Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
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 ISI Web of Science
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 (7)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Barhoumi, R.
Right arrow Articles by Burghardt, R. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Barhoumi, R.
Right arrow Articles by Burghardt, R. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Toxicological Sciences 68, 444-450 (2002)
Copyright © 2002 by the Society of Toxicology

MOLECULAR AND GENETIC TOXICOLOGY

Characterization of Calcium Oscillations in Normal and Benzo[a]pyrene-Treated Clone 9 Cells

Rola Barhoumi*,{ddagger}, Youssef Mouneimne{dagger}, Igbal Awooda*, Stephen H. Safe{dagger},{ddagger}, Kirby C. Donnelly*,{ddagger} and Robert C. Burghardt*,{ddagger},1

* Department of Veterinary Anatomy and Public Health, {dagger} Department of Physiology and Pharmacology, and {ddagger} Faculty of Toxicology, Texas A&M University, College Station, Texas 77843

Intracellular Ca2+ oscillations induced by oxytocin and vasopressin were analyzed in a rat liver cell line (Clone 9) in order to identify mechanisms by which benzo[a]pyrene (BaP) alters Ca2+signaling patterns in these cells. Clone 9 cells exhibit an initial Ca2+ spike, followed by Ca2+ oscillations upon oxytocin or vasopressin treatment. The range of frequencies (maximum 110 mHz) was dependent on agonist concentration with a constant amplitude less than or equal to the amount of Ca2+ generated from the inositol trisphosphate (InsP3)-sensitive pool. This study examined contributions of extracellular and intracellular pools to the frequency of Ca2+ oscillations and the role of membrane channels, second messengers, and different pharmacological reagents on the regulation of oscillation frequency in both control and BaP-treated cells. Results indicated that the Ca2+ oscillations are mainly due to inositol 1,4,5-triphosphate (InsP3)-sensitive stores and that extracellular Ca2+ contributes to refilling of this intracellular Ca2+ pool. The frequency of Ca2+ oscillations is also sharply affected by protein kinase C activated by phospholipase C. In BaP-treated Clone 9 cells, basal Ca2+ levels were elevated and the frequency of Ca2+ oscillations was suppressed in a dose-dependent fashion. Suppression of Ca2+ oscillations is due, at least in part, to an effect of BaP on enhanced opening of K+ channels. This was confirmed by showing that inhibition of the K+ channel opening by tetraethylammonium chloride can reverse the effect of BaP on oxytocin-induced Ca2+ oscillations, and potentially decrease the toxicity of BaP.

Key Words: Ca2+ oscillations; oxytocin; vasopressin; fluorescence microscopy; laser cytometry; BaP.


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


This article has been cited by other articles:


Home page
 Toxicol PatholHome page
K. T. Morgan, M. Pino, L. M. Crosby, Min Wang, T. C. Elston, Z. Jayyosi, M. Bonnefoi, and G. Boorman
Complementary Roles for Toxicologic Pathology and Mathematics in Toxicogenomics, With Special Reference to Data Interpretation and Oscillatory Dynamics
Toxicol Pathol, January 1, 2004; 32(1_suppl): 13 - 25.
[Abstract] [PDF]


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.