• 동의생리병리학회지
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• 제20권1호
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• pp.25-30
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• 2006

This Study was designed to investigate the effects of Patholobi Caulis on the change of regional cerebral blood flow (rCBF) and blood Pressure (MABP) in normal and Cerebral ischemic rats. And, this Study was designed to investigate the inhibition of lactate dehydrogenase (LDH) activity in neuronal cells. The results were as follows : In normal rats, Patholobi Caulis significantly increased rCBF in a dose-dependent manner, and MABP was somewhat increased. In ischemia rats, rCBF was significantly and stably increased by Patholobi Caulis (10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. Patholobi Caulis significantly inhibited LDH activity in neuronal cells. It was suggested that Patholobi Caulis had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• 대한환경공학회지
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• 제29권3호
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• pp.283-288
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• 2007

연속회분식반응조(SBR) 공정에서 슬러지 체류시간(SRT)에 따른 중금속의 독성도 변화를 측정하였다. 중금속은 구리(Cu), 카드뮴(Cd) 및 아연(Zn)을 사용하였고, SRT는 $2\sim30$일로 변화시켰으며, 독성도는 INT-dehydrogenase 활성도의 변화로 측정하였다. 중금속의 농도가 증가함에 따라 독성도가 증가하였으며, Cu가 Zn 및 Cd 보다 독성도가 높았다. SRT를 변화시켰을 때 $IC_{50}$ 값이 Cu의 경우 $0.37\sim1.96$ mg/L의 범위를 나타내었으며, Cd의 경우는 $15.4\sim16.9$ mg/L를 나타내었다. 또한 Zn의 경우는 $9.70\sim23.4$ mg/L의 범위를 나타내었다. Cu와 Zn의 경우, SRT가 증가함에 따라 독성이 감소하였으며, 이는 긴 SRT에서 세포외 중합체의 농도가 증가하기 때문인 것으로 판단된다. 따라서 중금속을 포함한 산업폐수를 처리하는 SBR 공정에서 SRT를 길게 운영하는 것이 바람직할 것으로 판단된다.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.265-269
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• 2003

Gamma irradiation treatment was performed at the early and mid-fermentation stages of Kimchi preparation. Changes in fermentative microorganisms and lactate dehydrogenase activity during the fermentation periods were investigated to determine proper irradiation point for extending the shelf life of Kimchi. Initial levels of acid producing bacteria and yeast in Kimchi were 10$^4$ CFU g$^{-1}$ and 10$^1$ CFU g$^{-1}$ , and reached up to 10$^{9}$ CFU g$^{-1}$ after 15 days and 10$^{7}$ CFU g$^{-1}$ after fermentation for 30 days at 1$0^{\circ}C$, respectively. The radiation resistance of acid producing bacteria in the earlier stage (D$_{10}$ value was 0.87 kGy) was higher than at the midfermentation stage (after 10 days at 1$0^{\circ}C$, D$_{10}$ value was 0.69 kGy). Microbial growth and lactate dehydrogenase activity were inhibited significantly by gamma irradiation at the early fermentation stage of Kimchi and acidification was effectively delayed during the subsequent storage period. Although the growth of fermentative microorganisms was inhibited by gamma irradiation at the mid-fermentation stage of Kimchi, lactate dehydrogenase activity was maintained and acidification continued during the storage period.

• 한국환경농학회지
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• 제36권4호
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• pp.223-229
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• 2017

BACKGROUND: Tillage systems and fertilization play an important role in crop growth and soil improvement. This study was conducted to determine the effects of tillage and fertilization on the microbial biomass C and dehydrogenase activity of soils in a field under cultivation of soybean. METHODS AND RESULTS: An experimental plot, located in the temperate climate zone, was composed of two main sectors that were no-tillage (NT) and conventional tillage (CT), and they were subdivided into four plots, respectively, in accordance with types of fertilizers (non fertilizer, chemical fertilizer, hairy vetch, and liquid pig manure). Microbial biomass C and dehydrogenase activity were evaluated from May to July in 2016. The microbial biomass C and dehydrogenase activity of NT soils were significantly higher than those of CT in all fertilizer treatments, and they were further increased in hairy vetch treatment than the other fertilizer treatments in both NT and CT. The dehydrogenase activity was closely related to microbial biomass C. CONCLUSION: It is concluded that application of green manure combined with no-tillage can provide viable management practices for enhancing microbial properties of soil.

• Toxicological Research
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• 제35권1호
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• pp.13-24
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• 2019

Numerous ethnomedicinal uses have been attributed to different parts of Annona senegalensis (ASE), including its uses as food and food additives. The present study investigated toxicological and antioxidant effects of 28 days administration of ethanol extracts of ASE stem bark to Wistar strain albino rats. Acute toxicity test was done to determine lethal dose in Wistar rats while sub-acute toxicity test was conducted on rats divided into four groups (A - control, B - 50 mg/kg, C - 100 mg/kg, D - 150 mg/kg, respectively and treated for 28 days. Oxidative stress markers in liver and kidney as well as hepatic succinate dehydrogenase activity in the mitochondrial and post mitochondrial fractions (PMF) were evaluated. The $LD_{50}$ value of ASE was > 2,000 mg/kg. White blood cell counts gradually increased, but red blood cell counts and haematocrits level decreased significantly (p < 0.05) by about 50%. Liver enzymes in the serum and mitochondrial succinate dehydrogenase activity increased significantly (p < 0.05). Superoxide dismutase and catalase activities also increased in liver mitochondria and PMF while malondialdehyde (MDA) and reduced glutathione levels increased only in the PMF. Furthermore, only MDA levels increased significantly in the kidney after 28 days extract administration. Histopathological examination showed hepatic necrosis and no obvious signs of nephrotoxicity. Anona senegalensis is relatively safe, but prolonged ingestion could induce oxidative stress and impair ATP synthesis through the modulation of the activity of mitochondrial succinate dehydrogenase.

• Journal of Nutrition and Health
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• 제27권9호
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• pp.892-900
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• 1994

A variety of important roles for branched-chain amino acids in metabolic regulation has been suggested. Branched-chain $\alpha$-keto acid dehydrogenase(BCKAD) complex is a rate limiting enzyme in branched-chain amino acid metabolism. The purpose of this study was to examine the effects of exercise on the activity and activity state of branched-chain $\alpha$-keto acid dehydrogenase in rat hert and liver thssues. Forty-eight Sprague-Dawley rats were assigned into three experimental groups : sedentary control, exercised, or exercised-rested. Submaximal exercise(running) for two hours significantly increased basal activity without a change in total activity in both tissues, with a concomitiant increase in activity state of the enzyme complex. At 10 min post-exercise, heart enzyme activity significantly decreased, though not to the control level, while liver enzyme activity remained unchanged. These data suggested that the exercise-induced increase in branched-chain $\alpha$-keto acid decarboxylation in rat tissues may not be the result of enzyme synthesis, but rather is due to increased activity of the BCKAD.

• 환경생물
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• 제20권2호
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• pp.173-179
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• 2002

N-nitrosoethylurea(NEU)에 의한 지질 과산화물의 함량 변화와 알데히드 대사효소 및 항산화효소의 활성변화를 쥐 간세포에서 측정하였다. 알데히드 대사효소로는 alcohol dehydrogenase와 aldehyde dehydrogenase가 사용되었고 항산화효소로는 glutathione transferase, superoxide dismutase, glutathione reductase와 catalase가 사용되었다. 쥐 간세포에 다양한 농도의 NEU를 처리한 후 지질 과산화물의 함량변화를 측정하였다. 그 결과 6.25mM NEU에 의하여 지질 과산화물의 함량이 최대 2.5배 증가하였다. Alcohol dehydrogenase의 활성은 NEU처리에 의하여 대조군보다 최대 2.3배 증가하였고 aldehyde dehydrogenase의 활성은 약 2배 증가하였다. 전암성 병변의 지표로 이용되는 glutathione transferase와 catalase의 경우 NEU처리에 의한 활성증가가 미미하였다. 그러나 superoxide dismutase의 활성은 최대 1.5배 증가하였고, glutathione reductase의 활성은 약 3배 증가하였다. 그러므로 superoxide dismutase와 g1utathione reductase의 활성증가가 NEU의 독성에 대한 세포내 항산화 방어과정에서 중요한 역할을 할 것으로 추측된다

• Nutrition Research and Practice
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• 제2권2호
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• pp.80-84
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• 2008

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ${\sim}5$ fold and glucose 6-phosphate dehydrogenase activities were decreased by ${\sim}25%$ compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased siguificantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to fimction in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.

• 한국응용곤충학회지
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• 제34권3호
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• pp.181-190
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• 1995

암컷 Aedes aegypti의 난성숙과장에서 새로 나타나는 malate dehydrogenase(L-malate, $NAD^+$ oxidoreductase, EC 1.11.37, MDH)를 DEAE-Sepharose, Sulphonyl-Sepharose, Cibacron 3FGA affinity chromatography를 이용하여 분리정제하여 그 특성을 조사하였다. 분자량은 70,000 dalton정도의 dimer 형태로 되어 있으며 최적 pH는 malate-oxaloacetate반응에서는 pH 9.0~9.2, oxaloacetate-malate 반응에서는 pH 9.8~10.2이었다. 정재된 MDH는 mitochondria에 위치하고 있으며 기질로서 malate에 대한 Km값의 경우 $1.29 \times 10^{-4}$ M, oxaloacetate에 대한 Km 값은 $6.58\times 10^{-4}$M, NAD에 대한 Km값은 $0.76\times 10^{-3}$ M이며 NADH에 대한 Km 값은 $3.8\times 10^{-3}$ M 을 보이고 있으며 각각의 기질에 의한 저해현상을 보이고 있었다. 기질에 대한 Km값을 부분적으로 분리한 DEAE-sepharose에 흡착된 원형질 MDH와 비교한 결과 malate에 대한 Km 이 $8.92\times 10^{-3}$으로 상당한 차이를 보이고 있었다. 또한 정제된 MDH는 cltrate, $\alpha$-ketoglutarate, ATP 등의 대사산물에 의하여 저해작용을 받았다. ATP 및 citrate에 의한 MDH 활성도 저해는 oxaloacetate-malate반응에서 보다는 malate-oxaloacetate 반응에서 덜 일어났다. Oxaloacetate-malate 반응의 경우 ATP에 의하여저해작용이 완전히 일어났으며 malate-oxaloacetate반응에서는 cltrate에 의하여 저해작용이 일어나지 않았다. 흡혈 후 생성되는 MDH는 난소에서 합성되며 흡혈 수 난소에서 18시간 때부터 활성도가 나타나 48시간 이후 최고 활성도가 유지되는데 TCA회로의 isocitrate dehydrogenase 의 경우 난소내에서의 활성도 변화가 MDH의 변화 양상과 같았다.

• Journal of Ginseng Research
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• 제21권3호
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• pp.174-186
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• 1997

In this study, rat hepatocytes known to have active carbohydrate metabolism were obtained by using the liver perfusion technique to examine the hypoglycemic action of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only, The specific activities of some regulatory enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and glucose 6-phosphatase, in main pathways which were directly related to the glucose metabolism were compared between these two kinds of hepatocytes cultured in two different media. The effects of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] under the concentration of $10^3$~$10^6$% on these enzymes In hepatocytes were also investigated, when they were added to these two media. The results were as follows. The specific activity of enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one, however, their decreased activity was recovered after the addition of ginseng components at all range of concentrations. The increased specific activity of these on - zymes was shown by the addition of ginseng components to the control group. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their Increased activity was decreased after the addition of ginseng components at all range of concentrations. The same results were obtained after the addition of ginseng components to the control group. These results suggest that the red ginseng saponin components might better diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or Indirectly though more detailed studies were needed.