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Bioconcentration of aromatic amines in fish: A possible influence of biotransformation
146
Abstracts
to a complex mixture of contaminants extracted from a sediment collected from a polluted area of Puget Sound, WA. Additionally, during the timeand dose-responses studies, the levels of fluorescent aromatic compounds (FACs) were measured in the bile of the fish, both to provide an estimation of contaminant exposure and to evaluate the time- and dose-responses of this measure. The results showed that the balance of xenobiotic metabolism, as reflected in activities of XMEs, is altered by exposure to environmental contaminants. Moreover, the results provided substantial validation for the use of measurements of hepatic aromatic hydrocarbon hydroxylase activities and levels of FACs in bile as biomarkers of exposure of benthic fish to environmental contaminants.
Bioconeentration of Aromatic Amines in Fish: A Possible Influence of Biotransformation. WATZE DE WOLF, EDDY YEDEMA & JOOP HERMENS. Research Institute of Toxicology, Section Environmental
Toxicology, University of Utrecht, PO Box 80176, 3508 TD Utrecht, The Netherlands. Numerous studies have shown that the uptake, transport and bioconcentration of a chemical in fish increases with its octanol-water partition coefficient (Kow). Most correlations are based on rather stable, non-polar chlorinated hydrocarbons. Less stable chemicals that are more susceptible to biotransformation may bioconcentrate to a much lower extent. As part of a research project to study the influence of biotransformation on bioconcentration in fish, we have measured uptake and elimination rate constants of several chloroanilines in guppy (Poecilia reticulata). During the accumulation period, guppies were exposed to a mixture of seven chloroanilines (four trichloroanilines, two tetrachloroanilines and pentachloroaniline) in a semi-static exposure system. After 11 days the remaining fish were transferred to clean water to study elimination kinetics. At regular time-intervals water- and fish-samples were taken and the chloroanilines were analyzed by gas chromatography. Uptake rate constants (kl) were calculated based on the bioconcentration (BCF) value and the measured elimination rate constants (k2). The results showed that: (1) The elimination rate constants of chloroanilines are higher and BCF-values are lower compared with literature data for chlorobenzenes and chloronaphthalenes with similar octanol-water partition coefficients (Kow). (2) Mass balances indicate that great amounts of the introduced chloroanilines are lost during the accumulation phase. (3) Chloroanilines with equal Kow differ in their BCFvalue.
Abstracts
147
The high value for the elimination rate constants in addition to the relatively low BCF values, and also the high losses of test compound during accumulation, are indications that biotransformation is a dominant factor in the toxicokinetic behaviour of chloroanilines in fish.
Elevation of Glutathione Transferase in Molluscs in Response to Xenobiotics. A. C. G A R R O O D , " C. A K R O Y D , ° M. BEVERLEY," M. BORYSLAWSKYJ," J. T. PEARSON" & D. W O O D H E A D ) "Department of Chemistry, Huddersfield Polytechnic', Queensgate, Huddersfield, UK & hCross & Bevan Water Consultants, 24 Sunfield Drive, Stanningley, Leeds, UK. Glutathione transferase (GST) has been implicated in the metabolism of a wide range of xenobiotics. Previous studies have shown an increase in specific activity in GST in the freshwater mussel Sphaerium corneum in response to dieldrin. In these studies we have studied this change in response to a range of xenobiotics including dieldrin, lindane, permethrin, tributyltin oxide, Diazinon and Micoprop. The elevations obtained are compared to fluctuations in specific activity induced by environmental variables such as temperature, pH, season, dissolved oxygen, lipid content, reproductive status, season, and size of individual organism. The results are discussed in relation to use of the enzyme as a biochemical index of stress in freshwater and marine biota.
Induction of Hepatic Xenobiotic Metabolising Systems in Plaice: Determination by Enzymic Activity and lmmnnoblot Analyses. S. GEORGE, M. LEAVER, G. B U C H A N A N & D. CLARKE. MERC Unit ~1 Aquatic Biochemisto,, University of Stirling, FK9 4LA, UK. Hepatic cytochromes P-450 (P-450s), U DP-glucuronyltransferase (GTs) and glutathione S-transferases (GSTs) are all multigene families of enzymes, the isozymes have overlapping substrates specificities and they are differentially induced by organic compounds. Analysis of this induction profile provides a useful method of assessing sublethal pollutant effects in marine and estuarine fish. Due to the labile nature of the enzymes, determination of enzyme activities requires rapid transportation to the laboratory and so immunoassay is the method of choice. Antibodies have been raised to these enzymes and comparative data are presented for enzyme activity determinations and immunoassays of these enzymes in fish experimentally exposed to a variety of inducing compounds.
Abstracts
to a complex mixture of contaminants extracted from a sediment collected from a polluted area of Puget Sound, WA. Additionally, during the timeand dose-responses studies, the levels of fluorescent aromatic compounds (FACs) were measured in the bile of the fish, both to provide an estimation of contaminant exposure and to evaluate the time- and dose-responses of this measure. The results showed that the balance of xenobiotic metabolism, as reflected in activities of XMEs, is altered by exposure to environmental contaminants. Moreover, the results provided substantial validation for the use of measurements of hepatic aromatic hydrocarbon hydroxylase activities and levels of FACs in bile as biomarkers of exposure of benthic fish to environmental contaminants.
Bioconeentration of Aromatic Amines in Fish: A Possible Influence of Biotransformation. WATZE DE WOLF, EDDY YEDEMA & JOOP HERMENS. Research Institute of Toxicology, Section Environmental
Toxicology, University of Utrecht, PO Box 80176, 3508 TD Utrecht, The Netherlands. Numerous studies have shown that the uptake, transport and bioconcentration of a chemical in fish increases with its octanol-water partition coefficient (Kow). Most correlations are based on rather stable, non-polar chlorinated hydrocarbons. Less stable chemicals that are more susceptible to biotransformation may bioconcentrate to a much lower extent. As part of a research project to study the influence of biotransformation on bioconcentration in fish, we have measured uptake and elimination rate constants of several chloroanilines in guppy (Poecilia reticulata). During the accumulation period, guppies were exposed to a mixture of seven chloroanilines (four trichloroanilines, two tetrachloroanilines and pentachloroaniline) in a semi-static exposure system. After 11 days the remaining fish were transferred to clean water to study elimination kinetics. At regular time-intervals water- and fish-samples were taken and the chloroanilines were analyzed by gas chromatography. Uptake rate constants (kl) were calculated based on the bioconcentration (BCF) value and the measured elimination rate constants (k2). The results showed that: (1) The elimination rate constants of chloroanilines are higher and BCF-values are lower compared with literature data for chlorobenzenes and chloronaphthalenes with similar octanol-water partition coefficients (Kow). (2) Mass balances indicate that great amounts of the introduced chloroanilines are lost during the accumulation phase. (3) Chloroanilines with equal Kow differ in their BCFvalue.
Abstracts
147
The high value for the elimination rate constants in addition to the relatively low BCF values, and also the high losses of test compound during accumulation, are indications that biotransformation is a dominant factor in the toxicokinetic behaviour of chloroanilines in fish.
Elevation of Glutathione Transferase in Molluscs in Response to Xenobiotics. A. C. G A R R O O D , " C. A K R O Y D , ° M. BEVERLEY," M. BORYSLAWSKYJ," J. T. PEARSON" & D. W O O D H E A D ) "Department of Chemistry, Huddersfield Polytechnic', Queensgate, Huddersfield, UK & hCross & Bevan Water Consultants, 24 Sunfield Drive, Stanningley, Leeds, UK. Glutathione transferase (GST) has been implicated in the metabolism of a wide range of xenobiotics. Previous studies have shown an increase in specific activity in GST in the freshwater mussel Sphaerium corneum in response to dieldrin. In these studies we have studied this change in response to a range of xenobiotics including dieldrin, lindane, permethrin, tributyltin oxide, Diazinon and Micoprop. The elevations obtained are compared to fluctuations in specific activity induced by environmental variables such as temperature, pH, season, dissolved oxygen, lipid content, reproductive status, season, and size of individual organism. The results are discussed in relation to use of the enzyme as a biochemical index of stress in freshwater and marine biota.
Induction of Hepatic Xenobiotic Metabolising Systems in Plaice: Determination by Enzymic Activity and lmmnnoblot Analyses. S. GEORGE, M. LEAVER, G. B U C H A N A N & D. CLARKE. MERC Unit ~1 Aquatic Biochemisto,, University of Stirling, FK9 4LA, UK. Hepatic cytochromes P-450 (P-450s), U DP-glucuronyltransferase (GTs) and glutathione S-transferases (GSTs) are all multigene families of enzymes, the isozymes have overlapping substrates specificities and they are differentially induced by organic compounds. Analysis of this induction profile provides a useful method of assessing sublethal pollutant effects in marine and estuarine fish. Due to the labile nature of the enzymes, determination of enzyme activities requires rapid transportation to the laboratory and so immunoassay is the method of choice. Antibodies have been raised to these enzymes and comparative data are presented for enzyme activity determinations and immunoassays of these enzymes in fish experimentally exposed to a variety of inducing compounds.