• Title/Summary/Keyword: Demethylase

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Effect of Vitamin C and E on Hepatic Biliary and Microsomal Function in Hepatic Ischemia/reperfusion

  • Kim, Soon-Ae;Seo, Min-Young;Cho, Tai-Soon;Lee, Sun-Mee
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.205-205
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    • 1996
  • 본 실험은 간장허혈 및 재관류시 야기되는 간장 손상에 대해 vitamin C와 E 각각의 효과와 이들의 병용효과를 알아보고자 하였다. 실험군은 흰쥐에 vitamin E(25mg/kg)를 실험전 3일간 투여한 군, vitamin C(100mg/kg)를 실험 5분전 경정맥주사한 군 및 vitamin C와 E의 병용 투여군등의 3군으로 하여 각각에 허혈을 유발시킨 후 (60분) 재관류 1시간, 5시간에 간세포 손상정도(AI.T, AST, liver wet-weight to dry-weight ratio), 지질과산화(MDA), 담즙분비변동(bile flow, bilirubin, cholate output) 및 약물대사효소계의 변동(cytochrome P$_{450}$, aminopyrine-N-demethylase, aniline p-hydroxylase activity) 등을 관찰하였다. 실험결과로는 허혈 및 재관류로 인한 ALT, AST MDA는 재관류 5시간에 최고치를 이루었으며 이는 vitamin C와 vitamin E의 각각 투여로 억제되었고, 특히 vitamin C와 E의 병용투여로 더욱 현저하게 억제되었다. 간세포 부종의 지표인 liver wet-weight to dry-weight ratio도 vitamin C와 E의 병용투어로 유의성있게 억제되었다. 담즙분비량 및 담즙산량은 vitamin C 투여와 vitamin C와 E 병용투여로 허혈 및 재관류로 감소된 양을 증가시켰고, 특히 vitamin C와 E의 병용투여는 담즙분비량에 있어 현저한 상승을 나타내었다. 허혈 및 재관류로 인한 cytochrome P$_{450}$양의 감소와 aminopyrine N-demethylase 활성의 억제는 vitamin C 투여와 vitamin C와 E의 병용투여에 의해 유의성 있게 증가하였다. 이상의 결과로 보아 vitamin C와 vitamin E는 각각 허혈 및 재관류로 인한 간장손상을 완화시켰으며 특히 vitamin C와 E의 병용투여는 상승적으로 적용하여 간세포손상을 더욱 억제시킴을 알 수 있었다.

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Effect of Allopurinol Pretreatment on the Liver Damage in $CCl_4$-treated Rat (흰쥐에 있어서 사염화탄소에 의한 간손상에 allopurinol의 영향)

  • 배지혜;윤종국;이상일
    • Toxicological Research
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    • v.11 no.2
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    • pp.247-252
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    • 1995
  • To evaluate the effect of xanthine oxidase on liver injury by $CCl_4$, liver damage was induced both in allopurinol pretreated rats (500 mg/kg. ip) and control group by twice intraperitoneal injection of $CCl_4$ (0.1 ml/100 g body wt. 50% in olive oil) at interval of one day. Increases in the levels of serum alanine aminotransferase and liver weight/body weight (%) by $CCl_4$ were significantly smaller inallopurinol pretreated rats than in control whereas the hepatic microsomal glucose-6-pholphatase activities were significantly higher in allopurinol pretreated rats than control group by $CCl_4$ treatment. These results indicates that allopurinol pretreatment may reduce the liver damage in $CCl_4$ intoxicated rats. In rats either with $CCl_4$or not, hepatic type O xanthine oxidase activities were significantly reduced by allopurinol pretreatment and the increasing rate of these enzymes to each control was remarkably lower in allopurinol pretreated rats than control. Liver cytosolic protein contents and aniline hydroxylase, aminopyrine demethylase activities were higher in allopurinol pretreated rats than coirol rats when animals were treated with $CCl_4$. On the other hand, neither allopurinol pretreated nor $CCl_4$ treatment caused any significant changes in hepatic superoxide dismutase and catalase activities. Hepatic glutathione contents were higher in $CCl_4$-treated rats than control, but no significant changes were found in both between the allopurinol treated rats and $CCl_4$-treated rats pretreated with allopurinol, and glutathione and glutathione S-transferase activities were significantly reduced in $CCl_4$-treated rats than control whereas these enzyme activities showed on significant change in both between allopurinel treated and $CCl_4$-treated rats pretreated with allopurinol. It is concluded that xanthine oxidase reaction system augment $CCl_4$ induced liver injury via even oxygen free radical system.

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Increase of the D-chiro-inositol and D-Pinitol Contents by Abiotic Stress in the Buckwheat Seedlings (쓴메밀 유식물에서 비 생물학적 스트레스에 의한 D-chiro-inositol과 D-pinitol의 함량 증가)

  • Ahn, Chul-Hyun;Park, Phun-Bum
    • Journal of Life Science
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    • v.19 no.10
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    • pp.1456-1462
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    • 2009
  • D-chiro-Inositol, which is the isomer of myo-inositol, is a well known drug for the treatment of type II diabetes. The methylated form of D-chiro-inositol, D-pinitol and D-chiro-inositol are synthesized when the plants are exposed to the abiotic stresses such as drought, salinity and low temperature as osmoprotectants. In soybean, myo-inositol is converted to ononitol by O-methyltransferase, and ononitol is converted to D-pinitol by ononitol epimerase and finally converted to D-chiro-inositol by demethylase. However there have been some reports that in buckwheat, myo-inositol can be converted to D-chiro-inositol directly. This study was conducted to determine the changes of soluble cyclitols in buckwheat seedlings after exposure to salt and drought stresses by GC-FID. The results indicated that myo-inositol may be the precursor of D-chiro-inositol biosynthesis.

Effect of membrane lipid peroxidation on rat liver microsomal enzyme activity (막지질 과산화와 간세포내 마이크로솜 및 리덕타제 기능과의 상관성에 관한 연구)

  • Park, Sang-Youel;Cho, Jong-Hoo
    • Korean Journal of Veterinary Research
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    • v.44 no.2
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    • pp.185-193
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    • 2004
  • The effects of membrane lipid peroxidation and retinyl palmitate on rat liver microsomal functions were investigated in vitro. Rat liver homogenates exposed to oxygen tension for 0, 3, 6, 9 or12 hours and lipid peroxidation levels were evaluated by the measurements of fluorescence intensity, malondialdehyde (MDA) and retinyl palmitate. The fluorescence intensity of homogenates and microsomes were elevated and retinyl palmitate concentrations were decreased. But the concentration of MDA was not affected to exposure time. Therefore, fluorescence intensity and retinyl palmitate concentration were used to analyze the correlation between lipid peroxidation and microsomal functions. To investigate the liver microsomal functions, the microsome was isolated from rat liver homogenates exposed to oxygen. The concentration of cytochrome P450 and the activity of NADPH-cytochrome P450 reductase in liver microsomes were gradually decreased with increasing the exposure time. The correlation between fluorescence intensity of microsomes showed a very high inverse correlation of -0.97 and -0.93, respectively. The decrease of cytochrome P450 concentration was due to the regeneration of cytochrome P450 to cytochrome P420. Also, the activities of cytochrome P450-dependent aminopyrine demethylase and benzpyrene hydroxylase of liver microsomes were gradually decreased with increasing the exposure time. The correlation with fluorescence intensity of microsome showed a high inverse correlation of -0.97 and -0.91, respectively. The retinyl palmitate concentrations of rat liver homogenates were decreased with increasing the exposure time. The decrease of retinyl palmitate concentration was followed by a low concentration of cytochrome P450 and activity of NADPH-cytochrome P450 reductase. The correlation indicated high direct correlation of 0.92 and 0.93, respectively. The decrease of retinyl palmitate concentration was also accompanied by the reduction of aminopyrine demethylase and benzpyrene hydroxylase activities. The correlation was analyzed a high direct correlation of 0.90 and 0.85, respectively. In conclusion, these studies have shown that the membrane lipid peroxidation of rat liver microsome proportionally decreased microsomal enzyme activities in vitro experiments.

GSK-J4-Mediated Transcriptomic Alterations in Differentiating Embryoid Bodies

  • Mandal, Chanchal;Kim, Sun Hwa;Kang, Sung Chul;Chai, Jin Choul;Lee, Young Seek;Jung, Kyoung Hwa;Chai, Young Gyu
    • Molecules and Cells
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    • v.40 no.10
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    • pp.737-751
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    • 2017
  • Histone-modifying enzymes are key players in the field of cellular differentiation. Here, we used GSK-J4 to profile important target genes that are responsible for neural differentiation. Embryoid bodies were treated with retinoic acid ($10{\mu}M$) to induce neural differentiation in the presence or absence of GSK-J4. To profile GSKJ4-target genes, we performed RNA sequencing for both normal and demethylase-inhibited cells. A total of 47 and 58 genes were up- and down-regulated, respectively, after GSK-J4 exposure at a log2-fold-change cut-off value of 1.2 (p-value < 0.05). Functional annotations of all of the differentially expressed genes revealed that a significant number of genes were associated with the suppression of cellular proliferation, cell cycle progression and induction of cell death. We also identified an enrichment of potent motifs in selected genes that were differentially expressed. Additionally, we listed upstream transcriptional regulators of all of the differentially expressed genes. Our data indicate that GSK-J4 affects cellular biology by inhibiting cellular proliferation through cell cycle suppression and induction of cell death. These findings will expand the current understanding of the biology of histone-modifying enzymes, thereby promoting further investigations to elucidate the underlying mechanisms.

Biotransformation of Theophylline in Cirrhotic Rats Induced by Biliary Obstruction

  • Park, Eun-Jeon;Ko, Geon-Il;Kim, Jae-Baek;Sohn, Dong-Hwan
    • Archives of Pharmacal Research
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    • v.22 no.1
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    • pp.60-67
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    • 1999
  • The object of this work was to study the pharmacokinetic differences and the cause of these differences in cirrhotic rats induced by biliary obstruction when aminophylline (8 mg/kg as theophylline, i.v.) was administered. The concentrations of theophylline and its major metabolite (1,3-dimethyluric acid) in plasma were determined by HPLC. In addition, formation of 1,3-dimethyluric acid from theophylline in microsomes and the changes in the activity of drug metabolizing enzymes, which are suggested to be involved in theophylline metabolism, were determined. In cirrhotic rats, the systemic clearance of theophylline was reduced to 30% of the control value while AUC (area under the palsma concentration-tie curve) and (t1/2)$\beta$ were increased 1.3 fold and3.5 fold, respectively. The formation of 1,3-dimethyluric acid was decreased to 30% of the control value in microsomes of cirrhotic rat liver. In cirrhotic rat liver, activities of aniline hydroxylase (CYP2E1 related), erythromycin-N-demethylase (CYP3A related), and methoxyresorufin-O-demethylase (CYP1A2 related), which were reported to be related with theophyline metabolism, were decreased to 67%, 53%, and 76% that of normal rat liver, respectively. From the results, it can be concluded that in cirrhotic rats induced by biliary obstruction, the total body clearance of theophylline is markedly reduced and it may be due to decreased activity of drug metabolizing enzymes in liver.

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Effect of GE-132 on the Hepatic Bromobenzene Metabolizing Enzyme System in Rats (유기게르마늄(GE-132)이 Bromobenzene의 대사계에 미치는 영향)

  • 김석환;조태현;최종원
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.6
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    • pp.702-708
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    • 1993
  • The study was attempted to elucidate the mechanism of GE-132(100mg/kg, p.o. for 6 weeks) on the metabolism of bromobenzene (460mg/kg, i.p. bid, for 2 days), which has potent carcinogenicity, mutagenicity and hepatotoxicity. It showed that activities of cytochrome p-450, aminopyrine demethylase and aniline hydroxylase, which have epoxide generating property, were not changed by GE-132 treatment. On the other hand, epoxide hydrolase was not changed but that glutathione S-transferase was significantly increased by GE-132 treatment. And also ${\gamma}-glutamylcysteine$ synthetase was not changed following the GE-132 treatment, but the activity of glutathione reductase was significantly increased. The level of hepatic glutathione which was decreased by bromobenzene recovered markedly by GE-132 pretreatment. It is concluded that the mechanism for the observed effect of GE-132 on bromobenzene metabolism is due to the induction of glutathione S-transferase.

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Sensitivity of the Pyrenophora teres Population in Algeria to Quinone outside Inhibitors, Succinate Dehydrogenase Inhibitors and Demethylation Inhibitors

  • Lammari, Hamama-Imene;Rehfus, Alexandra;Stammler, Gerd;Benslimane, Hamida
    • The Plant Pathology Journal
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    • v.36 no.3
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    • pp.218-230
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    • 2020
  • Net blotch of barley caused by Pyrenophora teres (Died.) Drechsler, is one of the most destructive diseases on barley in Algeria. It occurs in two forms: P. teres f. teres and P. teres f. maculata. A total of 212 isolates, obtained from 58 fields sampled in several barley growing areas, were assessed for fungicide sensitivity by target gene analysis. F129L and G137R mitochondrial cytochrome b substitution associated with quinone outside inhibitors (QoIs) resistance, and succinate dehydrogenase inhibitors (SDHIs) related mutations (B-H277, C-N75S, C-G79R, C-H134R, and C-S135R), were analyzed by pyrosequencing. In vitro sensitivity of 45 isolates, towards six fungicides belonging to three chemical groups (QoI, demethylase inhibitor, and SDHI) was tested by microtiter technique. Additionally, sensitivity towards three fungicides (azoxystrobin, fluxapyroxad, and epoxiconazole) was assessed in planta under glasshouse conditions. All tested isolates were QoI-sensitive and SDHI-sensitive, no mutation that confers resistance was identified. EC50 values showed that pyraclostrobin and azoxystrobin are the most efficient fungicides in vitro, whereas fluxapyroxad displayed the best disease inhibition in planta (81% inhibition at 1/9 of the full dose). The EC50 values recorded for each form of net blotch showed no significant difference in efficiency of QoI treatments and propiconazole on each form. However, in the case of fluxapyroxad, epoxiconazole and tebuconazole treatments, analysis showed significant differences in their efficiency. To our knowledge, this study is the first investigation related to mutations associated to QoI and SDHI fungicide resistance in Algerian P. teres population, as well as it is the first evaluation of the sensitivity of P. teres population towards these six fungicides.

Isolation of Hepatic Drug Metabolism Inhibitors from the Seeds of Myristica fragrans

  • Shin, Kuk-Hyun;Kim, Ok-Nam;Woo, Won-Sick
    • Archives of Pharmacal Research
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    • v.11 no.3
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    • pp.240-243
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    • 1988
  • The hexane extract from Nutmeg, the seed of Myristica fragrans significantly inhibited hepatic drug-metabolizing enzyme activity. Through systematic fractionation by $SiO_2$ column and vacuum liquid chromatography monitoring by bioassay, three components, myristicin, (I), licarin-B (II) and dehydrodiisoeugenol (III) were isolated as active principles. Compounds II and III, with a single treatment (200mg/kg, i.p.) showed not only a significant prolongation of hexobarbital-induced sleeping time but also a significant inhibition of aminopyrine N-demethylase and hexobarbital hydroxylase activities in mice. Compounds I and II provoked a sleep episode at a subhypnotic dose of HB, suggesting that they possess CNS-depressant properties.

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Effect of Pretreatment with Nicotinamide on Changes in the Hepatic Metabolizing Enzyme Systme Induced by Streptozotocin (Streptozotocin에 의해 유도된 간 대사효소계의 변화에 미치는 Nicotinamide의 영향)

  • 최종원;손기호;김석환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.3
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    • pp.203-208
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    • 1991
  • The present study was undertaken in order to elucidate the effects of pretreatment with nicotinamide on changes in the hepatic metabolizing enzyme system inducted by streptozotocin (STZ). In rats, STZ(50mg/kg) administered by tail vein caused a significant rise in hepatic aniline hydroxylase and a decrease in aminopyrine N-demethylase when compared to control (p<0.05). Pretreatment with nicotinamice inhibited these effects (p<0.05). Similarly, STZ induced changes in hepatic microsomal cytochrome P-450 activity were inhibited by pretreatment with nicotinamide (p<0.05). However, changes in UDP-glucuronyl transferase and sulfortransferase activity were not significantly different(p>0.05). Pretreatment with nicotinamide also prevented STZ induced increases in glutathion S-tranferase activity when compared to the control(p<0.05). There results suggest that nicotinamide pretreatment suppresses STZ-induced changes in the hepatic metabolizing enzyme system.

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