Record Display for the EPA National Library Catalog


Main Title Differential Hepatotoxicity and Cytochrome P450 Responses of Fischer-344 Rats to the Three Isomers of Dichlorobenzene.
Author Allis, J. W. ; Simmons, J. E. ; House, D. E. ; Robinson, B. L. ; Berman, E. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC. Environmental Toxicology Div.
Publisher c1992
Year Published 1992
Report Number EPA/600/J-93/102;
Stock Number PB93-175719
Additional Subjects Cytochrome P-450 ; Liver ; Toxicity ; Dose-response relationships ; Rats ; Isomers ; Alanine aminotransferase ; Aspartate aminotransferase ; Substrate specificity ; Necrosis ; Reprints ; Dichlorobenzenes
Library Call Number Additional Info Location Last
NTIS  PB93-175719 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
The acute hepatotoxicity and response of hepatic cytochrome P450 to treatment with the three isomers of dichlorobenzene (DCB) have been investigated. The objectives were to estimate the onset of toxicity and to further elucidate the role of cytochrome P450 in the metabolism and toxicity of these compounds. In a study design employing one animal per dose level, Fischer-344 rats were gavaged with up to 25 different dosages, then evaluated 24 h later. Hepatic necrosis, serum alanine aminotransferase, and serum aspartate aminotransferase exhibited similar patterns demonstrating that ortho-DCB (o-DCB) was the most toxic in terms of both earliest onset and degree of response at higher dosages. For these three endpoints, meta-DCB (m-DCB) exhibited a lesser toxicity. Para-DCB (p-DCB) did not cause changes in these three endpoints, but hepatic degenerative changes were found. Total hepatic cytochrome P450 responses were also different after treatment with each isomer. The o-DCB produced a dose-dependent decrease in P450 beginning at dosages lower than the onset of necrosis and appeared to be a suicide substrate for P450. The m-DCB treatment increased P450 at dosages below the onset of necrosis and decreased P450 at higher dosages, with the decline preceding the onset of hepatocyte death. (Copyright (c) 1992 VCH Publishers, Inc.)