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RECORD NUMBER: 3 OF 3

OLS Field Name OLS Field Data
Main Title Tetrachorobiphenyl Metabolism, Toxicity, and Regulation of Cytochrome P45O Expression in a Marine Teleost Fish.
Author White, R. D. ;
CORP Author Massachusetts Inst. of Tech., Cambridge.
Publisher Feb 95
Year Published 1995
Report Number MIT/WHOI-95-07; PHS-P30ES02109 ;EPA-R817988;
Stock Number AD-A305 892/2
Additional Subjects Toxicity ; In vitro analysis ; In vivo analysis ; Ribonucleic acids ; Hepatitis ; Fishes ; Carbon tetrachloride ; Epithelium ; Jobs ; Tail assemblies ; Enzymes ; Proteins ; Intensity ; Reactivities ; Metabolism ; Deoxyribonucleic acids ; Oxygen ; Dosage ; Cells(Biology) ; Fins ; Induction systems ; Lesions ; Spleen ; Microsomes ; Organs(Anatomy) ; Oceanography ; Cetacea ; Endothelium ;
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NTIS  AD-A305 892/2 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 08/15/1996
Collation 232p
Abstract
The effects of 3,3',4,4'-Tetrachlorobiphenyl (TCB) were examined in scup (Stenotomus chrysops). A low TCB dose elicited strong induction of hepatic CYPlAl mRNA, protein, and activity. A high TCB dose elicited strong induction of hepatic CYPlAl mRNA, but not of CYPlAl protein or activity. This 'suppression' at the high dose was specific for CYPlAl, and was not seen for other enzymes. In vitro studies indicate that hepatic CYPlAl is inactivated in the presence of TCB plus cofactor, likely due to the production of reactive oxygen species during TCB occupation of the active site. CYPlAl inactivation by TCB in vitro may explain suppression of CYPlAl protein content in vivo. TCB induced CYPlAl content in endothelial and epithelial cells of several organs. Intensity of induction was time-dependent, dose-dependent, and varied among the different organs. TCB treatment caused lesions or cellular alterations in liver, kidney, gill, spleen, and tail fin. 3,3',4,4'-TCB and 2,2',5,5'-TCB were both metabolized by hepatic microsomes from scup, beluga whale, and pilot whale. Studies indicate that 3,3',4,4'-TCB is metabolized by scup CYPlAl and 2,2',5,5'-TCB by the putative scup CYP2B. Studies suggest that 3,3',4,4'-TCB is metabolized by cetacean CYPlA, and that both cetacean species express a possible CYP2B enzyme in liver.