• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.207-213
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• 1997

The effect of various vegetables commonly consumed by Koreans on the induction of glutathione S-trasferase(GST) activity in mice was assessd. The extract of vegetable dissolved in propylene glycol (5ml/kg body wt.) was administered to ICR female mice 6 to 8 weeks old via gavage during 5 days. The changes of body weight and liver weight of all treated groups were not significantly different compared with control group. Hepatic protein contents of trated groups compared with control group were not significantly different except BHT treated group. The induction of GST activity in liver cytosol of mice was the greatest with broccoli, followed by radish, wild green onion, turnip, and green onion. The induction of GST activity in liver cytosol increased up to 1.5 to 1.8-folds at a dose of 24 g fresh vegetable/mouse. The induction of combination between vegetables was the highest with the combination of broccoli and radish (1.83-fold), followed by that of broccoli and green onion (1.72-fold), and that of broccoli and turnip (1.50-fold).

• Journal of Nutrition and Health
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• v.6 no.1
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• pp.15-29
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• 1973

Albio rats right after weaning, weighing $50{\sim}55g$, were divided into the control, high-carbohydrate-, high-lipid-, and high-protein-fed groups. and were fed for 12 weeks with the respective diets to observe the increase in body weights as well as changes in the chemical constituentes and enzyme activities in the liver tissue, with the following results. (1) There was little difference in the rate of increase in the body weights among the groups, showing normal growth, except the high-protein-fed group which showed decrease in rate of body weight increase from the 7th week after feeding. (2) The liver weight was either increased after 12 weeks of feeding with the high-carbohydrate and high-Lipid diets, or showed no difference with the high-protein diet, as compared to the control weight. (3) The liver cytosol protein content was increased when fed with the high-protein diet, but decreased when fed with the high-carbohydrate and high lipid diets, as compared to the control content. (4) The triglyceride and cholesterol contents in the liver were decreased in the high-protein-fed group, but increased markedly in the high-carbohydrate- and high-lipid-fed groups as compared to the control values. (5) The hepatic glucokinase, G6PD, LDH, and fatty acid synthetase activities were increased in the high-carbohydrate and high-lipid-fed groups, and GOT and CPT activities were increased in the high-protein-fed group. From the above results. it was known that the high-carbohydrate and high-lipid diets stimulated the hepatic lipid metabolism, giving rise to lipogenesis, but the high- protein diet could prevent the lipogeuesis leading to the body weight increase.

• BMB Reports
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• v.56 no.7
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• pp.385-391
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• 2023

Aspartate-glutamate carrier 2 (AGC2, citrin) is a mitochondrial carrier expressed in the liver that transports aspartate from mitochondria into the cytosol in exchange for glutamate. The AGC2 is the main component of the malate-aspartate shuttle (MAS) that ensures indirect transport of NADH produced in the cytosol during glycolysis, lactate oxidation to pyruvate, and ethanol oxidation to acetaldehyde into mitochondria. Through MAS, AGC2 is necessary to maintain intracellular redox balance, mitochondrial respiration, and ATP synthesis. Through elevated cytosolic Ca²⁺ level, the AGC2 is stimulated by catecholamines and glucagon during starvation, exercise, and muscle wasting disorders. In these conditions, AGC2 increases aspartate input to the urea cycle, where aspartate is a source of one of two nitrogen atoms in the urea molecule (the other is ammonia), and a substrate for the synthesis of fumarate that is gradually converted to oxaloacetate, the starting substrate for gluconeogenesis. Furthermore, aspartate is a substrate for the synthesis of asparagine, nucleotides, and proteins. It is concluded that AGC2 plays a fundamental role in the compartmentalization of aspartate and glutamate metabolism and linkage of the reactions of MAS, glycolysis, gluconeogenesis, amino acid catabolism, urea cycle, protein synthesis, and cell proliferation. Targeting of AGC genes may represent a new therapeutic strategy to fight cancer.

• BMB Reports
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• v.30 no.3
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• pp.222-228
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• 1997

Protein phosphatase 2C (PP2C) is one of the four major serine/threonine phosphatases which is dependent on $Mg^{2+}$ for its activity. PP2C was purified from rat liver cytosol and its characteristics were investigated. The substrate employed for routine assay was $[^{32}P]casein$ phosphorylated by PKA. The purification process involved DEAE chromatography, ammonium sulfate fractionation, phenyl sepharose chromatography, sephacryl 5-200 gel filtration, and histone agarose chromatography. The SDS-PAGE of PP2C showed one major single protein band at a position corresponding to a molecular mass of 43 kd and the purification fold was 637. The enzyme showed a pH optimum of 8 and $K_M$ value was $1.9\;{\mu}M$. However, when the substrate was changed to $[^{32}P]histone$, the pH optimum was shifted to 7 and $K_M$ value was $2.3\;{\mu}M.\;Mg^{2+}$ was essential to the enzyme activity and okadaic acid did not exert any inhibitory effect on the enzyme. To examine residue in the active site of PP2C effects of some protein-modifying reagents were tested.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.261-261
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• 1994

Bovine milk xanthine oxidase (E.C.1.1.3.22, XO) purchased from Sigma Chemical Co. had the three protein fragments below 150 kDa on 7.5％ SDS-PAGE, which did not show enzyme activity. To remove these fragments, the enzyme preparation was further purified through Sephadex G-200 column chromatography. Two peaks exhibiting enzymatic activity were separated very closely to the void volume, which were revealed as two different enzyme forms, dimeric and monomeric, confirmed by activity staining on native PAGE. Anti sera-against each of the two enzyme forms were raised by subcutaneous injection at multiple sites on the back of rabbits during 4 weeks. On the immunodiffusion test, it was found that both of the antisera of the two forms could react with each other, which implied that their epitopes were identical In the Western blot analysis of mouse liver cytosol fraction, it was found that rabbit anti-XO antibody bound well with the protein band of monomeric mouse liver XO of about 150kDa. Based on this result, mouse liver cDNA 1 ibrary was screened by in situ hybridizat ion wi th rabbi t anti -XO antibody as probe. Through the immunological screening, recombinant phages giving positive signal by the production of XO were selected and further purified. To validate these clones, purified phages were lysogenized in E. coli Y1089 and their lysates were analysed for enzyme activity and immunoreactivity, It was verified that lysates of the purified recombinant phage lysogens exhibited the enzymatic activity as well as bound wi th XO antibody, when induced by IPTG. The above results assert that selected recombinant phage carries mouse liver XO gene.

• Journal of Life Science
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• v.32 no.9
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• pp.678-689
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• 2022

HK shiitake mushroom mycelium (HKSMM), containing 14% β-glucan, is a health functional food ingredient approved individually for liver health by the Ministry of Food and Drug Safety. The immune-enhancing efficacy of a 50% aqueous ethanol extract of HKSMM (designated HKSMM50) was studied in Jurkat cells activated with concanavalin A (ConA). Active hexose correlated compound (AHCC) was used as a positive control. ConA-activated Jurkat cells were treated with HKSMM50 (0, 25, 50, 100 ㎍ g/ml) or AHCC (100 ㎍ g/ml), and cultured for 3 and 6 hours. The nuclear factor of activated T cells (NFAT) protein content in the cytosol and the nucleus was measured by Western blotting. Interleukin-2 (IL-2), interferon-gamma (IFN-γ), and cyclooxygenase-2 (COX-2) were determined using enzyme-linked immunosorbent assay (ELISA) kits. HKSMM50 lowered NFAT content in the cytosol, but elevated NFAT content in the nucleus. The IL-2 and IFN-γ productions were elevated. Meanwhile, both COX-2 activity and apoptosis were suppressed. The efficacy of the AHCC treatment showed similar to those of HKSMM50 treatments. These results indicate that the HKSMM50 exhibited immune-enhancing effects in ConA-treated Jurkat cells by activation of NFAT protein, and suggest that HKSMM could be used as a health functional food ingredient to improve immune functions in humans.

• Journal of Aquaculture
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• v.6 no.2
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• pp.107-123
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• 1993

To define the effects of various levels $(0\~1.5\%)$ of dietary n-3HUFA on the physiological changes in the Korean rockfish, variations in blood variables and hepatocytes were studied. Biochemical serum analyses, lactate dehydrogenase (LDH) activity of the liver cytosol and ATPase activity of the liver microsomal membrane were also studied. The haematological values (red blood cell, hemoglobin, hematocrit, MCHC, MCV and MCH) were not significantly different in the experimental groups $(P\geq0.05)$. The total protein and glucose levels in the serum were affected by dietary n-3HUFA levels. These levels in groups fed n-3HUFA insufficient diets were significantly lower than those of n-3HUFA sufficient groups (P<0.05). Serum levels of total cholesterol, free cholesterol, glutamic pyruvic transaminase (GPT) and glutamic oxaloacetatic transaminase (GOT) showed significantly higher values in the fish fed n-3HUFA deficient diets (P<0.05). The LDH in the serum was dropped with increasing dietary n-3HUFA levels, but the LDH activity of the liver cytosol was elevated. Histologically, the hepatic cell in the fish fed n-3HUFA free diet was abnormal and showed a necrotic condition. $Ca^{2+}-ATPase$ activities of the liver microsomal membrane were significantly lower in the fish fed n-3HUFA deficient diets than in those fed n-3HUFA sufficient diets (p<0.005). These results suggested that the liver cell membrane was affected by dietary fatty acid compositions and cell membrane of the fish fed n-3HUFA insufficient diets showed abnormalities.

• Biomedical Science Letters
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• v.12 no.3
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• pp.249-254
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• 2006

It has been reported that liver is a very important organ to xenotransplantation. Pig is known to be a most suitable species in transplantation of human organs. However, the physiological function of pig hepatocytes is not clear elucidated. Epidermal growth factor (EGF) is known to be a mitogen in various cell systems. Thus, we examined the effect of EGF on cell proliferation and its related signal cascades in primary cultured pig hepatocytes. EGF stimulates cell proliferation in a dose (>1ng/ml) dependent manner. EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by AG 1478 ($10^{-6}M$, an EGF receptor antagonist) genistein and herbymycin A (tyrosine kinase inhibitors, $10^{-6}M$), suggesting the role of activation and tyrosine phosphorylation of EGF receptor. In addition, EGF-induced increase of $[^3H]-thymidine$ incorporation was prevented by neomycin $(10^{-4}M)$, U73122 $(10^{-5}M)$ (phospholipase C [PLC] inhibitors), staurosporine ($(10^{-8}M)$, or bisindolylmaleimide I $(10^{-6}M)$ (protein kinase C [PKC] inhibitors), suggesting the role of PLC and PKC. Moreover, EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by PD 98059 (a p44/42 mitogen activated protein kinase [MAPK] inhibitor), SB 203580 (a p38 MAPK inhibitor), and SP 600125 (a JNK inhibitor). EGF increased the translocation of PKC from cytosol to membrane fraction and activated p42/44 MAPK, p38 MAPK and JNK. In conclusion, EGF stimulates cell proliferation via PKC and MAPK in cultured pig hepatocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.725-730
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• 1994

This study was conducted to investigate the effect of dietary zinc (Zn) and/or cadmium (Cd) on hepatic microsomal and cytosol enzyme activities. Male Spraque-Dawley rats (110$\pm$10g ) received zinc (0, 30 and 300 ppm/) and Cd-treated groups were administered oral intubation with Cd chloride (5.0mg/kg of body weight 0 at the same time once a week. The effect of Cd on the activity of hepatic cytochromep-450 , xanthine oxidase(X. O) and superoxide dismutase (SOd) was studied in rats. Cd oral intubation resulted in a decrease in cytochrome P-450 content and SOD activity whereas a significant increase in the X.O. activity was observed was observed . Intake of excessive Zn led to an increased activity of microsomal alcohol dehydrogenase (ADH) , whereas Zn deficiency group led to a decreased group. The mechanism by which Zn induces the decreasing of Cd toxicity in rats, seems to rely on the protection of the enzyme systems P-450, ADH, aldehyde dehydrogenase (ALDH) and X.O. in the liver, possibly by forming non-toxic Cd metallothionein. These results indicate that Zn and Cd regulation might occur via inhibitory protein component of the $H_2O$$_2$ -generator system.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.29-36
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• 2009

To compare antioxidative and antiaging effects between yellow soybean (YS) and Chungkukjang (CK) in vivo system, male Sprague-Dawley rats (n=24) were fed the diets containing YS and CK for 8 weeks, respectively. The YS and CK groups showed the preventive effects on lipid and protein oxidations in liver and plasma. Hepatic SOD and GSH-peroxidase activities were significantly inhibited in CK group. Superoxide anion radicals in cytosol significantly lowered in YS and CK groups compared with control group. In addition, dietary YS and CK effectively inhibited formation of the lipofuscin, the indicator of aging in heart and eye, especially the CK group had a stronger preventive activity in eye. The results of this study showed that YS and CK diet effectively suppressed the superoxide anion radical formation and tissue oxidation.