• Journal of Korean Biological Nursing Science
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• v.13 no.3
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• pp.245-252
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• 2011

Purpose: This study was designed to find the correlations between physical activity and insulin resistance of the middle-aged adults. Methods: One hundred thirty one subjects participated in this study were age 40-60 from Y university's center for physical exercise in W city. The data were collected from August 5 to October 5, 2009. To measure physical activity, the contracted Korean version of the Self-Report of Physical Activity Questionnaires of IPAQ was used. Insulin resistance was measured using fasting glucose levels, serum insulin levels, and HOMA method (serum insulin${\times}$fasting glucose/22.5). Results: The continuous physical activity overall in this study was on average $1,792.30{\pm}2,216.81$ MET (min/week), and as a result of categorical classification: no activity was 66 subjects (50.4%); minimum activity, 41 (31.3%); and health-improving activity, 24 (18.3%), respectively. The overall degree of insulin resistance in these subjects was $2.20{\pm}2.62$(0.28-12.74). There was negative correlation between moderate intensity activity and insulin resistance (r= -.189, p<.05). Conclusion: These results revealed that promoting moderate-intensity physical activity is important in preventing and improving insulin resistance and possibly other metabolic risk factors in the middle-aged adults.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.1
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• pp.134-140
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• 1997

Objectives of this study were to determine effects of insulin on acetyl-CoA carboxylase (ACC) activity and correlate this activity with relative amounts of ACC in MAC-T cells. MAC-T cells were grown in Medium 199 supplemented with fetal bovine serum (5%), cortisol ($1{\mu}g/ml$), and insulin ($1{\mu}g/ml$). At confuluence, the cells were transferred to $100mm^2$ culture dishes coated with the extracelluar matrix. After 10 h of incubation, the media were replaced with media without fetal bovine serum and the concentration of insulin was lowered to 5 ng/ml. After 24 h, the media were changed to contain the varying concentrations of insulin and incubations continued for 48 h. The addition of insulin resulted in increases in the specific activity of ACC. The maximal effects of insulin on the ACC activity occurred at concentrations of insulin, 1,000 ng/ml. In contrast, the relative change in lactate dehydrogenase (LDH) activity in response to increasing insulin concentration was minimal as compared to the effects of insulin on ACC. Transblot and enhanced chemiluminescence (ECL) analysis indicated that the increase in ACC activity in MAC-T cells caused by insulin were due to actual increases in amounts of enzyme.

• Proceedings of the Ginseng society Conference
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• 2006.05a
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• pp.69-70
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• 2006

Purpose: Panaxadiols are more potent than panaxatriols as far as insulin secretory activity is concerned. In this study, we examined insulin secretory activity and mechanism of compound K (CK), a major intestinal bacterial metabolite of ginsenosides. Method: Insulin secretory activity of CK was examined using pancreatic beta cells and in Oral Glucose Tolerance Test assay. In addition, insulin secretory mechanism was studied in terms of calcium dependent or independent pathways. Results: In vitro, CK enhanced the insulin secretion concentration-dependently when compared to glucose-stimulated control cells. Insulin secretory mechanism of CK seems to block ATP sensitive K channels, which was confirmed by diazoxide (K channel opener) but, insulin resistance ameliorating activity of CK can't be ruled out. In vivo, CK showed hypoglycemic effect in OGTT.

• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.25-39
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• 2010

Background : At high glucose levels in $\beta$-cells, cell viability and insulin secretion are decreased by glucotoxicity. Sopyung-tang(SPT) had an effect on blood glucose level decrease and antioxidant enzyme activities in streptozotocin-induced diabetic rats. Objectives : This study performed a series of experiment to verify the effects of SPT extract on the cell viability, antioxidant enzyme activities, insulin secretion and insulin mRNA expression at hyperglycemic states of RIN-m5F. Methods : After treatment at various concentrations of SPT added to the RIN-m5F cells, cell viability by MTT assay, free radical-scavenging activity, SOD activity and insulin secretion were measured. Additionally, insulin-related gene expression was measured using real-time RT-PCR. Results : Compared to the control group, SPT extract showed considerable effects on RIN-m5F cell viability, DPPH radical-scavenging activity, superoxide dismutase (SOD) activity, insulin secretion and insulin-related gene expression. Conclusions : This study showed that SPT extract has an effect on $\beta$-cell cell viability, insulin secretion and insulin-related gene expression. Thus, SPT extract may be used for treatment of diabetes and its complications. Further mechanism studies of SPT seem to be necessary on the glucotoxicity and oxidative stress.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.207-212
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• 2002

Acetyl-CoA carboxylase (ACC) is the enzyme that controls no devo fatty acid biogynthesis, and this enzyme catalyzes the carboxylation pathway of acetyl-CoA to malonyl-CoA. Acetyl-CoA carboxylase gene expression was regulated by nutritional and hormonal status. The present study was performed to identify the regulation mechanism of ACC gene promoter I. The fragments of ACC promoter I -1.2-kb region wert recombined to pGL3-Basic vector with luciferase as a reporter gene. The primary hepatocytes from the rat were used to investigate the hormonal regulation of ACC promoter I activity. ACC PI (-1.2)/Luc plasmid was trtransferred into primary hepatocytes using lipofectin. Activity of luciferase was increased two-fold by 10-9M, three-fold by 10-8M, 10-6M, 3.5-fold by 10-6M, and 4.5-fold by 10-7M insulin treatment, respectively. In the presence of dexamethasone (1 $\mu$M), the effects of insulin increased about 1.5-fold, showing the additional effects of dexamethasone. Moreover, the activity of luciferase increased with insulin+dexamethasone, insulin+T3, dexamethasone+T3, and dexamethasone+insulin+T3 treatment approximately 6-, 4-, 6.5-, and 10-fold, respectively. Therefore it can be postulated that 1) these hormones coordinately regulate acetyl-CoA caroxylase gene expression via regulation of promoter activity, 2) the -1.2-kb region of ACC promoter I may have the response element sequences for insulin, dexamethasone, and T3.

• BMB Reports
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• v.44 no.3
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• pp.205-210
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• 2011

Insulin has antiapoptotic activity in various cell types. However, the signaling pathways underlying the antiapoptotic activity of insulin is not yet known. This study was conducted to determine if cAMP affects the antiapoptotic activity of insulin and the activity of PI3K and ERK in CHO cells expressing human insulin receptors (CHO-IR). Insulin-stimulated ERK activity was completely suppressed by cAMP-elevating agents like as pertussis toxin (Ptx) and cholera toxin (Ctx) after 4 h treatment. Insulin-stimulated PKB/Akt activity was not affected at all. Ptx treatment together with insulin increased the number of apoptotic cells and the degree of DNA fragmentation. Ctx or 8-br-cAMP treatment also increased the number of apoptotic cells and stimulated the cleavage of caspase-3 and the hydrolysis of PARP. Taken together, cAMP antagonizes the antiapoptotic activity of insulin and the main target molecule of cAMP in this process is likely ERK, not PI3K-dependent PKB/Akt.

• Development and Reproduction
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• v.5 no.2
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• pp.101-106
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• 2001

Present study was aimed to verify the role of insulin and TNF-$\alpha$ in development of preimplantation embryos. Mouse morula were cultured for 40 hr in the presence or absence of insulin(400 ng/ml) and TNF-$\alpha$ (50 ng/ml). The morphological development, cell number of blastomeres per blastocyst, and mitogen activated protein kinase(MAPK) activity were examined. The developmental rate and cell number per embryo were the highest in insulin treatment group and the lowest in TNF-$\alpha$ treatment group. There was no significant difference in developmental rate between control and insulin plus TNF-$\alpha$ group. Taken together, it suggested that TNF-$\alpha$ impaired embryonic development and that insulin rescued developmental impairment imposed by TNF-$\alpha$. In blastocysts, insulin treatment significantly increased MAPK activity. TNF-$\alpha$ decreased the MAPK activity in a concentration-dependent manner. In the TNF-$\alpha$(50 ng/ml) -primed embryos, activation of MAPK by insulin was attenuated. In conclusion, these results suggest that there was a cross talk between insulin and TNF-$\alpha$ by means of activation of MAPK in preimplantation embryos and that insulin might rescue damage of embryos exposed to TNF-$\alpha$.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.699-712
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• 1995

The present study, to evaluate the effect of vitamin E on the oxidative stress in STZ-treated rat and BB rat, was investigated the biochemical enzyme activity in the serum, and malondialdehyde and carbonyl group in the RBC membrane, liver and microsomal fraction after vitamin E and/ or insulin treatment. Results obtained through the experiments were summarized as follows; 1. Effect of vitamin E and/or insulin treatment in STZ-treated rat 1) Lipid peroxidation level in RBC membrane, liver and microsomal fraction was significantly decreased in vi. tamin E and/or insulin treatment group, and especially more significantly decreased in vitamin E with insulin treated group. 2) Protein oxidation level in RBC membrane, liver and microsomal fraction was significantly decreased in vitamin E and/or insulin treatment group. And it was especially more significantly decreased in RBC membrane and liver of vitamin E with insulin treated group. 3) In the enzyme activity in the serum, the activity of AST and ALT was not altered in all experimental group. The increased ALP activity in STZ-treated group was significantly decreased in insulin treated group and vitamin E with insulin treated group. 4) Decreased level of albumin and creatinine after STZ treatment was significantly increased in vitamin E and/or insulin treated group. 5) Level of glucose, cholesterol and triacylglycerol in serum: Glucose level was not significantly different in vitamin E treated group compared to STZ control group. But it was significantly different in the insulin treated group and vitamin E with insulin treated group compared to STZ control group. The cholesterol content in the serum was significantly increased in STZ control group compared to normal control group. And except low dose vitamin E treatment group, it was significantly decreased in vitamin E and/or insulin treated group compared to STZ control group. The triacylglycerol content in the serum was significantly decreased in STZ control group and increased in high dose vitamin E treated group and vitamin E with insulin treated group. But it was not significantly different in low dose vitamin E treated group and insulin treated group compared to STZ control group. 2. Effect of vitamin E and/or insulin treatment in BB rat 1) Lipid peroxidation level in liver was decreased by vitamin E with insulin treatment compared to insulin treatment. But it was not different in microsomal fractions. 2) Protein oxidation level in liver and microsomal fraction was decreased by vitamin E with insulin treatment compared to insulin treatment only in microsomal fractions. These results suggest that the combination treatment of vitamin E and insulin could prevent the oxidative change of lipid and protein of the RBC membrane, liver and microsomal fraction in STZ-treated rats and BB rats.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.20-37
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• 2010

Objective: This study was performed to investigate the effect of Yagwan-cheunghyeoltang (YCT) on insulin secretion in RIN-m5F cells. Methods: After treatment with various concentrations of YCT to RIN-m5F cells, cell viability, free radical-scavenging activity, SOD activity, and insulin secretion were measured. Additionally, insulin-related gene expressions were measured using real-time RT-PCR. Results: 1. YCT didn't show any influence on RIN-m5F cells viability. 2. YCT showed free radical-scavenging activity by 16% at $100{\mu}g/m{\ell}$ of concentration. 3. YCT showed enhancement of SOD activity by 60% at $100{\mu}g/m{\ell}$ of concentration. 4. YCT significantly increased insulin secretion in RIN-m5F cells in a dose-dependent manner. 5. YCT up-regulated INS-1, INS-2, IRS-1, IRS-2 and IRS-3 mRNA expressions compared to the control group. 6. YCT down-regulated INS-R, GCK, GLP-1R and GLP-2R mRNA expressions compared to the control group. Conclusion: YCT has pharmaceutical properties enhancing insulin production and controlling glucose-associated metabolism, and could be a candidate for drug development after further research.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.258-264
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• 2004

Hypoglycemic effect of Schizandrae Fructus (SF) extract containing in Okchun-san was determined on 3T3-L1 fibroblasts and adipocytes by investigating insulin-like activity, insulin sensitizing activity and ${\alpha}-glucoamylase$ suppressing activity. SF were extracted by using 70% ethanol followed by XAD-4 column chromatography with a mixture solvent of methanol and water, and the fractional extractions were utilized for assaying hypoglycemic effect. No inhibition of ${\alpha}-glucoamylase$ activity of SF was observed. Insulin-like activity 3T3-L1 adipocytes was not shown by SF. A significant insulin sensitizing activity of SF extractions was observed in 3T3-L1 adipocytes, giving SF extractions with 1 ng/ml insulin to reach glucose uptake level increased by 50 ng/ml of insulin alone. When cells were treated with SF (Fr. 4 or 5) plus 1 ng/ml insulin, glucose uptake was increased more than seven times as compared to 1 ng/ml of insulin alone, suggesting that SF extracts increased GLUT4 content by enhancing insulin signaling. These data suggest that SF extracts (especially Fr. 4 and 5) contains an effective insulin sensitizing compounds for hypoglycemic activity in 3T3-L1 adipocytes.