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Expression of hepatic pyruvate carboxylase mRNA in C57BL/6J Ah(b/b) and congenic Ah((d/d)) mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.
- Source :
-
Journal of biochemical toxicology [J Biochem Toxicol] 1996; Vol. 11 (1), pp. 51-6. - Publication Year :
- 1996
-
Abstract
- The activity and level of hepatic pyruvate carboxylase (PC) has been reported to be altered by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in mice. If alteration in PC level/activity by TCDD influences TCDD toxicity, one would expect to observe an early post-exposure reduction in PC mRNA. To examine the molecular events responsible for the alteration of PC activity in livers of TCDD-treated mice, we designed a synthetic DNA oligonucleotide probe specific for PC mRNA. Northern blot analysis on RNA extracts from hepatic tissue at various times and doses post-TCDD exposure were done. Furthermore, to elucidate the role of the dioxin Ah locus on alterations of PC activity by TCDD, we utilized C57BL/6J (Ahb/b, Ah high TCDD affinity) mice and a congenic (Ahd/d, AH low TCDD affinity) mouse strain. At 8 days post TCDD treatment, a dose-dependent reduction of hepatic PC mRNA levels was observed in Ahb/b mice. The response, reduction in PC mRNA levels, in the Ahb/b strain was about 10-fold greater than that of comparably exposed congenic Ahd/d mice. These results indicate that previously reported reductions in PC activity/level by TCDD treatment of mice is a consequence of a reduction in PC mRNA levels and that the effect requires a competent Ah receptor.
- Subjects :
- Animals
Binding, Competitive
Blotting, Northern
Dose-Response Relationship, Drug
Gene Expression Regulation, Enzymologic genetics
Liver cytology
Liver enzymology
Male
Mice
Mice, Inbred C57BL
Mice, Inbred Strains
Oligonucleotide Probes
Pyruvate Carboxylase biosynthesis
Receptors, Aryl Hydrocarbon drug effects
Receptors, Aryl Hydrocarbon metabolism
Species Specificity
Gene Expression Regulation, Enzymologic drug effects
Liver drug effects
Polychlorinated Dibenzodioxins toxicity
Pyruvate Carboxylase genetics
RNA, Messenger biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 0887-2082
- Volume :
- 11
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of biochemical toxicology
- Publication Type :
- Academic Journal
- Accession number :
- 8806052
- Full Text :
- https://doi.org/10.1002/(SICI)1522-7146(1996)11:1<51::AID-JBT7>3.0.CO;2-U