Page 839 - The Toxicology of Fishes

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Reproductive Impairment of Great Lakes

Lake Trout by Dioxin-Like Chemicals

Donald E. Tillitt, Philip M. Cook, John P. Giesy,
Warren Heideman, and Richard E. Peterson

CONTENTS
Introduction............................................................................................................................................820
Historical Aspects of the Great Lakes Lake Trout Fishery ..................................................................822
Chemical Contamination of the Great Lakes and Lake Trout..............................................................824
Aryl-Hydrocarbon-Receptor-Mediated Toxicity in Fish.......................................................................826
Presence of AhR and ARNT in Fish and the AhR Signaling Pathway......................................827
Functional Mechanisms of Dioxin Toxicity Are Revealed in Fish.............................................827
AhR Signaling in Fish .................................................................................................................828
Endpoints of TCDD Developmental Toxicity in Fish.................................................................829
Edema .................................................................................................................................829
Cardiovascular Toxicity......................................................................................................830
Anemia................................................................................................................................830
Impaired Chondrogenesis...................................................................................................830
Neurotoxicity ......................................................................................................................831
Female Reproductive Toxicity of TCDD in Fish ........................................................................831
ZfAHR2 Is Required for TCDD Developmental Toxicity in Zebrafish............................ 832
ZfARNT1 but Not ZfARNT2 Is Required for
TCDD Developmental Toxicity in Zebrafish................................................................832
Why Is Understanding AhR Signaling in Zebrafish Important?.................................................833
Induction of CYP1A Is Not Required for TCDD Developmental Toxicity in Zebrafish.....833
Is TCDD Developmental Toxicity Dependent on AhRE Binding?...................................834
Structure–Activity Relationships for PCB, PCDD, and PCDF Congeners as AhR Agonists ............. 835
TCDD Toxicity Equivalency Factor Approach............................................................................835
Ecological Risk Assessment with Fish-Specific TEFs..........................................................................837
Early-Life-Stage Toxicity of PCBs in Trout................................................................................838
Additive, Synergistic, or Antagonistic Interactions of Congener Pairs ......................................838
Toxicity of Mixture of PCBs, PCDDs, and PCDFs Toward Trout Early Life Stages ............... 839
Symptoms of TCDD-Induced Early-Life-Stage Toxicity in Salmonines.............................................840
Time Course .................................................................................................................................840
Pathologic Alterations ..................................................................................................................841
Impaired Swim Bladder Inflation.......................................................................................842
Impaired Cardiovascular Function .....................................................................................842
Species Differences in TCDD Toxic Potency.......................................................................................843
Developmental Stages Sensitive to TCDD Toxicity....................................................................844
Route of TCDD Egg Exposure and Sensitivity to Toxicity........................................................844
Field Observations of Exposures and Effects in Great Lakes Salmonines..........................................845
Correlations of Contaminants with Reproductive Success in Great Lakes Salmonines ............ 845
Field Observations of Dioxin-Like Pathologies in Great Lakes Salmonines............................. 846

819