Journal article
Distribution and macromolecular binding of benzo[a]pyrene and two polychlorinated biphenyl congeners in female mice
Chemico-biological interactions, Vol.137(3), pp.243-258
2001
DOI: 10.1016/S0009-2797(01)00256-3
PMID: 11566292
Abstract
PCBs are complete rodent carcinogens and their potent tumor promoting activity has been reported, but their tumor-initiating activity remains controversial. Macromolecular binding of PCB metabolites has been demonstrated in vitro, but this issue remains unclear in vivo. The purpose of this study was to determine the binding affinity of 4-chlorobiphenyl and 3,3′,4,4′-tetrachlorobiphenyl to proteins and DNA in vivo. C57/BL6 female mice were treated intraperitoneally with hepatic enzyme inducers (phenobarbital and β-naphthoflavone) and then with
14C-labelled polychlorinated biphenyls or benzo[a]pyrene. The short-term distribution of labeled compounds into liver, lungs and kidneys and into different sub-cellular fractions of these tissues was assessed and the DNA and proteins from the 700×
g pellet were further purified to assess covalent binding. All compounds were distributed in low amounts into the liver, kidneys and lungs, with the greatest accumulation in the liver, and the lowest in lungs. In all tissues, test compounds were mostly found in cytosols and organellar pellets (10,000×
g), and lower amounts were present in nuclear pellets (700×
g) and microsomes. In lungs and kidneys, only benzo[a]pyrene showed significant covalent binding to proteins. In the liver, protein binding indices were significant for all compounds (
P<0.05), but no significant binding of the test compounds to DNA could be demonstrated with this approach. Our results suggest that at the 24 h time point, all compounds were activated to electrophilic intermediates prone to macromolecular binding. Hepatic proteins apparently act as a sink for PCB-derived electrophiles, thus preventing detectable levels of covalent binding to hepatic DNA or to proteins in less metabolically active tissues.
Details
- Title: Subtitle
- Distribution and macromolecular binding of benzo[a]pyrene and two polychlorinated biphenyl congeners in female mice
- Creators
- Daria Pereg - Graduate Center for Toxicology, 306 Health Sciences Research Building, University of Kentucky Medical Center, Lexington, KY 40536-0305, USANilufer Tampal - Graduate Center for Toxicology, 306 Health Sciences Research Building, University of Kentucky Medical Center, Lexington, KY 40536-0305, USAParvaneh Espandiari - Graduate Center for Toxicology, 306 Health Sciences Research Building, University of Kentucky Medical Center, Lexington, KY 40536-0305, USALarry W Robertson - Graduate Center for Toxicology, 306 Health Sciences Research Building, University of Kentucky Medical Center, Lexington, KY 40536-0305, USA
- Resource Type
- Journal article
- Publication Details
- Chemico-biological interactions, Vol.137(3), pp.243-258
- Publisher
- Elsevier Ireland Ltd
- DOI
- 10.1016/S0009-2797(01)00256-3
- PMID
- 11566292
- ISSN
- 0009-2797
- eISSN
- 1872-7786
- Language
- English
- Date published
- 2001
- Academic Unit
- Occupational and Environmental Health
- Record Identifier
- 9984002428502771
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