Relationships between aqueous oxygen concentration and uptake and elimination rates during bioconcentration of hydrophobic chemicals in fish

Opperhuizen, Antoon; Schrap, S. Marca

doi:10.1002/etc.5620060503

Cited by 28 publications

(6 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This view is based on the fact that water flow over the gill lamellae is greater than blood flow by 10-to 30-fold 1191. This interpretation is supported by recent studies showing that oxygen concentrations in ambient water did not influence the uptake and elimination rates of 2,2',5,5'-tetra-and 2,2',4,4',5,5'-hexachlorobiphenyl in guppies (Poecilia reticulata) after aqueous exposure [20].…”

Section: Discussionsupporting

confidence: 73%

A PHARMACOKINETIC ANALYSIS OF THE UPTAKE OF POLYCHLORINATED BIPHENYLS (PCBs) BY GOLDEN SHINERS

Karara¹,

McFarland²

1992

Environ Toxicol Chem

View full text Add to dashboard Cite

A 96-h, static, nonconstant exposure design was used to assess pharrnacokinetic parameters and to identify the rate-limiting process in polychlorinated biphenyl (PCB) uptake by golden shiners (Notemigonus crysoleucus). Fish were exposed individually to I4C-labeled PCBs corresponding to Aroclor 1254 (A1254). After various intervals (2-96 h), fish and water were analyzed for total radioactivity. Uptake of PCBs and decline of the external water concentration were both rapid. A clearance constant-based one-compartment model was used to represent the fish. Model-based equations for PCB concentrations in the fish and in the water were fitted simultaneously to the observed data with the PCNONLINO computer program. The absorption clearance constant was 30.8 m1.h-l .g-' fish, which identified gill blood flow as the uptake rate-controlling process. The model-predicted apparent volume of distribution, V,, and bioconcentration factor, Kb, were 5,280 ml/g fish and 9,059 ml water per gram fish, respectively. The model-predicted elimination rate constant, k,, was 5.84 x h-', corresponding to a t,,? of 4.9 d.

show abstract

Section: Discussionsupporting

confidence: 73%

A PHARMACOKINETIC ANALYSIS OF THE UPTAKE OF POLYCHLORINATED BIPHENYLS (PCBs) BY GOLDEN SHINERS

Karara¹,

McFarland²

1992

Environ Toxicol Chem

View full text Add to dashboard Cite

show abstract

“…The calculation of P for the aqueous stagnant layer, above, suggests that water flow would dominate the resistance to uptake before the aqueous stagnant layer would, although the latter resistance could be important, particularly when ventilation is greater than the basal rate. r', should also limit uptake when it is very low [21] or when the ventilation/perfusion ratio is very small, as occurs during apnea in fish [I].…”

Section: Discussionmentioning

confidence: 99%

Rate‐limiting barriers to xenobiotic uptake by the gill

Hayton

Barron

1990

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Waterborne xenobiotics enter fish and other aquatic species primarily by transfer across the gill epithelium. Potential barriers to uptake include water flow across the gill, diffusion across the gill epithelium and the overlying aqueous stagnant layer and blood flow through the gill (cardiac output). In general, for any particular chemical, only one of the barriers is operative with the resistance offered by the others being negligible. The rate-limiting barrier is determined by the physico-and biochemical properties of the substance: molecular size, lipophilicity, binding to blood proteins and formed elements. The resistance of each barrier is affected differently by variables such as temperature, molecular size, lipophilicity and body size of the animal. When the resistance offered by the gill barriers is low, uptake may be controlled by transfer to storage tissues, e.g., by blood flow to adipose tissue.

show abstract

“…The concentration of the chemical entering the organ is represented by C,, and the plasma concentration leaving the organ is represented by C,/R,, where R, is the tissue plasma concentration ratio [58]. The equations for these models can be written in terms of RC [60,65,66] or fugacity [46,67] parameters. A promising feature of the PBPK approach is the ability to scale the model to other species or body sizes by inserting the appropriate physiological information.…”

Section: Physiological-and Energetics-based Modelsmentioning

confidence: 99%

“…Compared t o compartment models, PBPK models require significantly more data and resources for development. Often the required data are not available because analyzing tissue volumes or taking blood samples from small fish or invertebrates is difficult [61,66]. Due to differences in the physiology of invertebrates, such as open circularity systems, compared to large fish, it may be necessary to modify the PBPK model structure for benthic invertebrates.…”

Section: Physiological-and Energetics-based Modelsmentioning

confidence: 99%

“…These additional sources generally involve the diet of the organism, whether it is sediment detrital material [31,39,44,75,78,79,112,113] or prey for fish [24,46,47,66,106,. The extent of the dietary route depends on the feeding rate [79,113]; assimilation efficiency, which can vary with feeding rate [78]; and concentration in the food [66]. Additionally, food quality, such as lipid content, may alter contaminant transport into the organism [117].…”

Section: Utilizing Kinetic Models In Exposure Assessmentmentioning

confidence: 99%

See 1 more Smart Citation

Toxicokinetics in aquatic systems: Model comparisons and use in hazard assessment

Landrum

Lydy

Lee

1992

Enviro Toxic and Chemistry

346

247

View full text Add to dashboard Cite

-Toxicokinetic models are not constrained by assumptions of equilibrium as are thermodynamic (equilibrium-partitioning) models and are more accurate predictors of toxicant accumulation for non-steady-state exposures and multiple uptake routes. Toxicokinetic models -compartmentbased models, physiological-based models, and energetics-based models-are reviewed and the different mathematical formalisms compared. Additionally, the residue-based toxicity approach is reviewed. Coupling toxicokinetic models with tissue concentrations at which toxicity occurs offers a direct link between exposure and hazard. Basing hazard on tissue rather than environmental concentrations avoids the errors associated with accommodating multiple sources, pulsed exposures, and non-steady-state accumulation. Keywords-Kinetic models Bioaccumulation Tissue residue effects Sediment contaminationHazard assessment INTRODUCTlONAssessment and prediction of toxicant effects on aquatic organisms require evaluation of the extent of organism exposure. Exposure assessment establishes the relationship between environmental toxicant concentrations and organism accumulation while accounting for environmental and biological factors that modify exposure. If the relationships between the amount of toxicant accumulated and the resulting effects are known, then the hazard for a particular exposure regime can be established.Aquatic exposure assessments and predictions have employed mainly steady-state and equilibriumpartitioning models. Early efforts, using simple kinetic models, were designed to provide estimates of steady-state accumulation from water exposures [1,2]. These steady-state estimates were then utilized in hazard assessments based on thermodynamic limits (chemical equilibrium). Such models have been employed with good success for evaluation of general conditions, describing toxicant distribution among ecosystem components and *To whom correspondence may be addressed.identifying components dominating toxicant mass balance. This approach has been best refined using the fugacity concept and applied to describe the importance of sediment as a toxicant source [3] and toxicant distributions within ecosystems [4,5].Although there is a continued focus on equilibrium-partitioning models within regulatory agencies, it is clear that the environment is complex and variable. Therefore, to obtain more accurate predictions and assessments, kinetic models are needed to predict non-steady-state, nonequilibrium accumulation from temporally and spatially varying exposures when the simplifying assumptions of the equilibrium-partitioning models are inappropriate, for example, when multiple sources contribute significantly to accumulation.Kinetic models have been used successfully in pharmacology for decades. Such models permit prediction of the onset of drug action and allow the monitoring of drug clearance and termination of effects. Further, these kinetic models describe changes in tissue concentrations resulting from absorption, distribution, metabolism, a...

show abstract

Relationships between aqueous oxygen concentration and uptake and elimination rates during bioconcentration of hydrophobic chemicals in fish

Cited by 28 publications

References 32 publications

A PHARMACOKINETIC ANALYSIS OF THE UPTAKE OF POLYCHLORINATED BIPHENYLS (PCBs) BY GOLDEN SHINERS

A PHARMACOKINETIC ANALYSIS OF THE UPTAKE OF POLYCHLORINATED BIPHENYLS (PCBs) BY GOLDEN SHINERS

Rate‐limiting barriers to xenobiotic uptake by the gill

Toxicokinetics in aquatic systems: Model comparisons and use in hazard assessment

Contact Info

Product

Resources

About