• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.4
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• pp.437-443
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• 1984

Muscular exercise induced by electrical stimulation of femoral nerves in perfused rat hindquarters(5 contractions per sec) in the presence of insulin and glucose effected a rapid increase(c. a. two-fold) in the level of citric acid cycle intermediates. The highest values were found within one minute of stimulation. The tissue concent ratios of lactate, pyruvate and alanine increased rapidly on initiation of exercese. Release of lactate also increased rapidly, whereas that of pyruvate was only moderately elevated. In the course of three minute exercese, the sum of alanine, glutamate and aspartate was only transiently elevated. A fall in creatine-p and ATP in the stimulated muscle was accompanied by increases in tissue level of AMP and release of ammonia into perfusing medium. However, the changes in glutamine were small. It is concluded that the pool of citric acid cycle intermediates is expanded during muscular work due (a) to an elevated level of pyruvate, leading to shifts in the levels of alanine and cycle intermediates vie trans-amination reactions and (b) to stimulation of the purine nucleotide cycle due to elevated AMP, resulting in generation of cycle intermediates and ammonia at the expense of aspartate.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.455-461
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• 2018

Deoxynivalenol (DON), a Fusarium mycotoxin, causes health hazards for both humans and livestock. Therefore, the aim of this study was to investigate the metabolic profiles of the liver, serum, and urine of piglets fed DON using proton nuclear magnetic resonance ($^1H-NMR$) spectroscopy. The $^1H-NMR$ spectra of the liver, serum, and urine samples of the piglets provided with feed containing 8 mg DON/kg for 4 weeks were aligned and identified using the icoshift algorithm of MATLAB $R^2013b$. The data were analyzed by multivariate analysis and by MetaboAnalyst 4.0. The DON-treated groups exhibited discriminating metabolites in the three different sample types. Metabolic profiling by $^1H-NMR$ spectroscopy revealed potential metabolites including lactate, glucose, taurine, alanine, glycine, glutamate, creatine, and glutamine upon mycotoxin exposure (variable importance in the projection, VIP > 1). Forty-six metabolites selected from the principal component analysis (PCA) helped to predict sixty-five pathways in the DON-treated piglets using metabolite sets containing at least two compounds. The DON treatment catalyzed the citrate synthase reactions which led to an increase in the acetate and a decrease in the glucose concentrations. Therefore, our findings suggest that glyceraldehyde-3-phosphate dehydrogenase, citrate synthase, ATP synthase, and pyruvate carboxylase should be considered important in piglets fed DON contaminated feed. Metabolomics analysis could be a powerful method for the discovery of novel indicators underlying mycotoxin treatments.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.175-180
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• 2009

Taurine is the most abundant free amino acid in the retina and transported into retina via taurine transporter (TauT) at the inner blood-retinal barrier (iBRB). In the present study, we investigated whether the taurine transport at the iBRB is regulated by oxidative stress or disease-like state in a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB) used as an in vitro model of iBRB. First, [$^3H$]taurine uptake and efflux by TR-iBRB were regulated in the presence of extracellular $Ca^{2+}$. [$^3H$]Taurine uptake was inhibited and efflux was enhanced under $Ca^{2+}$ free condition in the cells. In addition, oxidative stress inducing agents such as tumor necrosis factor-$\alpha$ (TNF-$\alpha$), lipopolysaccharide (LPS), diethyl maleate (DEM) and glutamate increased [$^3H$]taurine uptake and decreased [$^3H$]taurine efflux in TR-iBRB cells. Whereas, 3-morpholinosydnonimine (SIN-1), which is known to NO donor decreased [$^3H$]taurine uptake. Lastly, TR-iBRB cells exposed to high glucose (25 mM) medium and the [$^3H$]taurine uptake was reduced about 20% at the condition. Also, [$^3H$]taurine uptake was decreased by cytochalasin B, which is known to glucose transport inhibitor. In conclusion, taurine transport in TR-iBRB cells is regulated diversely at extracellular $Ca^{2+}$, oxidative stress and hyperglycemic condition. It suggested that taurine would play a role as a retinal protector in diverse disease states.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.785-793
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• 2013

We studied the effects of 2 different dosages of high-molecular-weight poly-${\gamma}$-glutamic acid (hm ${\gamma}$-PGA) derived from Bacillus subtilis chungkookjang on lipid metabolism in a high-fructose diet-induced hypertriglyceridemic animal model. For 4 weeks, rats were fed either AIN-93 diet (normal control, NC; n = 10) or modified AIN-93 diet in which cornstarch was substituted with 63% fructose (n = 30) to induce hypertriglyceridemia. After 4 weeks, the hypertriglyceridemic rats were treated with daily oral doses of 0 mg (hypertriglyceridemic control, HC), 2.5 mg (hypertriglyceridemic, low hm ${\gamma}$-PGA, HL), or 5 $mg{\cdot}kg{\cdot}bw^{-1}{\cdot}d^{-1}$ (hypertriglyceridemic, high hm ${\gamma}$-PGA, HH) hm ${\gamma}$-PGA for 4 weeks. The HL and HH groups exhibited significantly lower levels of serum triglyceride, total cholesterol, LDL cholesterol, and free fatty acids than the HC group. The administration of hm ${\gamma}$-PGA reduced serum ALT and AST levels. The activities of lipogenic enzymes such as hepatic malic enzyme and glucose-6-phosphate dehydrogenase as well as glucose-6-phosphate dehydrogenase mRNA expression were significantly decreased by hm ${\gamma}$-PGA administration (p < 0.05). These results indicate that hm ${\gamma}$-PGA has an anti-hypertriglyceridemic effect in high-fructose diet-induced hypertriglyceridemic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.170-176
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• 2008

This study was designed to investigate the effects of enzymatic hydrolysates (EH) from Hamcho (Salicornia herbacea L.) on blood glucose and serum lipid status in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were divided into normal and 5 diabetic groups. The diabetic groups were fed enzymatic hydrolysate-free control (DM) diets or diets supplemented with 0.02% (DM-2), 0.04% (DM-4), 0.08% (DM-8), and 0.16% (DM-16) of enzymatic hydrolysate for 4 weeks. Body weight gains were lower in five diabetic groups than that of the normal group. Blood glucose was decreased in EH-supplemented groups as compared to the normal group, and especially the lowest blood glucose levels were found in DM-4 and DM-8 groups. Activities of three disaccharidase in the middle part of the intestine, such as maltase, sucrase and lactase, in EH-supplemented groups were significantly lower than those of DM group. There was no significant differences in the activities of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) among all experimental groups. Serum triglyceride in DM group was significantly increased as compared to the normal group, but those of EH-supplemented groups were decreased to the normal level. Total cholesterol level in DM group was higher than EH-supplemented groups and normal group, but that of DM-16 group was significantly decreased to the normal level. HDL cholesterol level in DM group was significantly decreased compared to the normal group, but that of EH-supplemented groups was increased to the normal level. These results suggest that enzymatic hydrolysate from Hamcho has hypoglycemic and hypolipidemic effects on STZ-induced diabetic rats and may be useful as a dietary supplement for the treatment of diabetes.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.192-196
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• 2005

Abstract Oligotrophic microbial fuel cells (MFCs) were tested for the continuous monitoring of low biochemical oxygen demand (BOD) by using artificial wastewater, containing glucose and glutamate, as check solution. Ten times diluted trace mineral solution was used to minimize the background current level, which is generated from the oxidation of nitrilotriacetate used as a chelating agent. The feeding rate of 0.53 ml/min could increase the sensitivity from 0.16 to 0.43 ${\mu}$A/(mg BOD/l) at 0.15 ml/min. The dynamic linear range of the calibration curve was between 2.0 and 10.0 mg BOD/l, and the response time to the change of 2 mg BOD/l was about 60 min. The current signal from an oligotroph-type MFCs increased with the increase in salts concentration, and the salt effect could be eliminated by 50 mM phosphate buffer.

• The Korean Journal of Malacology
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• v.11 no.1
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• pp.51-61
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• 1995

A horizontal starch gal electrophoresis for enzyme proteins extracted from 3 species of Korean planorbid snails; Gyraulus convexiusculus, Hippeutis cantori and Segmentina hemisphaerula was carried out in order to elucidate their genetic relationships.The results from 12 enzymes employed in three different kinds of buffer systems are summarized as follows:1) Two loci from each enzyme of aldehyde oxidase, esterase, glucose phosphate isomerase. isocitrate dehydrogenase, leucine aminopeptidase, malate dehyogenase, peptidase and xanthine oxidase were detected, and only one locus was observed from each of the following four enzymes: 6-phosphogluconate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, glutamate oxaloacetate transaminase and glycerol-3-phosphate dehydrogenase.2) Most of loci in 3 species of planorbid snails employed showed homozygous and monomorphic banding patterns and some of them were specifis as genetic markers among different species. However, a few of loci (EST-1. EST-2 and GPI-2)showed polymorphic banding patterns. 3)Hippeutis cantori and Segmentina hemisphaerula were more closely clustered in a dendrogram with the genetic iddentity value of 0.431, and these two species were lineated with Gyraulus convexiusculus as another cluster at the value of 0.294.In summarizing the above results, three species of Korean planorbid snails employed in this study mostly showed monomorphic enzyme protein banding patterns and genetic differences specific among 3 species.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.165-170
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• 2007

Elevation of homocysteine levels is a risk factor for cardiovascular diseases and liver diseases. It has been reported that both streptozotocin-induced type I diabetic rats and obese type II diabetic rats have plasma total homocysteine lower than each control rats. We determined the effects of lean type II diabetes on homocysteine levels using type 2 diabetic Goto-Kakizaki rats. The concentrations of serum glucose were increased to ${\sim}two-fold$ of control levels and the total cholesterol levels were also increased in GK rats. Hepatic aspartate, histidine, threonine, alanine and methionine levels were significantly increased in GK rats. Plasma aspartate and glutamate levels were elevated, but threonine and arginine levels were decreased in GK rats. Plasma total homocysteine levels were not changed in GK rats, but hepatic total homocysteine levels were increased to ${\sim}three-fold$ of control levels. These results suggest that hepatic metabolism of sulfur-amino acid may be altered in diabetic condition.

• Journal of Applied Biological Chemistry
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• v.56 no.2
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• pp.109-112
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• 2013

Azole fungicides are one of the most wide-spread antifungal compounds in agriculture and pharmaceutical applications. Their major mode of action is the inhibition of ergosterol biosynthesis, giving depletion of ergosterol, precursors and abnormal steroids. However, metabolic consequences of such inhibition, other than steroidal metabolitesare not well established. Comprehensive metabolic profiles of Saccharomyces cerevisiae has been presented in this study. Wild type yeast was treated either with glucose as control or azole fungicide (ketoconazole). Both polar metabolites and lipids were analyzed with gas chromatography-mass spectrometry. Approximately over 180 metabolites were characterized, among which 18 of them were accumulated or depleted by fungicide treatment. Steroid profile gives the most prominent differences, including the accumulation of lanosterol and the depletion of zymosterol and ergosterol. However, the polar metabolite profile was also highly different in pesticide treatment. The concentration of proline and its precursors, glutamate and ornithine were markedly reduced by ketoconazole. Lysine and glycine level was also decreased while the concentrations of serine and homoserine were increased. The overall metabolic profile indicates that azole fungicide treatment induces the depletion of many polar metabolites, which are important in stress response.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.379-383
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• 2010

Metabolites of colorectal cancer tissues from 12 patients were analyzed and compared with those of the normal tissues by two-dimensional NMR spectroscopy. NMR data were analyzed with the help of the metabolome database and the statistics software. Cancerous tissues showed significantly altered metabolic profiles as compared to the normal tissues. Among such metabolites, the concentrations of taurine, glutamate, choline were notably increased in the cancerous tissues of most patients, and those of glucose, malate, and glycerol were decreased. Changes in individual metabolites varied significantly from patient to patient, but the combination of such changes could be used to distinguish cancerous tissues from normal ones, which could be done by PCA analysis. The traditional chemometric analysis was also performed using AMIX software. By comparing those two results, the analysis via $^1H-^{13}C$ HSQC spectra proved to be more robust and effective in assessing and classifying global metabolic profiles of the colorectal tissues.