• BMB Reports
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• v.51 no.9
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• pp.429-436
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• 2018

Fructose in the form of sucrose and high fructose corn syrup is absorbed by the intestinal transporter and mainly metabolized in the small intestine. However, excess intake of fructose overwhelms the absorptive capacity of the small intestine, leading to fructose malabsorption. Carbohydrate response element-binding protein (ChREBP) is a basic helix-loop-helix leucine zipper transcription factor that plays a key role in glycolytic and lipogenic gene expression in response to carbohydrate consumption. While ChREBP was initially identified as a glucose-responsive factor in the liver, recent evidence suggests that ChREBP is essential for fructose-induced lipogenesis and gluconeogenesis in the small intestine as well as in the liver. We recently identified that the loss of ChREBP leads to fructose intolerance via insufficient induction of genes involved in fructose transport and metabolism in the intestine. As fructose consumption is increasing and closely associated with metabolic and gastrointestinal diseases, a comprehensive understanding of cellular fructose sensing and metabolism via ChREBP may uncover new therapeutic opportunities. In this mini review, we briefly summarize recent progress in intestinal fructose metabolism, regulation and function of ChREBP by fructose, and delineate the potential mechanisms by which excessive fructose consumption may lead to irritable bowel syndrome.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.1-9
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• 2015

In recent years, the knowledge about bifidobacteria has considerably evolved thanks to recent progress in molecular biology. The analysis of the whole genome sequences of 48 taxa of bifidobacteria offers new perspectives for their classification, especially to set up limit between two species. Indeed, several species are presenting a high homology and should be reclassified. On the other hand, some subspecies are presenting a low homology and should therefore be reclassified into different species. In addition, a better knowledge of the genome of bifidobacteria allows a better understanding of the mechanisms involved in complex carbohydrate metabolism. The genome of some species of bifidobacteria from human but also from animal origin demonstrates high presence in genes involved in the metabolism of complex oligosaccharides. Those species should be further tested to confirm their potential to metabolize complex oligosaccharides in vitro and in vivo.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.223-229
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• 2007

The fetus is completely dependent on mother for glucose and other nutrient transfer across the placenta. At birth, when the maternal supply is discontinued, the neonate must adjust to an independent existence. The changes in the neonate's glucose homeostasis during this transition to the extrauterine environment are influenced by the mother's metabolism and intrinsic fetal and placental problems. Maturation of carbohydrate homeostasis results from a balance between substrate availability and coordination of developing hormonal, enzymatic, and neural systems. These mechanisms may not be fully developed in neonates, so the neonate is vulnerable to carbohydrate disequilibrium resulting in damage to the central nervous system. Hypoglycemia is a relatively common metabolic problem seen during newborn care. However its definition, management and long term sequalae remain controversial. Hyporglycemia occurs frequently as a transient disorder with excellent prognosis. It also may persist and recur and cause permanent neurological complications. Although the key to effective treatment of hypoglycemia is diagnostic specific, the maintenance of euglycemia is critical to the preservation of central nervous system function. This article discusses physiology of perinatal glucose homeostasis, focusing on evaluation and treatment of hypoglycemia.

• Archives of Obesity and Metabolism
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• v.3 no.1
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• pp.9-13
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• 2024

The prevalence of obesity has been increasing worldwide. Several dietary treatments have been suggested to control weight, and recent guidelines recommend individualizing the composition of macronutrients. Carbohydrates are the most important nutrients in meals, and carbohydrate restriction is a dietary strategy that promotes weight loss. A low-carbohydrate diet is effective for short-term weight loss and can help improve glycated hemoglobin, systolic blood pressure, diastolic blood pressure, and triglyceride levels; however, the long-term effects and safety of this diet remains doubtful. In the short term, there is a risk of gastrointestinal symptoms such as vomiting, diarrhea, constipation, and gastroesophageal reflux, and type 1 diabetes patients are at risk of severe hypoglycemia, while in the long term, it can lead to malnutrition and decreased exercise capacity. Thus, rather than limiting the intake of carbohydrates, it is important to limit the intake of refined grains, sugar, honey, syrup, and sweetened beverages while maintaining the planned carbohydrate intake rate and improving meal quality.

• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.1-12
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• 2019

[Purpose] The purpose of this study was to determine whether different types of carbohydrate diets with or without exercise changes energy metabolism at rest and during exercise. [Methods] To minimize differences in food and energy intake between experimental groups, mice were pairfed. After 1 week of adaptation, 40 male ICR mice (6 weeks old) were randomly divided into four groups: Sta. (high fat + high starch), Scu. (high fat + high sucrose), StaEX. (high fat + high starch + exercise), and SucEX. (high fat + high sucrose + exercise). StaEX. and ScuEX. groups underwent training by running on a treadmill five times a week. After 10 weeks of training, energy metabolism was measured for 24 h and during a 1 h exercise period. [Results] The final body weight showed no significant difference between the groups. However, the weight of abdominal tissues (epididymal, perirenal, and mesenteric adipose tissue) in training groups was markedly decreased following 10 weeks of training. Results of all energy metabolism (24 h at rest and during 1 h of exercise) showed no significant interactions between diet and exercise. A brief summary of the results of the energy metabolism is that the metabolism related indicators over 24 h were more affected by the dietary pattern than the exercise but during the 1 h of exercise, training had more effect on energy metabolism than diet. [Conclusion] Our findings confirm that: (a) the type of carbohydrates included in the diet influence the metabolic responses over 24 h, (b) training had more effect on energy metabolism than diet during 1 h of exercise, (c) both results; abdominal adipose tissue weight and fat oxidation during exercise are suggestive for a beneficial effect of moderate physical activity on weight maintenance.

• Molecules and Cells
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• v.27 no.6
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• pp.641-649
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• 2009

Pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the reversible interconversion of fructose-6-phosphate and fructose-1,6-bisphosphate, a key step in the regulation of the metabolic flux toward glycolysis or gluconeogenesis. To examine the role of PFP in plant growth, we have generated transgenic Arabidopsis plants that either overexpress or repress Arabidopsis PFP subunit genes. The overexpressing lines displayed increased PFP activity and slightly faster growth relative to wild type plants, although their photosynthetic activities and the levels of metabolites appeared not to have significantly changed. In contrast, the RNAi lines showed significantly retarded growth in parallel with the reduced PFP activity. Analysis of photosynthetic activity revealed that the growth retardation phenotype of the RNAi lines was accompanied by the reduced rates of $CO_2$ assimilation. Microarray analysis of our transgenic plants further revealed that the altered expression of $AtPFP{\beta}$ affects the expression of several genes involved in diverse physiological processes. Our current data thus suggest that PFP is important in carbohydrate metabolism and other cellular processes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.2
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• pp.77-84
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• 2000

Eight-week old perennial ryegrass (Lolium perenne L. cv. Reveille) plants were exposed to different NO3-concentrations or osmotic stress with NaCI. Previously labeled "N was chased during 14 days of non-labeled'NO3 feeding in order to investigate NO3 metabolism in relation to osmoregulation. The short termmeasurement of osmotic potential showed that the extemal concentration of Nos- had not great effect on theosmotic potential, but that osmotic adjustment was observed in NaCl-treated plants. Total uptake of NO 3 - waslargely increased by increasing supply level of NO3 while it was depressed by exposing to osmotic stress.Nitrate reduction increased to more than 29% by increasing extemal NO,- concentration from 1 mM to 10mM. When osmotically stressed with NaCI, nitrate reduction was depressed to about 37% as compared to thecontrol. The decrease in translocation of reduced N into leaves was also observed in NaCl exposed plants. Inthe medium exposed to 10 mM NO,., osmotic contribution of nitrate to cumulative osmotic potential wasdecreased, and it was osmotically compensated with soluble carbohydrate. When osmotically stressed withNaC1, the contribution of chloride was much higher than that of nitrate. The present data indicate that N03-in plant tissues, factually affected by the assimilation of this ion, plays an active role in osmotic regulation incorrelation with other osmotica such carbohydrate and chloride.(Key words : Nitrate metabolism, Osmotic stress, Nitrate supply level, Osmoregulation)ate supply level, Osmoregulation)

• Journal of Nutrition and Health
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• v.40 no.8
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• pp.675-683
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• 2007

This study was conducted to investigate the effects of feeding different carbohydrate sources and garcinia cambogia extract(HCA) on body weight and lipid metabolism. Fifty 10-month-old male Sprague-Dawley rats weighting $635{\pm}6g$ were randomly divided into 5 groups and fed different experimental diets for 4 weeks. The carbohydrate(CHO) sources of each group were cornstarch(control group, 100% of CHO), fructose(F group and FH group, 25% of CHO) and sucrose(S group and SH group, 25% of CHO). FH group and SH group were fed diets containing 1%(W/W) of HCA. Food intake, body weight gain, and calorie efficiency were not significantly different among the groups. Perirenal fat pad weight of FH group was significantly lower than F group, but epididymal fat pad weight was not different among the groups. Fasting glucose level were not significant among the groups. Plasma lipid profile of FH or SH group was slightly lower than F or S group, respectively. The degree of difference of plasma lipid level was greater between F and FH group than those of between S and SH group. In liver, total lipid, triglyceride and total cholesterol level were slightly higher in F group than S group, and tended to be lower in FH group than F group, but tended to be higher in SH group than S group. Liver citrate lyase activity were not significant among the groups. These results suggest that HCA is potential material for reduction of body weight and improvement of plasma lipid profiles. But, there was no difference between fructose intake with HCA and sucrose intake with HCA in reduction of body weight and lipid metabolism.

• Journal of Nutrition and Health
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• v.6 no.2
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• pp.1-16
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• 1973

Some effects of dietary conditions on the metabolism of nucleic acid and protein in organs of the Albino Rats have been studied. The young rats to be examined were fed on the control diet and the diets deprived of one component among protein, carbohydrate, and lipid, such as protein free diet (PF: 432 kcal/100g) carbohydrate free diet (CF: 432kcal/100g), and lipid free diet (LF: 392kcal/100g) for three, seven, and fifteen days, respectively. The contents of DNA and RNA in the liver and the brain, and also those of protein-nitrogen(PN) and nonprotein-nitrogen (NPN) in the live, the brain, and the serum have been measured. The results are as followe: 1. The contents of DNA per gram of liver were increased by feeding on protein free diet. It is concluded that the critical factor for the result is not the increase in the rates of DNA syntheses, but the decrease in the turnover rates of DNA. 2. The metabolism of DNA in the liver showed the normal status by feeding on carbohydrate free diet. On the other hand, the rates of DNA syntheses were increased by feeding on lipid free diet. 3. The rates of DNA syntheses in the brain were decreased by feeding on the unbalanced diet, such as protein free, carbohydrete free, and lipid free diet. 4. In the liver and the brain, the rates of DNA syntheses were decreased by feeding on protein free diet. But the rates showed the normal status by feeding on the carbohydrate free diet, and also showed the similar metabolism to that in the case of the control group by feeding on lipid free diet. 5. In the liver, the rates of protein syntheses were decreased, whereas the contents of nonprotein-nitrogen were increased by feeding on protein free diet. 6. In the liver and the brain, the protein syntheses showed the more increasing rates than the rates in the case of the control diet by feeding on lipid free diet. 7. In the serum, the contents of protein did not change in a short period, also the insufficient feeling on protein was examined. It is clear that in the liver the rates of protein syntheses are decreased and the rates of protein catabolism are increased, since the rates of nucleic acid syntheses are decreased by feeding on the protein free diet. On the other hand, it is considered that in the brain the turnover rates of protein does not have correlation with the rates of nucleic acid syntheses, also these are decreased by feeding on protein free diet. And also it is believed that the phenomena of homeostasis for carrying the normal metabolism of nucleic acid and protein in the liver and the brain are operated in a short period as possible, by feeding on carbohydrate free and lipid free diets.

• Journal of Korean Medicine for Obesity Research
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• v.5 no.1
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• pp.121-131
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• 2005

During last few decades dietary guidelines for the weight management mainly have focused on a low-fat, high carbohydrate diet. Carbohydrate was supposed to be low-dense, highly satiating as well as it affects little on the lipogenesis. Although low-fat diet has significant weight-reducing effect, the loss was modest and usually regained after cessation of the diet. Furthermore, low-fat, modest-carbohydrate diet did not impact on the ever increasing rates of overweight and obesity. Alternative approaches include low-carbohydrate diet, high-carbohydrate diet and low-glycemic index diet. Although none of above mentioned diet have sufficient evidence for standard weight management diet, short-term efficacy and safety are being approved continuously. Low-carbohydrate diet contains less than 45% of carbohydrate in daily energy consumption, it is claimed to have more satiating effect and to improve metabolism. However, low compliance due to the limitation of food choice should be considered on prescribing the diet. High-carbohydrate which contains 90% of carbohydrate in total daily energy consumption, is effective in providing satiety and lowering total calorie intake and cholesterol. On the other hand, nutritional unbalance should be took into account. Low-glycemic index diet is based on the theory that contemporary diet contains significantly less fiber and unrefined carbohydrate, therefore insulin secretion is disturbed. Because low glycemic index food slowly increase blood glucose and insulin level, it induces much satiating effect and may decrease calorie ultimate intake. However, poor standardization of glycemic index is one of the main obstacle for the diet to be applied in the clinic. Meanwhile, high fructose food and beverage should be discouraged because it has little satiating effect and may cause insulin resistance. High fiber food is another recommendation for healthy, lean diet.