Passive dosing: An approach to control mutagen exposure in the Ames fluctuation test

Bougeard, Cynthia; Gallampois, Christine; Brack, Werner

doi:10.1016/j.chemosphere.2010.12.087

Cited by 25 publications

(20 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus when passively dosing HOCs with log K Silicone/Free values of around 1,000 and above, V Water / V Silicone phase ratios less than around 10-20 are typically used [ 9 , 23 -26 ]. For example, Bougeard et al [ 26 ] and Smith et al…”

Section: Step 1: Selection Of a Passive Dosing Phasementioning

confidence: 97%

“…For example, a passive dosing format based on silicone O-rings was applied in the Ames II assay for determining the mutagenicity of amino-and nitro-PAHs in the absence of metabolic activation [ 26 ]. The C Free -based effect concentrations when passive dosing were 3-33 times lower than those based on the nominal spiked concentrations, with the differences increasing for the more hydrophobic compounds due to their enhanced sorption and thus lower availability.…”

Section: Control Of Hydrophobic Compound Exposurementioning

confidence: 99%

See 1 more Smart Citation

The Control of Hydrophobic Compound Exposure in In Vitro Tests for Genotoxicity

Smith

2014

Genotoxicity and DNA Repair

View full text Add to dashboard Cite

Several of the OECD recommended tests for genotoxicity are in vitro tests, involving the use of open plastic vessels and culture plates, rich culture media, or metabolic activation. These result in volatile, sorptive, and biotransformation losses of the test compound, and thus to poorly defi ned exposure. This has implications for the apparent sensitivity of the assay as well as for establishing a reliable relationship between concentration and response. These issues are particularly relevant for hydrophobic organic compounds (HOCs) which are diffi cult to initially dissolve in aqueous media and particularly susceptible to sorptive losses. Therefore, the in vitro genotoxicity testing of HOCs requires techniques that compensate for losses and lead to defi ned and constant dissolved exposure concentrations. Here, passive dosing can play a useful role. Passive dosing involves a dominating reservoir of polymer-sorbed HOC acting as a partitioning source to the test medium, maintaining defi ned and constant dissolved concentrations. This chapter introduces passive dosing for the control of HOC dissolved concentrations during in vitro genotoxicity tests, covering considerations for selecting a suitable passive dosing polymer and its dimensioning, as well as procedures for cleaning and loading the dosing polymer with the test HOC(s).

show abstract

Section: Step 1: Selection Of a Passive Dosing Phasementioning

confidence: 97%

Section: Control Of Hydrophobic Compound Exposurementioning

confidence: 99%

The Control of Hydrophobic Compound Exposure in In Vitro Tests for Genotoxicity

Smith

2014

Genotoxicity and DNA Repair

View full text Add to dashboard Cite

show abstract

“…The freely dissolved concentration in the aqueous medium determines the internal concentration at the biological receptor. Nominal concentrations are no reliable measure for exposure and can be orders of magnitude greater than freely dissolved concentrations, depending on the test system and compound absorption properties (Bougeard, Gallampois, & Brack, 2011). This is due to the fact that lipophilic chemicals adsorb to the walls of test vessels, medium components, test organisms, and cells or subcellular compartments, resulting in depletion below the nominal concentration (Escher & Hermens, 2004).…”

Section: Effect Concentrations Of Chemosensitisers In Different Test mentioning

confidence: 99%

Is chemosensitisation by environmental pollutants ecotoxicologically relevant?

2015

Self Cite

View full text Add to dashboard Cite

“…To date passive dosing has been used in different in vitro tests, leading to increases in apparent assay sensitivity compared with solvent spiking due to the rigorously defined and stable exposure concentrations [23,26]. Passive dosing has also recently been applied in the Ames II assay for measuring the mutagenicity of amino-and nitro-PAHs in the absence of metabolic activation [25]. Here, effect concentrations based on passive dosing partitioning were 3-33 times lower than those based on nominally spiked concentrations, the discrepancy increasing with higher hydrophobicity.…”

Section: Introductionmentioning

confidence: 98%

“…Passive dosing is one approach to achieve defined and constant dissolved concentrations during in vitro assays [23][24][25][26]. Here, a biologically inert polymer, such as silicone, is loaded with hydrophobic test compound and introduced into the medium where it functions as a partitioning source and compensates for losses and sorption during the test [27].…”

Section: Introductionmentioning

confidence: 99%