• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.104-108
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• 1998

Analysis of energy budget in Neomysis awatschensis exposed to PCB toxicity was carried out by measurement of bioassay, growth, oxygen consumption, nitrogen excretion at 10 and $20^{\circ}C$. Energy contents of the body, molted exoskeleton and eggs, which measured to understand used energy for growth, molt and oxygen consumption were 5.52cal/mg, 2.17 cal/mg and 6.15 cal/mg, respectively. Feeding energies at $10^{\circ}C$ were 3.755ca1 in control group and 3.420 cal at 2.0 ppb concentration, of them, $70.19\%$ and $67.53\%$ of their energies were assimilated. At $20^{\circ}C$, feeding energies were 5.998 cal in control group and 4.166 cal at 2.0 ppb concentration. The assimilation efficiency of the mysid estimated by ash-ratio method ranged between $11.5\~67.5\%$ and $73.4\~70.5\%$ with PCB toxicity at $10^{\circ}C$ and $20^{\circ}C$ respectively. Energy used by respiration of total assimilated energy was $45.18\%$ in control group and $62.27\%$ in 2.0 pub concentration at $20^{\circ}C$, and energy used by metabolism was high 2.0 ppb concentration than control group.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.80-90
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• 2004

Three experiments were performed to test the assumption that imbalanced dietary amino acid mixtures must lead to increased heat production (HP). The first experiment was based on diets formulated to have a wide range of crude protein (CP) concentrations but a fixed concentration of lysine, formulated to be the first-limiting amino acid. In the second (converse) experiment, lysine concentration was varied over a wide range while CP content was kept constant. To prevent the masking of dietary effects by thermoregulatory demands, the third experiment was performed at 30 $^{\circ}C$ with the diets similar to the diets used in the second experiment. The detailed relationships among amino acid balance, nitrogen (N) metabolism and energy (E) metabolism were investigated in a computer-controlled chamber calorimetry system. The results of experiments were compared with the predictions of a computerised simulation model of E metabolism. In experiment 1. with constant lysine and varying CP, there was a 75 % increase in N intake as CP concentration increased. This led to a 150 % increase in N excretion. with no significant change in HP. Simulated HP agreed with the empirically determined results in not showing a trend with dietary CP. In experiment 2, with varying lysine but constant CP, there was a 3-fold difference in daily weight gain between the lowest and highest lysine diets. HP per bird increased significantly with dietary lysine concentration. There was still an effect when HP was adjusted for body weight differences, but it failed to maintain statistical significance. Simulated HP results agreed in showing little effect of varying lysine concentration and growth rate on HP. Based on the results of these two experiments, the third experiment was designed to test the response of birds to dietary lysine in high ambient temperature. In experiment 3 which performed at high ambient temperature (30 $^{\circ}C$), HP per bird increased significantly with dietary lysine content, whether or not adjusted for body-weight. The trend was greater than in the previous experiment (20 $^{\circ}C$).

• Journal of Life Science
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• v.30 no.2
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• pp.211-220
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• 2020

The activity of CAR can be regulated not only by ligand binding but also by phosphorylation of regulatory factors involved in extracellular signaling pathways, cross-talk interactions with transcription factors, and the recruitment, degradation, and expression of coactivators and corepressors. This regulation of CAR activity can in turn have effects on the control of diverse physiological homeostasis, including xenobiotic and energy metabolism, cellular proliferation, and apoptosis. CAR is phosphorylated by the ERK1/2 signaling pathway, which causes formation of a complex with Hsp-90 and CCRP, leading to its cytoplasmic retention, whereas phenobarbital inhibits ERK1/2, which causes dephosphorylation of the downstream signaling molecules, leading to the recruitment to CAR of the activated RACK-1/PP2A components for the dephosphorylation, nuclear translocation, and the transcriptional activation of CAR. Activated CAR cross-talks with FoxO1 to induce inhibition of its transcriptional activity and with PGC-1α to induce protein degradation by ubiquitination, resulting in the transcriptional suppression of PEPCK and G6Pase involved in gluconeogenesis. Regulation by CAR of lipid synthesis and oxidation is achieved by its functional cross-talks, respectively, with PPARγ through the degradation of PGC-1α to inhibit expression of the lipogenic genes and with PPARα through either the suppression of CPT-1 expression or the interaction with PGC-1α each to induce tissue-specific inhibition or stimulation of β-oxidation. Whereas CAR stimulates cellular proliferation by suppressing p21 expression through the inhibition of FoxO1 transcriptional activity and inducing cyclin D1 expression, it suppresses apoptosis by inhibiting the activities of MKK7 and JNK-1 through the expression of GADD45B. In conclusion, CAR is involved in the maintenance of homeostasis by regulating not only xenobiotic metabolism but also energy metabolism, cellular proliferation, and apoptosis through diverse cross-talk interactions with extracellular signaling pathways and intracellular regulatory factors.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.299-306
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• 1996

The effects of antimetabolite 6-aminonicotinamide on levels of soluble proteins, free amino acids and protease activity in various tissues of quail have been in vestigated. The levels of soluble proteins m liver, heart and pectoral muscle were markedly lowered and the specific activity of protease in kidney and pectoral muscle was markedly increased. The concentrations of aspartic acid / asparagine, alanine, valine, methionine, isoleucine, leucine and lysine in the liver were markedly increased. En the kidney the concentrations of aspartic acid I asparagine, arginine, threonine, alanine, proline and lysine were markedly increased but those of glutamic acid I glutamine were decreased. The concentrations of glutamic acid / glutamine and serine in the heart were reduced but those in glycine and methionine were increased. In the pectoral muscle the concentration of arginine was decreased but the concentration of alanine and threonine was increased. The overall results suggest that antimetabolite 6-aminonicotinamide may act to enhance concentrations of amino acids related to the generation of energy and to depress the biosynthesis of some specific amino acids.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.391-397
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• 2016

Clostridium is a genus of Gram-positive, rod shape, spore-forming obligate anaerobe. Recently, Clostridium has been attracted as a host for bio-based chemical production, due to its diversity of substrate utilization and the production ability for metabolites which can be used as a building block for chemical production. Especially, butanol produced from Clostridium has been considered as an alternative fuel. As a transportation fuel, butanol has a higher energy density and lower hygroscopicity compared to ethanol, the first generation biofuel. Recently, metabolic engineering of Clostridium has been massively conducted for butanol production. In this study, the metabolic engineering strategy of Clostridium for butanol production has been reviewed with a brief perspective.

• Journal of Life Science
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• v.28 no.1
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• pp.1-8
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• 2018

To confirm the function of lactate dehydrogenase (LDH) (EC 1.1.1.27, LDH), its metabolism was studied by activity, kinetics, and isozyme analysis in tissues of Ldh testis-specific C expressing mice (Mus musculus) maintained in a state of starvation for 48 hr and 96 hr. In skeletal muscle, liver, and eye tissues, LDH and LDH $A_4$ activity increased and anaerobic metabolism predominated. While LDH activity in the heart and kidney tissues decreased, LDH $B_4$ activity increased and aerobic metabolism predominated, producing pyruvic acid. In the testis tissue, LDH $C_4$ activity decreased. In the brain tissue, LDH activity increased, but the isozyme change was small and the amount of pyruvic acid decreased. $K{_m}^{PYR}$ increased in tissues other than kidney tissue, and the affinity for pyruvic acid decreased. Consequently, in Ldh-A and B-expressing tissues, the activities of isozymes with higher concentrations increased. However, in Ldh-A, B, and C-expressing tissue, $C_4$ decreased and the function of the tissue also decreased. In particular, LDH in brain tissue played a role as a pyruvate reductase. Therefore, this process might be the mechanism for producing energy in the state of starvation.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.57-63
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• 1993

The abilities of metabolic substrates, glucose, pyruvate, and acetate to produce a maximal increase in the force of contraction of substrate-depleted atria from fed rats were compared to those from starved rats, in order to observe the effect of starvation on substrate utilization of the myocardium. Starvation results in a marked loss of body weight in rats. In contrast to the starved rats, the body weight of fed rats increased with time. When placed in substrate-free medium, atria from fed rats showed marked decline in contractile force. In contrast to the atria from fed rats, the substrate-depleted atria from starved rats showed much less decline of the force of contraction. In the substrate-free medium, abilities of glucose, pyruvate, and acetate to produce a maximal increase in the force of contraction of atria from fed rats were much greater than those from starved rats. The data from these studies indicate that in the substrate-free medium atria from starved rats utilize much less exogenous substrates than those from fed rats. These results suggest that starvation has no deleterious effect on contractile activity of the myocardium, and the starvation increase the storage of readily metabolizable endogenous substrstes useful for the functional activity of the isolated heart.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1145-1155
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• 2018

The purpose of this study was to investigate the effect of dietary restriction(DG), aerobic exercise(EG), dietary restriction with aerobic exercise(DEG) on weight, improvement of obesity, blood lipid profiles and metabolic risk factors of obese female college students. Experiments was conducted 5 times a week for 8 weeks. DG spent 300kcal/day, and EG used 300kcal/day to run, DEG each consumed 150kcal/day limits. As s result, in case of body composition, weight(p<.011) and BMI(p<.008) were decreased in DG group, and weight(p<.044, p<.017), body fat(p<.047, p<.018), BMI(p<.03, p<.008), body fat%(p<.036, p<.015) and WHR(p<.049, p<.027) were decreased in EG and DEG groups. In case of blood lipid profiles's change, there are some differences on TC(p<.006), TG(p<.047) according to the time. In DG:HDL-C(p<.028), in EG:TG(p<.038), in DEG:TC(p<.014), LDL-C(p<.007) have decreased. In case of metabolic risk factor's change, there are some differences on FBG(p<.001), insulin(p<.004), HOMA-IR(p<.001), leptin(p<.000), adiponectin(p<.038), resistin(p<.010) according to time. In DG:HOMA-IR(p<.035) and leptin(p<.007), EG:FBG(p<.043) and leptin(p<.003), DEG:FBG(p<.014), insulin(p<.005), HOMA-IR(p<.005), leptin(p<.016), and resistin(p<.040) have decreased. In conclusion, combined treatment of eating restriction with aerobic exercise was the most effective way to improvement of weight, blood lipid profiles and metabolic risk factors in obese female college students rather than respectively alone treatment.

• Journal of Life Science
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• v.31 no.5
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• pp.520-526
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• 2021

Microbial protein is one of the sources of protein in the rumen and can also be the source of glutamate production. Glutamic acid is used as fuel in the metabolic reaction in the body and the synthesis of all proteins for muscle and other cell components, and it is essential for proper immune function. Moreover, it is used as a surfactant, buffer, chelating agent, flavor enhancer, and culture medium, as well as in agriculture for such things as growth supplements. Glutamic acid is a substrate in the bioproduction of gamma-aminobutyric acid (GABA). This review provides insights into the role of glutamic acid and glutamic acid-producing microorganisms that contain the glutamate decarboxylase gene. These glutamic acid-producing microorganisms could be used in producing GABA, which has been known to regulate body temperature, increase DM intake and milk production, and improve milk composition. Most of these glutamic acid and GABA-producing microorganisms are lactic acid-producing bacteria (LAB), such as the Lactococcus, Lactobacillus, Enterococcus, and Streptococcus species. Through GABA synthesis, succinate can be produced. With the help of succinate dehydrogenase, propionate, and other metabolites can be produced from succinate. Furthermore, clostridia, such as Clostridium tetanomorphum and anaerobic micrococci, ferment glutamate and form acetate and butyrate during fermentation. Propionate and other metabolites can provide energy through conversion to blood glucose in the liver that is needed for the mammary system to produce lactose and live weight gain. Hence, health status and growth rates in ruminants can be improved through the use of these glutamic acid and/or GABA-producing microorganisms.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.36-46
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• 2022

Purpose: Quercetin is a polyphenolic flavonoid abundant in many fruits and vegetables. It has potential health-beneficial properties, such as antioxidant, anti-obesity, anti-cancer, anti-diabetic and anti-inflammatory effects. The purpose of this study was to investigate whether the lipid metabolism improvement effect of quercetin affected the regulation of AMP-activated protein kinase (AMPK) activity and microRNA (miR)-21 expression in the liver of mice fed a high-cholesterol diet. Methods: Male C57BL/6J mice were fed with normal diet, quercetin-free diet and diets containing 0.05% or 0.1% quercetin for six weeks. Hypercholesterolemia was induced by adding 1% cholesterol and 0.5% cholic acid to all diets. Serum and liver triglyceride (TG), and total cholesterol (TC) concentrations were analyzed using a commercial enzymatic colorimetric kit. AMPK activity was quantified using an AMPK kinase assay kit. The levels of miR-21 and genes involved in lipid metabolism were measured by real-time quantitative polymerase chain reaction. Results: Supplementation of quercetin reduced serum and hepatic TG and TC levels without changing body weight and food intake. Dietary quercetin significantly inhibited the mRNA levels of hepatic sterol-regulatory element binding protein-1c, acetyl-CoA carboxylase 1 and fatty acid synthesis, which are involved in hepatic lipogenesis. Dietary quercetin enhanced AMPK activity and suppressed miR-21 expression, promoting hepatic lipid accumulation. Conclusion: These results suggest that the lipid-lowering effect of quercetin on the serum and liver of mice may be partially mediated by the regulation of lipogenic gene expression, AMPK activity and miR-21 expression in the liver of mice fed a high-cholesterol diet.