Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (29)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Franzén, B.
Right arrow Articles by Toftgård, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Franzén, B.
Right arrow Articles by Toftgård, R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1988 Oxford University Press

research-article

TCDD receptor ligands present in extracts of urban air particulate matter induce aryl hydrocarbon hydroxylase activity and cytochrome P-450c gene expression in rat hepatoma cells

Bo Franzén, Tapio Haaparanta, Jan-Åke Gustafsson and Rune Toftgård 1 2

Department of Medical Nutrition, Karolinska Institute, Huddinge University Hospital F69, S-14l 86 Huddinge
1Center for Biotechnology, Karolinska Institute, Huddinge University Hospital F82, S-141 86 Huddinge, Sweden

22 whom reprint requests should be sent

In previous studies we have shown that substances associated with particulates collected from urban air and automobile exhaust bind with high affinity to the 2,3,7,8-tetrachlorodi-benzo-p-dioxin (TCDD) receptor present in rat liver cytosol. In this study we used a rat hepatoma cell line, H4IIE, to investigate the effect of such substances on an enzyme system, aryl hydrocarbon hydroxylase (AHH), which is regulated via the TCDD receptor. The results demonstrate that AHH activity in the H4IIE cell line can be induced by extracts of particulates collected from urban air and automobile exhausts in a dose-dependent manner, and that the AHH activity is inducible by five polycycic aromatic hydrocarbons (PAHs) including 1-/3-nitrobenzo[a]pyrene and 6-chlorochrysene, all present in extracts of particulates from urban air and automobile exhausts. The induction of AHH activity is correlated to apparent TCDD receptor affinity for investigated PAHs (r = 0.85) and particulate extracts. Biochemically, treatment of the cells with 5,6-benzoflavone significantly increased the level of cytochrome P-450c but not P-450d as shown by Immunoblotting and analysis of mRNA levels. The data indicate that substances present in extracts of urban air particulates can interact with the TCDD receptor in intact cells and cause an accumulation of cytochrome P-450c mRNA leading to an increased synthesis of the gene product and thus an increase in enzyme activity.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.