds of the obese children had elevated hs-CRP level, indicating subtle ongoing inflammatory process. This chronic inflammation feasibly predisposes them to CVD in the future, even in children without MetS.