Abstract
Hepatic cytosolic glutathione transferase activity with 1-chloro-2,4-dinitrobenzene as substrate was induced by 3-methylcholanthrene or β-naphthoflavone in C57BL/6N inbred mice and in (C57BL/6N)(DBA/2N)F1 but not in DBA/2N inbred mice. High doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin induced the transferase activity in both C57BL/6N and DBA/2N mice. The glutathione transferase activity with benzo[a]pyrene 4,5-oxide as substrate was induced by 3-methylcholanthrene in C57BL/6N but not DBA/2N mice. The transferase activity with styrene 7,8-oxide as substrate was different from either of the above activities in that about twofold induction by 3-methylcholanthrene occurred in both C57BL/6N and DBA/2N mice. Among progeny from the (C57BL/6N)(DBA/2N)F1 x DBA/2N backcross, however, no association was found between the transferase induction process by 3-methylcholanthrene and the presence of the Ah receptor [i.e., inducible aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity]. It is therefore concluded that induction of glutathione transferase activity by polycyclic aromatic compounds is mediated by a gene(s) distinct from the Ah regulatory genes. These data emphasize the importance of examining progeny from the appropriate backcross before making conclusions about the genetic linkage of any two expressed traits.
ACKNOWLEDGMENTS We thank Dr. William H. Habig for valuable discussions concerning the early portions of this work. The valuable technical help of Ms. Nancy M. Jensen and the expert secretarial assistance of Ms. Ingrid E. Jordan are also greatly appreciated.
- Copyright © 1980 by The American Society for Pharmacology and Experimental Therapeutics
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