• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.53-58
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• 1992

Hypoglycemic effect of hematoxylin was observed in streptozotocin-induced diabetic rats, of which plasma insulin levels were not affected. Investigation of hypoglycemic mechanism showed that hematoxylin stimulated glucose oxidation and glycogen synthesis in soleus muscle from diabetic rats in both basal and insulin stimulated state.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.963-971
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• 2014

This study investigated the effects of exercise intensity on PGC-$1{\alpha}$, PPAR-${\gamma}$, and insulin resistance in skeletal muscle of high fat diet-fed Sprague-Dawley rats. Forty rats were randomly divided into five groups: sedentary control group (SED), high fat diet group (HF), high fat diet+low-intensity exercise group (HFLE, 22 m/min, 60 min, 6 days/week), high fat diet+moderate-intensity exercise group (HFME, 26 m/min, 51 min), and high fat diet+high-intensity exercise group (HFHE, 30 m/min, 46 min). After 4 weeks of high fat diet and endurance exercise training, the lipid profiles, insulin, and glucose concentrations were determined in plasma. PGC-$1{\alpha}$, PPAR-${\gamma}$, and GLUT-4 contents were measured in plantaris muscle. The rate of glucose transport in soleus muscle was determined under submaximal insulin concentration ($1,000{\mu}IU/mL$ insulin, 20 min) during muscle incubation. Plasma glucose during oral glucose tolerance test in HF was significantly greater than that in SED, and plasma glucose levels in the three exercise (EX) groups were significantly lower that those in SED and HF at 30 and 60 min, respectively (P<0.05). Plasma insulin levels in the EX groups were significantly reduced by 60 min compared to that in HF (P<0.05). The protein expression level of PGC-$1{\alpha}$ as well as muscle glucose uptake were significantly higher in SED and HF than those in the three EX groups (P<0.05), and HFHE showed significantly higher levels than HFLE and HFME. Expression levels of GLUT-4 and PPAR-${\gamma}$ were significantly higher in the HFLE, HFME, and HFHE groups compared to the SED and HF (P<0.05). Therefore, the results of this study indicate that 4 weeks of high fat diet significantly developed whole body insulin resistance but did not affect PGC-$1{\alpha}$, PPAR-${\gamma}$, or the glucose transport rate in skeletal muscle, and exercise training was able to attenuate deteriorated whole body insulin resistance due to high fat diet. In addition, high intensity training significantly affected PGC-$1{\alpha}$ expression and the glucose transport rate of skeletal muscle in comparison with low and middle training intensities.

• Clinical and Experimental Pediatrics
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• v.63 no.3
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• pp.110-114
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• 2020

Background: Subclinical hypothyroidism (SH) is a common condition in obese children. However, its effect on glucose and lipid metabolism in obese children remains controversial. Purpose: The present study aimed to investigate the association between SH and metabolic parameters. Methods: A total of 215 obese children and adolescents aged 6-18 years were included in this retrospective cross-sectional study. The patients' anthropometric measurements such as thyrotropin (TSH), free thyroxine (fT4), fasting plasma glucose, and insulin levels, as well as homeostasis model assessment for insulin resistance (HOMA-IR) index, and lipid profiles were evaluated. The patients were allocated to the SH group (fT4 normal, TSH 5-10 mIU/L) (n=77) or the control group (fT4 normal, TSH<5 mIU/L) (n=138). The glucose and lipid metabolisms of the 2 groups were compared. Results: SH was identified in 77 of 215 patients (36%). Mean body mass index was similar in both groups. The mean serum insulin, HOMA-IR, and triglyceride (TG) levels were higher and the mean high-density lipoprotein cholesterol level was lower in the SH group than in the control group (P=0.007, P=0.004, P=0.01, and P=0.02, respectively). A positive correlation was observed between TSH level and insulin level, HOMA-IR, and TG level. Conclusion: SH was identified in some of the obese children and adolescents. A clear association was observed between SH, insulin resistance, and dyslipidemia in obese children.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.342-346
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• 1999

This study was performed to investigate the effect of cyclosporine (CsA) on glucose tolerance and peripheral insulin sensitivity in normal Sprague-Dawley rats. After daily treament of CsA (10 mg/kg, i.p.) for two weeks, glucose tolerance tests were carried out by the treatment of glucose (Glu, 2 g/kg, i.p.) alone or in conjunction with exogenous insulin (Ins; human regular insulin, 5 U/kg, s.c.) and measured the decrement of area under the time-plasma glucose concentration curve ($AUC_{o\longrightarrow120}$; g.min/ml) by the trapezoidal rule. The rats were divided into three groups (Glu- (Control), Ins+Glu- and CsA+Ins+Glu-, n=7 in each group). The $AUC_{o\longrightarrow120}$ of the CsA+Ins+Glu-group was significantly (p<0.01) lower than that of Glu-group (61.0% of control) and significantly (p<0.05) higher than that of Ins+Glu-group (197.4% of Ins+Glu-). The CsA+Ins+Glu- grou showed higher levels of maximal blood glucose concentration and higher $AUC_{o\longrightarrow120}$ than those of Ins+Glu-group in normal rats. Besides direct pancreatic toxicity of CsA previously reported (Hahn et al., 1972), these results suggest that CsA also make the possibility to induce peripheral insulin insensitivity and glucose intolerance in normal rats.

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.712-716
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• 2000

The Purpose of this study is to investigate the effect of soluble dietary fiber psyllium on insulin sensitivity and skeletal muscle glucose transporter 4(GLUT4) protein expression in stroke-prone hypertensive rats(SHRSP) fed a high-fat diet containing 5% of psyllium or cellulose from five to nine weeks of age. Obtained results were as follows : (1) In the psyllium diet group fasting plasma glucose level was significantly reduced and glucose levels upon oral glucose tolerance test were significantly lower than cellulose diet group at 30 min(p<0.05) and 60 min(p<0.01) (2) Skeletal muscle GLUT4 contents were significantly increased in the soleus(slow twitch) and extensor digitorum longus(fast twitch) muscle of psyllium diet group. (3) However there was no difference in insulin levels in the fasting and oral glucose tolerance test. These results indicated that psyllium diet improves peripheral insulin sensitivity but not insulin secretion. In conclusion our present finding suggest that soluble fiber diet is effective to increase insulin sensitivity in SHRSP. From these results it was suggested that soluble dietary fiber supplementation effectively prevents insulin resistance.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.205-210
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• 2007

The objectives of the study were (1) To evaluate the safety and tolerability of Damtab. (2) To characterize hypoglycemic effect of Damtab, if any. (3) To evaluate insulin sensitivity effect of Damtab, if any. Hypoglycemic effect of Damtab (700 mg and 1,400 mg) were examined. Gliclazide (80 mg) was used as an active control. Placebo was used as control. Breakfast was given, half an hour before dosing whereas lunch, snacks and dinner were given at 6, 10 and 14 h post dose. An oral glucose tolerance test was conducted to calculate the insulin sensitivity index from the values of glucose and insulin during oral glucose tolerance test. Both giclazide 80 mg and Damtab 1,400 mg significantly lowered plasma glucose level up to 6 h. Insulin sensitivity index of Damtab (1,400 mg) was found to be similar to that of placebo. A significant increase in insulin level at 1 h post dose of Damtab (1,400 mg) was observed. Damtab 700 mg shows placebo like effect whereas Damtab 1,400 mg possesses hypoglycemic effect.

• Journal of Life Science
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• v.31 no.8
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• pp.729-735
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• 2021

Type 2 diabetes occurs when there is an abnormality in the tissue's ability to absorb glucose. Glucose uptake and metabolism by insulin are the basic mechanisms that maintain blood sugar. Glucose uptake goes through various signaling steps initiated by the binding of insulin to receptors on the cell surface. In line with the foregoing, the purpose of this study was to investigate the effect of 2,7-phloroglucinol-6,6-bieckol (PHB), an active compound isolated from Ecklonia cava, on glucose uptake in 3T3-L1 adipocytes. Notably, PHB increased glucose uptake in a dose-dependent manner owing to the enhanced glucose transporter type 4 (GLUT4) expression in the plasma membrane of 3T3-L1 adipocytes. These effects of PHB were attributed to the phosphorylation of insulin receptor substrate-1 and protein kinase B (PKB or AKT), as well as to the phosphoinositide 3-kinase (PI3K) activation in the insulin signaling pathway. PHB also stimulated 5' AMP-activated protein kinase (AMPK) phosphorylation and activation. The phosphorylation and activation of the PI3K/AKT and AMPK pathways by PHB were identified using wortmannin (a PI3K inhibitor) and compound C (an AMPK inhibitor). In this study, we showed that PHB can increase glucose uptake in 3T3-L1 adipocytes by promoting GLUT4 translocation to the plasma membrane via the PI3K and AMPK pathways. The results indicate that PHB may help improve insulin sensitivity.

• Journal of Korean Physical Therapy Science
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• v.9 no.4
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• pp.45-52
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• 2002

Rats that are fed a fructose-rich diet develop hypertension, insulin resistance, and hypertriglyceridemia. To elucidate whether altered expression levels of endothelin-1 and nitric oxide synthase are related to the development of insulin-resistant hypertension, we examined the present study. Male Sprague-Dawley rats were fed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid and plasma nitrite/nitrate levels did not significantly differ between the fructose-fed and control groups, plasma insulin and serum triglyceride concentrations significantly increased in the former. Endothelin-1 mRNA expression in the aorta increased in fructose-fed rats. Neither the protein expression of constitutive nitric oxide synthase nor that of inducible nitric oxide synthase were significantly affected by fructose feeding. However, nitrite/nitrate levels in the aorta were significantly increased. These results suggest that an increase in vascular endothelin-1 is an important contributing factor to the development of hypertension in fructose-fed rats. However, the vascular nitric oxide pathway may not be causally related to the development of fructose-induced hypertension.

• The Korean Journal of Food And Nutrition
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• v.16 no.2
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• pp.146-151
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• 2003

Chinese medical materials of Astragalas manbranaceus Bunge, Angelica gigas Nakai, Cnidium officinale, Glycyrrhiza uralensis Fisch, Lycium Chinese Mill were mixed, mixing ratio was 28:20: 18:18:16(w/w). Yield and concentration of extract obtained through extraction- concentration process of the mixed Chinese medical materials were 37.28%(w/w) and 50Brix, respectively. Animal feed(AF) used for animal test was manufactured from both mixing of general AF and this extract(0∼ 5%, w/w) and freeze dried. After the male rats were fed experimental diets in order to test during 4 weeks, the results of plasma TG, total cholesterol, phospholipid content changes and plasma, pancreas and femur insulin concentration changes were followed. The more the amount of treatment of Chinese medical material extract are, the higher the effect of concentration decline are in plasma lipid concentration. And at 3% treatment plasma TG, total cholesterol and phospholipid contents are decreased respectively 8.62%, 2.81% and 2.11%. Plasma glucose concentration has also similar effect that those things are decreased at 3% treatment. Insulin concentration of plasma, pancreas and femur are difficult to prove the effects due to respective increase and decrease. We guess that these results comes from not experimenting intentioned rat of diabetes mellitus but normal rat.

• Korean Journal of Community Nutrition
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• v.4 no.1
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• pp.103-110
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• 1999

The purpose of this study was to determine the effects of taurine supplementation and taurine depletion on blood glucose and blood lipid concentrations in insulin-treated diabetic rats. Four groups of Sprague-Dawley male rats were fed the purified diet for 3 weeks ; nontaurine-supplemented diabetic rats(E0), nontaurine-supplemented diabetic rats with insulin treatment(E0＋I), 1% taurine-supplemented diabetic rats with insulin treatment(E1＋I) and taurine-depleted diabetic rats with insulin treatment(EA＋I). Diabetes was induced by streptozotocin injection(50mg/kg B.W.). Isophane insulin was given subcutaneously into the abdominal wall of the diabetic rats(4 unit/rat/day). E1＋I were supplemented with 1% taurine in drinking water. To induce taurine depletion, EA＋I were treated with 5% $\beta$-alanine in drinking water. E1＋I had significantly higher body weight compared to that of E0. The food intakes of E1＋I and E0＋I were significantly decreased compared to that of E0. There was no sigfniciant difference in food intake between E1＋I and E0＋I. The water intake of rats was significantly different among the groups ; E0>E0＋I>E1＋I>EA＋I. The urine volume of E0 was significantly increased compared to those of insulin-treated goups. The blood glucose concentration of E0 was significantly increased compared to those of insulin-treated groups. In the oral glucose tolerance test(OGTT), E0＋I and E1＋I had significantly lower blood blucose concentrations compared to E0 after 30 min. Also EA＋I had significantly lower bloodglucose concentrtion compared to E0 and E0＋I. The plasma total cholesterol and LDL-cholesterol concentratons of EA＋I were significantly incrased compared to those of other groups. Therefore, it may be suggested that tuarine supplementation is useful for insulin-dependent diabetes in order to prevent diabetic complications suchas cardiac vascular diseases.