Analysis of Polychlorinated Dibenzo-P-Dioxins and Dibenzofurans

Rappe, Christoffer; Bergqvist, Per-Anders; Buser, Hans-Rudolf; Garå, Anders; Marklund, Stellan; Nygren, Martin

doi:10.1007/978-94-009-6765-6_29

Cited by 2 publications

(1 citation statement)

References 8 publications

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“…The Ah receptor is an anomaly in that its structure and mechanism is analogous to known steroid receptors; however, no known steroid or endogenous compound is a ligand for the receptor. The Ah receptor is present in the cytosol with the liver and lung containing the highest proportion of receptor in guinea pig, hamster, rat, and mouse (29,89) (Table 3). High levels of receptor exist in thymic tissue of guinea pig and rat.…”

Section: Metabolismmentioning

confidence: 99%

Mechanism of Action of Toxic Halogenated Aromatics

Vickers¹,

Sloop²,

Lucier³

1985

Environmental Health Perspectives

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,3,7, and related halogenated aromatic hydrocarbons are a highly toxic class of environmental contaminants, as evidenced by numerous cases of accidental poisonings of human and animal populations and their extreme toxic potency in laboratory animals. The proposed model for the mechanism of action of TCDD and related compounds is analogous to that of the stereoid hormones, which modulate gene expression through a receptor mechanism. In the steroid receptor model, the compound enters the cell cytoplasm where it acts as a specific ligand, binding selectively to a high affinity receptor protein. Bound to the appropriate ligand, the receptor concentrates in the nucleus where its increased association with chromatin leads to altered gene expression. This model has been useful in characterizing the Ah receptor; however, it does not provide a unifying hypothesis for all biochemical and toxic effects associated with exposure to halogenated aromatic hydrocarbons. Several findings suggest that a primary factor in determining TCDD toxicity might be tissue and species specific factors that control the actions of Ah receptor(s) in target tissues. Furthermore, numerous mechanisms might be involved. Clarifying the mechanism(s) for TCDD toxicity would enhance our ability to predict human health consequences to toxic halogenated aromatic hydrocarbons and would provide a more rational basis for risk analysis.

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Section: Metabolismmentioning

confidence: 99%

Mechanism of Action of Toxic Halogenated Aromatics

Vickers¹,

Sloop²,

Lucier³

1985

Environmental Health Perspectives

View full text Add to dashboard Cite

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Analysis of polychlorinated dibenzofurans, dioxins and related compounds in environmental samples.

Buser¹,

Rappe²,

Bergqvist³

1985

Environ Health Perspect

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The analysis of polychlorinated dibenzofurans (PCDFs), dibenzo-p-dioxins (PCDDs) and to some extent biphenylenes (PCBPs) by high-resolution gas chromatography (HRGC) and mass spectrometry is described. Electron-impact (EI) and negative chemical ionization (NCI) mass spectrometry were used, and their application in environmental analyses documented. NCI shows increased sensitivity to all PCDFs and PCDDs except for 2,3,7,8-and other tetra-CDD isomers. The identification of the various PCDFs and PCDDs, specifically the identification of the toxic and hazardous 2,3,7,8-substituted isomers is emphasized; the unambiguous identification of all 2,3,7,8,-substituted PCDDs is documented. The application of HRGC and mass spectrometry to isomer-specific analyses of samples of aquatic species from the Baltic and the Great Lakes is shown. Results from this and previous studies indicate PCDF and PCDD residues in these organisms including significant levels of 2,3,7,8-substituted isomers. These aquatic species apparently show preferential retention or reduced metabolization rates for these toxic isomers. The results of samples from the Baltic indicate a contamination primarily due to PCDFs. The origin of this contamination seems complex and related to PCBs as well as chlorophenols. PCDF and PCDD isomer distribution patterns from analyses using HRGC and mass spectrometry aid in the identification of origin, sources and elucidation of routes of formation of these compounds. These methods are indispensable in taking measures to reduce future contaminations and to protect our environment.

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Analysis of Polychlorinated Dibenzo-P-Dioxins and Dibenzofurans

Cited by 2 publications

References 8 publications

Mechanism of Action of Toxic Halogenated Aromatics

Mechanism of Action of Toxic Halogenated Aromatics

Analysis of polychlorinated dibenzofurans, dioxins and related compounds in environmental samples.

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