• Animal Bioscience
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• v.34 no.4
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• pp.670-679
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• 2021

Objective: Glucose transporter 9 (GLUT9) is a uric acid transporter that is associated with uric absorption in mice and humans; but it is unknown whether GLUT9 involves in chicken uric acid regulation. This experiment aimed to investigate the chicken GLUT9 expression and serum uric acid (SUA) level. Methods: Sixty chickens were divided into 4 groups (n = 15): a control group (NC); a sulfonamide-treated group (SD) supplemented with sulfamonomethoxine sodium via drinking water (8 mg/L); a fishmeal group (FM) supplemented with 16% fishmeal in diet; and a uric acid-injection group (IU), where uric acid (250 mg/kg) was intraperitoneally injected once a day. The serum was collected weekly to detect the SUA level. Liver, kidney, jejunum, and ileum tissues were collected to detect the GLUT9 mRNA and protein expression. Results: The results showed in the SD and IU groups, the SUA level increased and GLUT9 expression increased in the liver, but decreased in the kidney, jejunum, and ileum. In the FM group, the SUA level decreased slightly and GLUT9 expression increased in the kidney, but decreased in the liver, jejunum, and ileum. Correlation analysis revealed that liver GLUT9 expression correlated positively, and renal GLUT9 expression correlated negatively with the SUA level. Conclusion: These results demonstrate that there may be a feedback regulation of GLUT9 in the chicken liver and kidney to maintain the SUA balance; however, the underlying mechanism needs to be investigated in future studies.

• 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.

• 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.

• BMB Reports
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• v.30 no.4
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• pp.240-245
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• 1997

Interactions between ganglioside $G_{M3}$ and glucose transporter, GLUT1 were studied by measuring the effect of $G_{M3}$ on steady-state and time-resolved fluorescence of purified GLUT1 in synthetic lipids and on the 3-O-methylglucose uptake by human erythrocytes. The intrinsic tryptophan fluorescence showed a GLUT 1 emission maximum of 335 nm, and increased in the presence of $G_{M3}$ by 12% without shifting the emission maximum, The fluorescence lifetimes of intrinsic tryptophan on GLUT1 consisted of a long component of 7.8 ns and a short component of 2,3 ns and $G_{M3}$ increased both lifetime components. Lifetime components were quenched by acrylamide and KI. Acrylarnide-mduced quenching of long-lifetime components was partly recovered by $G_{M3}$ However. KI-induccd quenching of short- and long-lifetime components was not rescued by $G_{M3}$. The anisotropy of 1.6-diphenyl-1.3.5-hexatriene (DPH)-probed dimyristoylphosphatidylcholine (DMPC) model membrane was also increased with $G_{M3}$ incorporation, The transport rate of 3-O-methylglucose increased by 20% with $G_{M3}$ incorporation on the erythrocytes, Therefore, $G_{M3}$ altered the environment of lipid membrane and induced the conformational change of GLUT1.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.2
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• pp.183-188
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• 2001

To elucidate antidiabetic effect and mechanism(s) of acarbose in a polygenic spontaneous hyperglycemic and hyperinsulinemic diabetic animal model, $KKA^y$ mice, acarbose was administered orally for 4 weeks and effects on body weight, plasma glucose and insulin levels, genetic expressions of intestinal sucrase-isomaltase (SI), sodium-glucose cotransporter (sGLT1) and glucose transporter in quadriceps muscle (GLUT4) were examined in this study. Although no differences in body weight were detected between control and acarbose-treated groups, plasma glucose level in acarbose-treated group was markedly reduced as compared to the control. In the mechanism study, acarbose downregulated the SI and SGLT1 gene expressions, and upregulated the GLUT4 mRNA and protein expressions when compared to the control group. In conclusion, the data obtained strongly implicate that acarbose can prevent the hyperglycemia in $KKA^y$ mice possibly through blocking intestinal glucose absorption by downregulations of SI and sGLT1 mRNA expressions, and upregulation of skeletal muscle GLUT4 mRNA and protein expressions.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.450-455
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• 2004

A reducing glucose-carrying polymer, called poly [3-O-(4'-vinylbenzyl)-D-glucose］(PVG), was interacted with HepG2 cells including a type-l glucose transporter (GLUT-1) on the cell membrane. The cooperative interaction between a number of GLUT-1s and a number of reducing 3-O-methyl-D-glucose moieties on the PVG polymer chain was found to be responsible for the increase in the interaction with HepG2 cells. The affinity between the cells and the PVG was studied using RITC-labeled glycopolymers. The specific interaction between the GLUT-1 on HepG2 cells and the PVG polymer carrying reducing glucose moieties was suppressed by the inhibitors, phloretin, phloridzin, and cytochalasin B. Direct observation by confocal laser microscopy with the use of RITC-labeled PVG and pretreatment of HepG2 cells with the inhibitors demonstrated that the cells interacted with the soluble form of the PVG polymer via GLUT-1, while fluorescence labeling of the cell surface was prevented after pretreatment with the inhibitors of GLUT-1.

• Reproductive and Developmental Biology
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• v.39 no.4
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• pp.97-104
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• 2015

Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

• 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.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.228-232
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• 2008

Antidiabetic effects of an aqueous and solvent extract prepared from the root, stem and fruit parts of Acanthopanax senticosus, were investigated in experimental Streptozotocin (STZ)-induced diabetic rats model. The n-butanol and water extracts of A. senticosus were orally administrated once a day for 6 days. The n-butanol extracts of fruit (FB) showed highest efficiency than other groups (water extracts of stem, root and fruit; butanol extracts of stem, root) on serum glucose values in the STZ-induced diabetic rats. We have studied gene expression of glucose transporter genes in C2C12 skeletal muscle cell line during differentiation treated by the n-butanol and water extracts of A. senticosus, SW, RW, FW, SB, RB and FB. The GLUT4 gene was high expressed by FB treatment. These findings suggest that FB of A. senticosus have GLUT4 gene expression activity for glucose homeostasis and may have beneficial effects on blood glucose lowering in the diabetic patients.

• BMB Reports
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• v.32 no.5
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• pp.429-435
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• 1999

Unlike the mammalian glucose transporter GLUT1, little is known about the nature of the endogenous sugar transporter(s) in insect cells. In order to establish the transport characteristics and other properties of the sugar transport proteins of Sf9 cells, a series of kinetic analyses was performed. A saturable transport system for hexose uptake has been revealed in the insect cells. The apparent affinity of this transport system(s) for 2-deoxy-D-glucose was relatively high, the $K_m$ for uptake being <0.5 mM. To further investigate the substrate and inhibitor recognition properties of the insect cell transporter, the ability of other sugars or drugs to inhibit 2-deoxy-D-glucose transport was examined by measuring inhibition constants ($K_j$). Transport was inhibited by D-mannose, D-glucose, and D-fructose. However, the apparent affinity of the C-4 epimer, D-galactose, for the Spodoptera transporter was relatively low, implying that the hydroxyl group at the C-4 position may play a role in the strong binding of glucose and mannose to the transporter. The results also showed that transport was stereoselective, being inhibited by D-glucose but not by L-glucose. It is therefore concluded that insect cells contain an endogenous glucose transport activity that in several aspects resembles the human erythrocyte glucose transporter. However, the mammalian and insect transporters were different in some of their kinetic properties, namely, their affinities for fructose and for cytochalasin B.