PCB isomers and congeners: Induction of aryl hydrocarbon hydroxylase and ethoxyresorufin O-deethylase enzyme activities in rat hepatoma cells

Sawyer, T.; Safe, Stephen

doi:10.1016/0378-4274(82)90142-4

Cited by 179 publications

(82 citation statements)

References 12 publications

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“…This ensures proper replication of samples and allows for increased numbers of samples to be tested. In the original H4IIE cell line bioassay, cell monolayers were grown in 60-to 100-mm-diameter petri plates or in smaller culture flasks (e.g., 25 cm 2 ) prior to dosing (Bradlaw et al, 1980;Sawyer and Safe, 1982;. Multi-well microtiter plates are more commonly used in current investigations (Tysklind et al, 1994;Sanderson et al, 1996;Whyte et al, 1998).…”

Section: Platingmentioning

confidence: 99%

“…At this point, aseptic technique is no longer necessary and the assay can be performed on the benchtop (this is also true for the EROD assay; see later discussion). Cells are harvested by trypsinization, scraping, or a combination of both (Bradlaw and Casterline, 1979;Sawyer and Safe, 1982). A cellular protein pellet produced after centrifugation (e.g., 10,000 × g for 5 min) is resuspended in buffer.…”

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

“…A cellular protein pellet produced after centrifugation (e.g., 10,000 × g for 5 min) is resuspended in buffer. AHH activity can be measured (Sawyer and Safe, 1982) or the resuspended pellet can be further centrifuged (105,000 × g for 60 min) to isolate the microsomal fraction where the P-450 enzymes reside (Nebert and Gelboin, 1968b). The enzymatic activity of AHH is usually measured fluorometrically.…”

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

“…A portion of the organic extract is then extracted with 1 N NaOH (Sawyer and Safe, 1982) and the fluorescence of this fraction is measured at 396 nm excitation and 517 nm emission. Protein determination can be carried out before or after measurement of 3-hydroxybenzo[a]pyrene using the method of Lowry (1951) or Bradford (1976).…”

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

“…The H4IIE EROD assay is a modification of the method of Pohl and Fouts (1980). Cell harvesting and preparation of a microsomal fraction were originally performed similar to the AHH bioassay (Sawyer and Safe, 1982;Keys et al, 1986), but now the reaction is generally carried out in the same microtiter plate used for chemical dosing, based on the work of Kennedy et al (1993). After incubation, plates are washed 2-3 times with distilled water (Tysklind et al, 1994) or with PBS (pH 7.4) if a live cell assay is to be performed (see later discussion; Whyte et al, 1998).…”

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

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The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

Whyte

Schmitt

Tillitt

2004

Critical Reviews in Toxicology

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ABSTRACT:The H4IIE cell bioassay has proven utility as a screening tool for planar halogenated hydrocarbons (PHHs) and structurally similar chemicals accumulated in organisms from the wild. This bioassay has additional applications in hazard assessment of PHH exposed populations. In this review, the toxicological principles, current protocols, performance criteria, and field applications for the assay are described. The H4IIE cell bioassay has several advantages over the analytical measurement of PHHs in environmental samples, but conclusions from studies can be strengthened when both bioassay and analytical chemistry data are presented together. Often, the bioassay results concur with biological effects in organisms and support direct measures of PHHs. For biomonitoring purposes and prioritization of PHH-contaminated environments, the H4IIE bioassay may be faster and less expensive than analytical measurements. The H4IIE cell bioassay can be used in combination with other biomarkers such as in vivo measurements of CYP1A1 induction to help pinpoint the sources and identities of dioxin-like chemicals. The number of studies that measure H4IIE-derived TCDD-EQs continues to increase, resulting in subtle improvements over time. Further experiments are required to determine if TCDD-EQs derived from mammalian cells are adequate predictors of toxicity to non-mammalian species. The H4IIE cell bioassay has been used in over 300 published studies, and its combination of speed, simplicity, and ability to integrate the effects of complex contaminant mixtures makes it a valuable addition to hazard assessment and biomonitoring studies.

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Section: Platingmentioning

confidence: 99%

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

See 3 more Smart Citations

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

Whyte

Schmitt

Tillitt

2004

Critical Reviews in Toxicology

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Competitive behavior in the interactive toxicology of halogenated aromatic compounds

Petrulis

Bunce

2000

J. Biochem. Mol. Toxicol.

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Limitations of the toxic equivalency factor approach for risk assessment of TCDD and related compounds

Safe

1997

Teratog. Carcinog. Mutagen.

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Halogenated aromatic hydrocarbons (HAHs), such as polychlorinated biphenyls (PCBs), dibenzo‐ρ‐dioxins (PCDDs), and dibenzofurans (PCDFs), are industrial compounds or by‐products that have been widely identified as environmental contaminants. Hazard and risk assessment of complex HAH mixtures have utilized a toxic equivalency factor (TEF) approach, where the toxic equivalents (TEQs) of any mixture are equal to the sum of the concentration of individual (i) congeners times their potencies (TEFi) relative to 2,3,7,8‐tetrachlorodibenzo‐ρ‐dioxin (TCDD, TEF = 1.0). TEQ = Σ [PCDDi] · TEFi + Σ [PCDFi] · TEFi + Σ [PCBi] · TEFi The TEQ (or TCDD equivalents) can be readily calculated from analytical data and provides an estimate of the toxicity of any mixture containing HAHs. Several in vivo and in vitro studies with some PCDD/PCDF and PCB mixtures have demonstrated correlations between experimentally determined and calculated TEQs. However, results of several studies have also shown that for specific responses, the TEQ for some HAH mixtures are non‐additive. For example, PCB mixtures and individual PCB congeners such as 2,2′,4,4′,5,5′‐hexachlorobiphenyl inhibit toxic and biochemical responses induced by TCDD and related compounds. Another problem associated with hazard and risk assessment of background exposure to HAHs is the relative contribution of trace levels of HAHs (exodioxins) compared to relatively high exposure to naturally occurring aryl hydrocarbon receptor (AhR) agonists, which act through the same mechanistic pathway. Teratogenesis Carcinog. Mutagen. 17:285–304, 1997/98. © 1998 Wiley‐Liss, Inc.

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PCB isomers and congeners: Induction of aryl hydrocarbon hydroxylase and ethoxyresorufin O-deethylase enzyme activities in rat hepatoma cells

Cited by 179 publications

References 12 publications

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

Competitive behavior in the interactive toxicology of halogenated aromatic compounds

Limitations of the toxic equivalency factor approach for risk assessment of TCDD and related compounds

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