• 한국환경보건학회지
• /
• 제29권2호
• /
• pp.80-86
• /
• 2003

To evaluate the effect of cyclohexane(CH) treatment on the serum levels of glutathion S-transferase(GST) activity in liver damaged animals, damaged liver was induced with pretreatment of 50% $CCl_4$ dissolved in olive oil (0.1 m1/100g body weight) intraperitoneally 17 times every other day. To $CCl_4$-treated rats, CH (1.56 g/kg body weight, i.p) was injected once and then the animals were sacrificed at 4 hours after injection of CH. The $CCl_4$-treated animals were identified as severe liver damage on the basis of liver functional findings, 1,e, increased serum levels of alanine aminotransferase(ALT), alkaline phosphate(ALP) and xanthine oxidase(XO) activities. On the other hand, $CCl_4$-treated animals injected with CH once($CCl_4$-pretreated animals) showed more decreased serum levels of ALT and XO, and more increased those of ALP rather than $CCl_4$-treated animals. In case of comparing the GST with ALT activity in liver, both $CCl_4$-treated and pretreated animals showed similar changing pattern of enzyme actvity. Especially $CCl_4$-pretreated animals showed significantly increased serum level of GST actvity compared with the $CCl_4$-treated those, whereas those of ALT showed reversed tendency. In aspects of GST enzyme kinetics, $CCl_4$-pretreated animals showed higher Vmax of liver GST enzyme than $CCl_4$-treated animals. In conclusion, injection of CH to the liver damaged rats led to enhanced liver damage and more increased activity of serum GST which may be chiefly caused by the enzyme induction.

• Journal of Life Science
• /
• 제11권1호
• /
• pp.47-51
• /
• 2001

To investigate the deaging effects of introperitoneally injected Chondroitin Sulfate (CS) on various enzyme activity (AST, ALT, MDA (Malon dialdehyde), SOD (Superoxide dismutase), GPx (Glutathione peroxidases) and histophathology of liver tissue, ovariectomized rats were used. The antioxidative effects of chondroitin sulfate (100 mg/kg and 200 mg/kg body weight) were investigated at the antioxidative enzyme activities of liver homogenate fractions (liver total homogenate, mitochondrial, and microsomal fractions) and sera. In addition, the rat liver was histologically examined. Intraperitoneally injected CS, depend on dosage, indicated a protective effect against ovariectomy-inducted aging. Moreover, inflammation and cirrhosis in liver tissue of CS treated group were significantly decreased. Based on these results, intraperitoneally injected CS is a useful material to delay aging.

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

• Archives of Pharmacal Research
• /
• 제20권2호
• /
• pp.115-121
• /
• 1997

Ile-269 in horse liver alcohol dehydrogenase isoenzyme S(HLADH-S) was mutated to serine by phosphorothioate-based site-directed mutagenesis in order to study the role of the residue in coenzyme binding. The specific activity of the mutant(1269S) enzyme to ethanol was increased 49-fold. All turnover numbers of 1269S enzyme toward 9 primary alcohols were increased. The mutant enzyme showed 3.6, 4.6, 11.6-fold higher catalytic efficiency for $5{\beta}$-androstane-3, 17-dione, $5{\beta}$-cholanic acid-3-one and retinal than wild-type, respectively. The reaction mechanism of 1269S enzyme was ordered bi bi as wild-type's. These results indicate that the hydrophobic interaction of Ile-269 residue with coenzyme plays an important role in dissociation of coenzyme from enzyme-coenzyme complex, which has been known as the rate limiting step of ADH reaction.

• 한국환경성돌연변이발암원학회지
• /
• 제25권3호
• /
• pp.97-103
• /
• 2005

The genotoxic effect of antimalarial drugs amodiaquine (AQ), mefloquine (MQ) and halofantrine (HF) was investigated in.at liver cells using the alkaline comet assay. AQ, MQ and HF at concentrations between $0-1000{\mu}mol/L$ significantly increased DNA strand breaks of rat liver cells dose-dependently. The order of induction of strand breaks was AQ>MQ>HF. The rat liver cells exposed to AQ and HF (200 and 400 ${\mu}mol/L$) and treated with (Fpg) the bacterial DNA repair enzyme that recognizes oxidized purine showed greater DNA damage than those not treated with the enzyme, providing evidence that AQ and HF induced oxidation of purines. Such an effect was not observed when MQ was treated with the enzyme. Treatment of cells with catalase, an enzyme inactivating hydrogen peroxide, decreased significantly the extent of DNA damage induced by AQ, and HF but not the one induced by MQ. Similarly quercetin, an antioxidant flavonoid at $50{\mu}mol/L$ attenuated the extent of the formation of DNA strand breaks by both AQ and HE. Quercetin, however, did not modify the effects of MQ. These results indicate the genotoxicity of AQ, MQ and HF in rat liver cells. In addition, the results suggest that reactive oxygen species may be involved in the formation of DNA lesions induced by AQ and HF and that, free radical scavengers may elicit protective effects against genotoxicity of these antimalarial drugs.

• BMB Reports
• /
• 제29권4호
• /
• pp.335-342
• /
• 1996

Porcine liver cysteinesulfinic acid decarboxylase was purified approximately 460-fold by means of ammonium sulfate fractionation and sequential column chromatographic separation with Sephadex G-100, DEAE-cellulose and hydroxylapatite. The enzyme has a flat pH profile with maximum activity occurring between pH 6.0 and 7.6. Pyridoxal 5'-phosphate must be present in all buffers used for purification procedures in order to stabilize the enzyme. Addition of sulfhydryl reagents such as 2-mercaptoethanol are also necessary to maintain maximum enzyme activity throughout purification. The absorption spectrum shows that cysteinesulfinic acid decarboxylase is a pyridoxal 5' -phosphate-containing protein. The major absorption is at 280 nm with two smaller absorption regions, one at 425 nm which is ascribed to a Schiffs base between pyridoxal phosphate and protein, and another at 325 nm which is thought to be due to the interaction of 2-mercaptoethanol with the Schiffs base. A number of divalent cations tested did not affect enzyme activity with the exception of mercury, copper, and zinc which are inhibitory. The partially purified enzyme has an apparent $K_m$ of 0.94 mM for cysteinesulfinate. Cysteic acid is a competitive inhibitor of the enzyme with a $K_i$ of 1.32 mM. The molecular weight of the enzyme was estimated to be about 79,600 by using Sephadex G-200 column chromatography.

• 한국식품영양과학회지
• /
• 제12권2호
• /
• pp.84-92
• /
• 1983

자동 산화유가 mouse의 간장 효소에 미치는 영향을 구명하기 위하여 autoxidized methyl linoleate의 일정량을 mouse에게 1일 1회 20일 동안 경구 투여하여 간에서의 효소 활성을 조직화학적 및 생화학적 방법으로 검토한 결과는 다음과 같다. 실험군의 간에서의 POV, COV 및 TBA값은 정상군에 비해 크게 증가하여 AOML이 많이 흡수되어 있음을 알 수 있었다. 실험군의 간에서의 phospholipid, triglyceride 및 total cholesterol의 양은 정상군에 비해 증가하였다. 실험군의 간에서의 acid phosphatase, alkaline phosphatase의 활성은 정상군에 비해 증가하였으며, ATPase의 활성은 감소하였다. 실험군의 간에서의 형태학적 변화는 정상군에 비해 핵산의 감소, 지질의 축적 및 간 세포의 손상이 있었다. 이상의 결과로부터 mouse에 경구 투여한 자동 산화 methyl linoleate는 간에서의 효소 활성과 간의 형태학적 변화에 크게 영향을 주고 있음을 알 수 있었다.

• Journal of Nutrition and Health
• /
• 제40권8호
• /
• pp.693-700
• /
• 2007

This study was performed to investigate the effects of genistein, a kind of soy isoflavones, on fatty liver and lipid metabolism in rats fed high fat diet. Twenty four male Sprague-Dawley rats were divided into four groups by dietary fat and genistein contents then raised for six weeks. The rats(n=6/group) were fed normal fat diet(NOR), high fat diet (HF), high fat with 0.1% genistein(HF+0.1%G) or high fat with 0.2% genistein(HF+0.2%G). Hepatic total lipid, triglyceride, total cholesterol and Serum GPT, as a marker for fatty liver, were significantly increased by high fat diet. Also, serum total lipid, triglyceride, total cholesterol, glucose and insulin concentration, hepatic lipogenic enzyme (fatty acid synthase and malic enzyme) activities were significantly increased by high fat diet. However, hepatic total lipid, triglyceride, total cholesterol and Serum GPT were significantly decreased by genistein intake. Also, genistein supplementation decreased serum total lipid, triglyceride, glucose and insulin concentration, hepatic lipogenic enzyme (fatty acid synthase and malic enzyme) activities. There were no differences by genistein level except for serum insulin. These results suggest that fatty liver induced by high fat diet was caused by increased serum lipid profiles and hepatic lipogenesis, whereas, genistein may be useful in inhibiting of fatty liver by reducing serum lipid profiles and hepatic lipogenesis.

• 한국식품영양과학회지
• /
• 제20권6호
• /
• pp.527-537
• /
• 1991

To evaluate an effect of liver xanthine oxidase on the induction of liver damage, carbon tetrachloride (CCl4) was intraperitoneally injected twice at 0.1ml/100g body weight to the rate fed a low (LP)or high protein diet(HP) while the control group fed LP or HP received only olive oil. The changing rate of liver xanthine oxidas activity was compared with that of a free radical generating enzyme, liver aniline hydroxylase and a scavenging enzyme, glutathions S-transferase activity between the rate fed a LP and those fed HP, and the two groups treated with CCl4. Concomitantly, the degree of liver damage which could be considered as the paramete for CCl4 metabolism in case of CCl4-intoxicated animal was observed in the present experimental conditions and the effect of allopurinol, xanthine oxidase inhibitor, on the CCl4-toxicity of rate liver was alos demostrated. On the other hand, the comparative effect of actinomycin D on the liver and serum xanthine oxidase of CCl4-treated rats fed HP with that of those fed LP and the kinetics of purifed liver enzyme from the liver of CCl4-treated rats fed HP was also compared with that of those fed LP to clarify the differences of xanthine oxidase activity between two groups. The increasing rate of liver weigth/body wt, serum levels of ALT and the decreasing rate of hepatic ALT activity and protein contents to each control group were higher in CCl4-treated rats fed HP than those fed LP. Under the animal models as indentified by the present data herein, the liver xanthine oxidase activity was higher in CCl4-treated rats fed HP than those fed LP, and the control group fed HP also showed the much higher activity xanthine oxidase than that fed LP, whereas there were no differences in the activity of hepatic aniline hydroxylase and glutathions S-transferase between the two group treated with CCl4. Although the hepatic aniline hydroxylase activity was somewhat higher in the rats fed HP than those fed LP, the increasing rate of liver xanthine oxidase to the rats fed LP was higher in those fed HP than that of liver aniline hydroxylase. The degree of liver damage identified such as liver weight and serum ALT activity was less in the CCl4-treated rats pretreated with allopurinol. These results suggest that even a system at which xanthine oxidase acts as well as the drug metabolizing enzyme may influence the acelatin of CCl4 metabolism. In addition, the purified liver xanthine oxidase from CCl4-treated rats fed HP showed decreased Km value when compared to its control group. The Km value of liver xanthine oxidase of CCl4-treated rats fed LP showed a similar Km value with its control group. Furthermore, the decreasing rate of liver and serum xanthine oxidase acitivity in CCl4-treated rats pretreated with actinomycin D to the CCl4-treated rats was higher in rats fed HP than in those fed LP. These results suggest that the inductino of xanthine oxidase in CCl4-treated rats fed HP may be greater than in those fed LP.

• KSBB Journal
• /
• 제15권3호
• /
• pp.313-317
• /
• 2000

In this paper enantioselective production of levofloxacin by porcine liver esterase was investigated, To enhance the produc0-tivity various factors which affect the enzyme activity and the enantioselectivity were optimized, In terms of temperature and pH 45$^{\circ}C$ and 4.8 were found to be the best conditions for enzyme reaction. Addition of ofloxacin butyl ester the substrate at the concentration of 5 g/L was desirable to avoid the product inhibition and the activity of porcine liver esterase was maintained up to 72 hours.In addition to enhance the availability of substrate effect of solvent was also examined. It was found that the application of 5% (v/v) of acetone acetonitrile and dimethylsulfoxide did not increase the conversion of substrate and the presence of 5%(v/v) butanol inhibited the enzyme activity significantly.