• Korean journal of applied entomology
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• v.32 no.3
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• pp.291-299
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• 1993

Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d;et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

• Journal of Nutrition and Health
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• v.23 no.1
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• pp.11-18
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• 1990

Sprague-Dawley male rats were fed the diet of p/s 4.0(soybean oil : I), p/s 0.08(Beef tallow : II) at the level of 15% fat until 8 weeks after weaning. I & II groups were divided into 4 sub-groups by diets with or without 0.3% butylated hydroxytoluene(BHT). 2-AAF was injected at the age of $5_{1/2}$, 6, $5_{1/2}$, 7 weeks. MFO system enzyme(cytochrome p-450, cytochrome p-450 reductase, cytochrome b5) activities and lipid peroxide were determined from isolated liver microsome. 2-AAF injected young rats had growth retardatiion. Lipid peroxide values were not influenced greatly by dietary fat, 2-AAF and BHT. Cytochrome p-450 contents were increased in I-BHT-AAF & II-AAF groups by 2-AAF and its contents were not affected by BHT. But cytochrome p-450 and cytochrome p-450 reductase were not increased in soybean oil diet ybean oil groups. Cytochrome b5 was not influenced by dietary fat, 2-AAF and BHT. Cytochrome p-450 and lipid peroxide, cytochrome p-450 reductase and cytochrome b5, which transfer to MFO system, appeared to have positive correlations(r=0.2474, r=0.2475, p<0.05) each other. This result suggests that MFO system metabolizing 2-AAF was influenced by dietary fats and BHT. 2-AAF induced growth retardation in young rats.

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

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.195-200
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• 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
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• 2001.12a
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• pp.115-116
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• 2001

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.171-176
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• 2004

Nonyphenol (NP) used actively as non-ionic surfactant is classified as one of most potent endocrine disrupting chemicals. Effects of NP on mixed function oxygenase (MFO) system in rockfish (Sebastes schlegeli) were investigated for seven days after intraperitoneal injection (10 and 25 mg $kg^{-1}$). Hepatosomatic index (BSI) of fishes exposed to NP of 25 mg $kg^{-1}$ was significantly reduced compared to those in control group. NP exposure enhanced cytochrome P450 levels in the fish liver, while 7 ethoxyresorufin-O-deethylase (EROD) activity was inhibited. NP exposure levels in this study were much higher than those found in the coastal environment of Korea. Effects on HSI and liver MFO system, which is involved in steroid hormone metabolism, imply that W may influence on reproduction of fish by not only hormone receptor mediated response but also through effects on the MFO system.

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

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.45-50
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• 2003

This study was conducted to understand the role of oxidative enzyme cytochrome $P_{450}$ in the bioactivation of benfuracarb and to know metabolites of benfuracarb by cytochrome $P_{450}$. The bimolecular imhibition rate constant $(k_i)$ of benfuracarb on acetylcholinesterase (AChE) was as low as $1.1{\times}10^3\;M^{-1}\;min^{-1}$, suggesting that benfuracarb should be activated for its toxic action. The potency of benfuracarb on AChE in the oxidase system (cytochrome $P_{450}$ + NADPH) in vitro was 10-fold higher than that of control (cytochrome $P_{450}$). Such a similar result was also found in the oxidase + PBO system. In vivo the $I_{50}$ of benfuracarb was 22.7mg $kg^{-1}$, but pie-treatment of piperonyl butoxide (PBO) reduced the $I_{50}$ by >100mg $kg^{-1}$. This result suggests that cytochrome $P_{450}$ was involved in the activation of benfuracarb. Using microsomal oxidase system, metabolites of benfuracarb were elucidated. Fifty-eight percent of benfuracarb was converted to carbofuran, a major toxic metabolite, in the oxidase system, while only less than two percent of benfuracarb was converted to carbofuran in the oxidase + PBO system. These results also suggest that cytochrome $P_{450}$ was involved in the activation of benfuracarb. Overall results indicate that cytochrome $P_{450}$ could be involved in the bioactivation of benfuracarb to carbofuran.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.18-25
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• 2003

Effects of tributyltin chloride (TBTC) in vitro on mixed function oxygenase (MFO) system on liver microsome of eight marine fish species were investigated. To determine the effects on MFO system, cytochrome P45O (CYP) and cytochrome b5 con-tents, activities of two reductases (NADH-cytochrome b5 reductase and NADPH-cy-tochrome P450 reductase) and four dealkylation enzymes (EROD, PROD, MROD and ECOD) were measured in fish microsoms exposed to TBTC for 20 min. The WP content was reduced to 10% of the control group in 6 out of 8 species exposed to TBTC, whereas there was no significant change in the cytochrome bs content. the response of NAD(P)H dependant reductases depended on fish species. The dealkylation enzyme activities in microsome were also apparently inhibited by TBTC. The degree of inhibition was different among fish species and four enzymes. The EROD activities in eight species were decreased to the range of 1∼65% of control group.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.177-183
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• 2004

Cytochrome P45O (CYP) contents and 7-ethoxyresorufin-O-deethylase (EROD) activity were determined in hepatic microsome of olive flounder (Paralichthys olivaceus) exposed to tributyltin chloride (TBTC), tributyltin oxide (TBTO), and triphenyltin chloride (TPTC). In addition, effects of in vivo (intraperitoneal injection of 7.5 mg $kg^{-1}$ BW) exposure of flounder to TPTC on CYP, NADPH cytochrome c reductase, NADH cytochrome b5 yeductase and EROD levels were measured. In in vitro exposure of hepatic microsome to organotins, TBTC, TBTO and TPTC reduced CYP contents and inhibited EROD activity. The TPTC was the strongest inhibitor, which is followed by TBTO and TBTC. The degree of inhibition, especially EROD acitivity, depended on the exposure duration. In addition, all the target enzymes in flounder were inhibited by TPTC with the in vivo exposure to TPTC. As EROD activity was the most sensitive to the inhibitions and demonstrated good reproducibility of the results, it could be used as a helpful tool toy monitor effects of organotin compounds on mixed funciton oxygenase system in marine fish.