• Korean Journal of Environmental Biology
• /
• v.24 no.2 s.62
• /
• pp.195-200
• /
• 2006

The response of hepatic mixed function oxygenase (MFO) system was investigated in olive flounder exposed to formalin. Hepatic microsome of olive flounder incubated in vitro with formalin demonstrated the induction of cytochrome P450 (CYP), ethoxyresorufin deethylase (EROD), cytochrome P450 reductase (P450R) and cytochrome b5 reductase (b5R) activity. In addition, olive flounder was exposed to 100, 300 and 500 ppm of formalin for 1 h and then transferred to a flow-through type of 1000 L aquarium. Hepatic MFO enzyme activity was determined for 72 h. As the result, hepatic CYP, P450R and EROD activities increased following exposure of formalin, but b5R and GST showed no significant change. These results imply that CYP and P450R can be considered as main hepatic enzymes involving in detoxification of formalin.

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2001.12a
• /
• pp.101-102
• /
• 2001

• Journal of Food Hygiene and Safety
• /
• v.11 no.4
• /
• pp.291-297
• /
• 1996

The role of cytochrome P-450 2E1 (P450 2E1) in the early phase of alcoholic fatty liver was examined. Female rats were pretreated with either allyl sulfide (200 mg/kg, po), disulfiram (500 mg/kg, po), YH 439 (250 mg/kg, po) or pyrazine (200 mg/kg/day$\times$2 days, ip). Marked changes in carbon tetrachloride-induced hepatotoxicity and caboxyhemoglobin (COHb) elevation due to dichloromethane administration were observed in rats treated with one of the P450 2E1 modulators. A single dose of ethanol (6 g/kg, po) increased the hepatic triglyceride contents approximately 2 fold, which was inhibited completely by YH 439 pretreatment. However, the other P450 2E1 modulators failed to alter the ethanol-induced hepatic triglyceride accumulation. In vitro hepatic microsomal enzyme activity was determined in 4 week old premature and 12 week old adult rats. Aminopyrine-N demethylation was not different, but p-nitrophenol hydroxylation and p-nitroanisole O-demethylation were significantly higher in premature rats. However, no difference in the triglyceride accumulation induced by an intraperitoneal dose of ethanol (3 g/kg) was noted between premature and adult rats. The results suggest that the P450 2E1 activity dose not play an important role in the induction of acute alcoholic fatty liver.

• The Korean Journal of Zoology
• /
• v.27 no.4
• /
• pp.221-230
• /
• 1984

The activities of aminopyrine demethylase which is marker enzyme of the microsomal drug-metabolizing system, NADPH-cytochrome a reductase and glutathione peroxidase were measured during the course of liver regeneration after about seventy percent hepatectomy in Wistar rats. In addition, the extent of lipid peroxidation and contents of cytochrome P-450 were also measured. Partial hepatectomy produced a significant depression in aminopyrine demethylase, to reach a minium about 24 hours after operation, but this activity was increased to normal value during regeneration. On the other hand, in sham-operated animals, this showed no change. All the activities of NADPH-chrome P-450 contents of liver microsomes were rapidly decreased at the early stage of regeneration. These values returned to normal after 7 days. By contrast, the activity of glutathione peroxidase was nearly unchanged. According to these results, at the early stage of regeneration, the decrease of cytochrome P-450 and NADPH-cytochrome c reductase activity lead to decrease of lipid peroxidation and drug metabolizing enzyme activity. But these phenomena were not detected after 7 days of regeneration.

• Microbiology and Biotechnology Letters
• /
• v.38 no.3
• /
• pp.227-234
• /
• 2010

Cytochrome P450 enzymes which require the supply of electrons from NAD(P)H have a great biotechnological impact as they catalyze valuable reactions on a vast variety of substrates. However, very limited biotechnological application has been reported so far due to their functional complexity, limited stability (instability) and, in most cases, low catalytic activity. In this present review, we introduce some possibilities for improving their defect by exploring electron transport system and substrate flexibility in field of Streptomyces cytochrome P450.

• Korean journal of applied entomology
• /
• v.32 no.2
• /
• pp.225-235
• /
• 1993

This study was carried out to investigate effects of diazinon, an organophosphate, and nicotine, a plant~originated toxic chemical, on larval mortality and activity of cytochrome P-45D monooxygenases, a major detoxifwation enzyme system, in Helicoverpa assulta and Spodoptera exigua. Diazinon treatment gave a higher mortaliLy to H. assulta larvae than S. exigua larvae. In contrast to the case of diazinon, nicotine caused a higher mortahty to S. exigua than to H. assulla larvae. It was partly due to the fact that nicotine induced the actiVIty of midgut cytochrome P-450 monooxygenases (MFO) more than diazinon did in If assulta larvae. When If. aSSlllta larvae were reared on their host p\am. NicotwlIa tuoocum leaves, other componentS were mostly metabolized with the exception of dietary nicotine.

• Journal of Life Science
• /
• v.13 no.6
• /
• pp.879-888
• /
• 2003

In order to measure the enzyme activity of 5-epi-aristolochene hydroxylase, one of cytochrome P450 (P450) enzymes in eicitor-treated pepper cell, we used in vivo assay method and demonstrated a dramatic suppression of the activity by P450-inhibitors, ancymidol and ketocornazole. Using RT-PCR method with degenerate primer of the well conserved domains found within most P450-enzymes, and using cDNA library screening method, one distinct cDNA, being designated P450Hy01, was successfully isolated from elicitor-treated pepper cells. P450Hy01 mRNA was all induced in elicitor-treated cells whereas never induced in control cells. Moreover, levels of P450Hy01 expression were highly correlated with the levels of extracellular capsidiol production by different elicitors in cell cultures. P450Hy01 transcript was also induced by several other elicitors such as, cellulase, arachidonic acid, jasmonic acid, yeast extract as well as UV stress. P450Hy01 sequence contained high probability amino acid matches to known Plant P450 genes and ORF with a conserved FxxGxRxCxG heme-binding domain. P450Hy01 cDNA showed 98% of homology in sequence of nucleotide as well as amino acid to 5-epi-aristolochene-1, 3-hydroxylase (5EAl, 3H) which has been isolated in tobacco cells, suggesting that P450Hy01 is prominent candidate gene for P450-enzyme encoding 5EAl, 3H in pepper cell.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.149.3-150
• /
• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

• Toxicological Research
• /
• v.5 no.1
• /
• pp.17-25
• /
• 1989

Chronic adminstraction of morphine to adult male rats has long been known to lower hepatic cytochrome p-450 content and its dependent mixed-function oxidase activity. Following the treatment of adult male rats with morphine, pethidine pentazocine and codeine and also by concomitant adminstration of naloxone activities of microsomal electron transfer in the adult male rats were examined. In present study, the acute treatment of mature male rats with a dose of narcotic drugs higher than that used chronically also reduces their hepatic cytochrome p-450.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.1
• /
• pp.21-26
• /
• 1996

본 연구는 streptozotocin 유발 당뇨쥐에서의 MFO계활성 변화 및 이에 지질과산화를 관찰하고자 체중이 140kg 내외의 Sprague-Dawley 종 흰쥐 숫컷을 대조군과 당뇨 유발 시험군으로 나누어 4주간 사육하였다. 당뇨군은 STZ로 당뇨를 유발시켰으며 당뇨 유발 6일후 쥐를 희생기켜 간조직 및 폐조직 microsome 중의 cytochrome $P_{450}$ 및 cytochrome $b_[5}$ 함량과 NADPH-cytochrome $P_{450}$ reductase 활성도를 측정하고 아울러 microsome내의 지질과산화물을 측정하여 다음과 같은 결과를 얻었다. 실험군간에 식이 섭취량은 차이가 없었으나, 체중 증가량과 식이 효율은 당뇨군이 STZ군에 비해 현저하게 감소하였다. 간장 및 폐조직의 무게는 대조군과 당뇨군간에 유의적인 차이는 없었다. 간조직 및 GP조직 중의 cytochrome $P_{450}$ 함량은 대조군에 비해 당뇨군이 150%, 175%씩 증가하였다. 간조직 및 폐조직 중의 cytochrome $b_{5}$은 대조군에 비해 당뇨군이 53%,116%씩 각각 증가하였다. 간조직에서의 NADPH-cytochrome $P_{450}$ reductase 활성은 당뇨군이 대조군에 비해 46% 증가하였으며, 폐조직에서는 75%증가하였다. 지질과산화물가는 당뇨군이 대조군에 비해 간족에서는 약 95% 높았으며 폐조직에서는 73%높았다. 이상의 결과에서 STZ 유발 당뇨쥐에서는 MFO system의 활성도가 대조군에 비해 현저하게 증가되고 지질과산화반응이 같으 srudgid이 촉진되었으며 폐조직에서도 간조직에서와 비슷한 경향이었다. 이러한 것은 당뇨군에서는 MFO system의 활성증가로 free radical 생성이 증가되고 그 결과 지질과산화가 촉진되었다고 볼 수 있다.