• 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.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.105-109
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• 2000

The purpose of this study is to investigate on the water quality of the upper region of Wonchun stream located in Suwon city by chemical analysis and EROD-microbioassay methods using rat hepatoma cell line H4IIE. The water samples were collected at 6 sampling sites from sept. to Nov. 1999 and determined the quantitative toxic effects. Higher levels of BO $D_{5}$, CO $D_{Cr}$ and CO $D_{Mn}$ were determined at M6 site where the influent contains domestic and industrial wastewater. EROD activity of water samples was ranged from 3.43$\pm$0.08 to 9.05$\pm$0.10 pmol/mg protein/min. High correlation with EROD activities and COD values was observed. From the results, the upper region of Wonchun stream water area was presumed to be highly polluted with various persistent organic chemicals.s.

• Journal of Environmental Health Sciences
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• v.26 no.3
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• pp.11-17
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• 2000

There are among the most relevant toxic emissions from incinerators such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs). Induction of cytochrome P4501A1 catalyzed 7-ethoxyresorufin O-deethylase(EROD) activity in mammalian cell culture(EROD bioassay) is thought to be a selective and sensitive parameter used for the quantification of dioxin-like components. In this study, the toxic emissions from several school waste incinerators were evaluated by determination of CYPIA catalytic activity and cytotoxicity using cell culture microbioassay. The incinerator residue and soil samples were collected from the schools located in Kyunggi province from April to June 1999. The samples were extracted in a Soxhlet apparatus using toluene for 20 hours. In order to clean-up, concentrated crude extracts were applied to basic alumina column. The EROD activities of extracts in the H4IIE cells were from 1.91$\pm$0.32 ng-TEQ/g to 24.54$\pm$3.48 ng-TEQ/g of biochemical-TEQ value. In soil samples, CYP1A catalytic activity was 0.09~0.64 ng-TEQ/g. EROD bioassay, seems to be a useful short-term bioassay when information about the biological response of complex environmental samples is needed. Although further study is needed, these results indicate that the potent toxic emissions are produced from school waste semi-incinerators.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.170-176
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• 2003

The effect of xenobiotics on cytochrome P450 (CYP) and 7-ethoxyresorufin-O-deethylase (EROD) in hepatopancreatic microsome of surf clam, Coelomactra anti-quata, were investigated. The microsome isolated from the digestive gland of the surf clam, collected from the east coast of Korea, was in vitro exposed to p, p -DDT (0.1,0.4 and 1.0 mM) for 30 min and 2,3,7,8-TCDD (0.01, 0.04 and 0.1 ppb) and PCB-153 (0.01, 0.04 and 0.1 ppb) for 7 hr. In the case of DDT exposure, the CYP content and EROD activity of 1.0 mM exposure group increased up to about 117% and 120% of the DMSO solvent control group after 10 min. exposure, respectively. After 2 hr exposure of TCDD, the CYP content and EROD activity were also induced to the range of 103∼110% and 121∼139%, respectively. The PCB-153 exposure group showed 107∼115% of CYP content and 129∼140% of EROD activity after 2 hr exposure. Three test chemicals apparently induced CYP and EROD activity in the microsome of surf clam. The inducing potentials depend en the test chemicals.

• Toxicological Research
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• v.14 no.4
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• pp.587-594
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• 1998

In order to understand the mechanism if the regulation of CYP 1A1 gene expression and ethoxyresorufin deethylase (EROD) activity in ex vivo system, we have studied the action of TCDD and 3MC in the isolated perfused female rat liver. CYP1A1 mRNA level and EROD activity were measured in rat liver that was isolated and perfused with various chemicals such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3-methylcholanthrene (3MC), 17$\beta$-estradiol (E$_2$), morin. TCDD or 3MC alone perfusion into female rat liver resulted in increase of CYP 1A1 mRNA level and the magnitude of stimulation was six times higher with TCDD treatment than 3MC treatment. However E$_2$ perfusion into female rat liver showed inhibition of CYP 1A1 mRNA level. When 10$^{-8}$ M E$_2$ was administered concomitantly with either 10$^{-9}$ M TCDD or 10$^{-9}$ M 3MC, stimulated CYP 1A1 mRNA by either TCDD or 3MC was inhibited. Morin was examined for its effects on CYP 1A1 mRNA level and result was similar to that was observed with estrogen. EROD activity was also stimulated with either TCDD or 3MC perfusion, and the magnitude of EROD stiumlation was smaller than that of CYP 1A1 mRNA stimulation in response to TCDD or 3MC perfusion. Unlike CYP1A1 mRNA level, stimulation of EROD activity was greater with 3MC than TCDD. Concomitant perfusion either E$_2$ or morin with TCDD or 3MC inhibited 3MC perfusion or TCDD perfusion stimulated EROD activity. These data suggested that TCDD and 3MC might act diffrently in terms of regulation of CYP 1A1 gene expression in rat liver.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.351-357
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• 1998

In order to understand the mechanism of the regulation of CYPIAI gene expression and ethoxy-resorufin deethylase (EROD) activity in ex vivo system, we have studied the action of TCDD and 3MC in theisolated perfused male rat liver. CYPIAI myNA level and EROD activity were measured in rat liver that wasisolated and perfused with va.ious chemicals such as 2,3,7,8-tet.achlorodibenzo-p-dioxin (TCDD), 3-methyl-cholanthrene (3MC), $17{\beta}$-est.adios ($E_2$), morin. TCDD or 3MC alone perfusion into male rat liver resulted in increase of CYPIAI mRNA level and the magnitude of stimulation was one and half times higher with TCDD treatment than 3MC treatment. However $E_2$ perfusion into male rat liver showed slight stimulation of CYPIAI mRNA level. When $10_{-8}$ M $E_2$ was perfused concomitantly with either $10_{-9}$ M TCDD or $10_{-9}$ M 3MC, stimulated CYPIAI mRNA by either TCDD or 3MC was inhibited. Morin was examined for its effects on CYPIAI mRNA level and result was similar to that was observed with estrogen except that morin alone did not change the level of CYPIAI mRNA. EROD activity was also stimulated with either TCDD or 3MC perfusion, and the magnitude of EROD stiumlation was similar to that of CYPIAI mRNA stimulation in response to TCDD or 3MC perfusion. This data is different from the data that we have obtained with female rat liver. Concomitant perfusion either $E_2$ or morin with TCDD or 3MC inhibited 3MC perFusion or TCDD perfusion stimulated EROD activity. These data confirm the hypothesis that TCDD and 3MC might act through the same mechanism of action on the regulation of CYPIAI gene expression in male rat liver.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.179-184
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• 2002

Induction of cytochrome P45O (CYP) and 7-etholqresorufin-O-deethylase (EROD) in the microsome exposed to 3-methylcholan-throne (MC), $\beta$-naphthoflavone (BNF) and phenobarbital-Na (PB) was investigated, Microsome was isolated from digestive gland of clam (Coelomactra antiquata) and then exposed to each chemical in concentration range of 0.1 to 1.0 mM for 7 hours. The CYP content and EROD activity in the microsome exposed to each chemical significantly increased compared to the control group. The overall CYP and EROD induction potency was in order of MC>BNF>PB. The induction response of EROD was two times higher than that of CYP level in the microsome exposed to MC, but the induction response of EROD was slightly higher than that of CYP level in BNF and PB exposure groups.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.185-190
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• 2002

This study was carried out to measure the in vitro interaction of trialkyltin with the microsomal monooxygenase (MFO) system of the clam, Coelomactra antiquata. Cytochrome P450 (CYP) level and 7-ethonvesorufin-O-deethylase (EROD) activity were invetigated in the microsome isolated from digestive gland of the clam (C. antiquata) exposed to tributyltin chloride (TBTC), bis-tributyltinoxide (TBTO) and triphenyltin chloride (TPTC). The specific contents of CYP in clam microsome exposedto 0.4 mM TBTC, TBTO and TPTC for 20 minutes were decreased 52, 72 and $40\%$, respectively, compared to control group. The EROD activities also were inhibited by exposure to TBTO ($92\%$) and TPTC ($85\%$) except for TBTC, The level of CYP and the EROD actintles were decreased according to the OTC exposure concentrations. The toxic effects on the level of CYP and the EROD activities were in order of TPTC>TBTC>TBTO in this study. The measurement of CYP level and EROD activity could be applied as a biomarker for environmental study.

• Toxicological Research
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• v.16 no.4
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• pp.285-291
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• 2000

So far, investigation of environmental pollution has been achieved in field study. This remains the most exhaustive approach, current dimensions of environmental researches and their inherent complexity require that relatively inexpensive and simple laboratory procedures are developed to make possible the screening of large numbers of sites and samples. At this point. microbioassay has been high-lighted. The purpose of this study is to evaluate the water pollution using microbioassay. Two microbioassay methods were optimized and validated for the sensitive and quantitative determination of total toxic effects in the water. EROD(Ethoxyresorufin-O-deethylase) microbioassay was focused to detect PARs, PCBs and dioxinlike components in the water and E-screen assay to xenoestrogens. The EROD microbioassay was executed in rat hepatoma cell line, H4IIE and E-screen assay in MCF7-BUS cell line. Kumho river was selected for this study. 5ι of river water was extracted using combined solid-phase extraction in static adsorption mode with soxhlet extraction. Pollutants adsorbed to the XAD-4 resin were recovered by elution with ethyl acetate and methylene chloride (1 : 9). Toxic effects of extracts were determined by EROD-microbioassay and E-screen assay. EROD activities of water samples were 7.24-72.24 ng/ι MEQ. The estrogenic effect of various water samples is quantitatively evaluated by EEQ. The EEQ of samples range from 0.05 to 6.07 ng-EEQ/ι. These results suggested that Kumho river was highly polluted with organic toxic chemicals.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.131-131
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• 2002

PCBs are wide spread persistent environmental pollutants that exert a broad spectrum of toxic effects. PCBs includes 209 possible congeners differing in extent and position of chlorination of their aromatic rings. In order to understand the toxic mechanism of PCBs, we have tested the effect of PCB on the EROD activity in vivo.(omitted)