• Journal of Aquaculture
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• v.19 no.2
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• pp.90-94
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• 2006

The effects of formalin on mixed function oxygenase (MFO) system and stress-response were investigated in olive flounder (Paralichthys olivaceus). Olive flounder was exposed to formalin at the concentration of 300 ppm for 1, 2, 4 and 16 h. Levels of stress-response enzymes together with total protein, glucose and osmolality were quantitatively determined in blood, and the activities of phase I (cytochrome P450, ethoxyresorufin deethylase) and phase II (glutathione S-transferase) hepatic enzymes were also determined. Since the formalin-exposure for 16 h resulted no significant changes in aspartate aminotransferase and alanine aminotransferase, specific enzymes for liver damage, it was thought that it did not cause hepatic tissue damage at the concentration of 300 ppm. However, hepatic MFO system was induced at 1 to 4 h, and stress response was induced after 16 h of exposure. Moreover, it is considered that the depression of MFO activity after 16 h of exposure may not be adaptation to formalin, but toxic response. These results suggest that low concentration of formalin does not cause hepatic tissue damage of fish, but could induce MFO and stress response.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1248-1258
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• 2019

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.265-272
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• 1998

The effects of mixtures of diazinon(DA;5mg/kg), toxaphene(TOX;40mg/kg) and/or endrin(END; 5mg/kg) on the hepatic mixed-function oxygenase(MFO) system were stuided in ICR mice(18~22g) by oral intubation daily for 7 days. In general, TOX and TOX-containing mixtures were found to induced the metabolism of aminopyrine(22~60%), aniline(42~85%), phenacetin(145~194%) and benzo [a]pyrene(158~210%), and pentobaribtal biotransformation in the 9,000g liver supernatants and to increased the hepatic cytochrome p-450 contents(47~89%). Results of these may be, at least in part, associated with the MFO system. TOX pretreatment increased the aliesterase activity in the serum and liver homogenates and supernatants by 23~145%. The toxicity of TOX and TOX-containing mixtures would be lower than that of diazinon because of TOX-induced increase in the metabolism of diazinon(DA) or diazioxon(DO) and capability of TOX to stimulate the metabolism of diazinon and diazioxon and provide a pool of non-critical enzymes. These results suggest that this information might be helpful in the evaluation of the potential hazard due to occupational and/or environmental exposures to pesticides and their mixtures.

• 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 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 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.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.29 no.1
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• pp.168-173
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• 2000

The purpose of this study was to investigate the changes of microsomal mixed function oxidase (MFO) and xanthine oxidase activities (XOD) in the liver of rats exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to a normal and microwave exposed(MW) groups; microwave exposed groups were divided into two groups; microwave (MW) group and green tea(GT) gropu which were fed distilled water and green tea extracts during experimental periods, respectively. Rats were irradiated with microwave at the frequency of 2.45 GHz for 15min and rats wre sacrificed at the 4th day of the microwave irradiaton. The hemoglobin level of GT group was higher than that of the normal gropu and MW group, but the hematocrit value was not significantly different among all experimental gropus. The activity of serum GOT of MW group was significantly increased but that of GT group was similar to normal group. Activities of GPT were not significantly different among all experimental groups. Liver XOD activity was significantly increased in the microwave exposed groups but green tea normalized the XOD activity. The activity of hepatic microsomal cytochrome P450 was significantly increased in MW group compared to normal group and that of GT group was similar to that of the normal group. The activity of hepatic microsomal NADPH-cytochrome P450 reductase was also significantly increased in MW group compared to normal group, but that of GT group was similar to that fo the normal group. In conclusion, the activities of MFO and XOD were elevated by microwave irradiaton, but the activation of MFO system as well as the damage of the liver by microwave were reduced by green tea supplementation.

• Toxicological Research
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• v.4 no.2
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• pp.107-115
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• 1988

The effects of altering the hepatic mixed-function oxidase(MFO) activities on the acute toxicity of parathion were examined in female rats. Phenobarbital sodium pretreatment (50mg/kg/day, i.p.) for 4 consecutive days has resulted in significant decreases in the toxicity of parathion (2 or 4 mg/kg, i.p.) as determined by lethality and cholinesterase activities wheras the toxicity arising from a single dose of CCl4(2 mmol/kg, i.p.) 24 hr prior to parathion challenge was potentiated.

• 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.