Skip Navigation



ToxSci Advance Access published online on December 14, 2006
Toxicological Sciences, doi:10.1093/toxsci/kfl185
This Article
Right arrow Advance Access manuscript (PDF) Freely available
Right arrow All Versions of this Article:
96/1/145    most recent
kfl185v1
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 arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Quinn, A. L.
Right arrow Articles by Plotzke, K. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Quinn, A. L.
Right arrow Articles by Plotzke, K. P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

In vitro and In vivo Evaluation of the Estrogenic, Androgenic and Progestagenic Potential of Two Cyclic Siloxanes

Anne L. Quinn1, Jane M. Regan, Joseph M. Tobin, Brian J. Marinik, Joan M. McMahon, Debra A. McNett, Christopher J. Sushynski, Steven D. Crofoot, Paul A. Jean and Kathleen P. Plotzke

Dow Corning Corporation, Midland, Michigan 48686

1 Address correspondence to: Anne L. Quinn, Ph.D., Dow Corning Corporation, 2200 West Salzburg Road, Mail Stop: CO3101, Midland, Michigan 48686-0994, Fax: (989) 496-5595, E-mail: Anne.Quinn{at}dowcorning.com

Received September 13, 2006; accepted November 21, 2006


  Abstract

The purpose of these experiments was to determine the potential estrogenic, androgenic and progestagenic activity of two cyclic siloxanes, octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). Receptor binding experiments and a luciferase reporter gene assay were used to determine if the materials were able to bind and activate either the estrogen receptors (ER) or progesterone receptors (PR) -alpha or beta. The rat uterotrophic assay (RUA) for estrogenic activity and the Hershberger assay for androgenic activity were utilized as the in vivo assays. For the estrogen receptor binding studies, D4 was shown to bind to ER-alpha but not to ER-beta. D5 did not bind to either of the two receptors. D4 activated the reporter gene at 10µM while D5 was considered negative in the estrogen reporter gene assay. Neither material was a ligand for the progesterone receptors. Both the RUA and Hershberger assays were conducted using whole body inhalation of the two materials for 16 hours/day. D4 resulted in a small, but significant increase in both wet and blotted uterine weight as well as increases in both luminal and glandular epithelial cell height in both Sprague Dawley and Fischer 344 rats. D5 was negative in both rat strains, indicating that D5 does not possess estrogenic activity. Neither material possessed any significant anti-estrogenic activity. Both materials were negative in the Hershberger assay indicating that neither material possesses any significant androgenic activity. Our studies have shown that D4 exhibits a low affinity for estrogen receptor-alpha in vitro and a weakly estrogenic response in vivo.

Key Words: D4; D5; octamethylcyclotetrasiloxane; decamethylcyclopentasiloxane; silicone; siloxane; estrogen receptor alpha and beta; androgen; progesterone; luciferase reporter gene; RUA; estrogenic.


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 SciHome page
M. B. Reddy, I. D. Dobrev, D. A. McNett, J. M. Tobin, M. J. Utell, P. E. Morrow, J. Y. Domoradzki, K. P. Plotzke, and M. E. Andersen
Inhalation Dosimetry Modeling with Decamethylcyclopentasiloxane in Rats and Humans
Toxicol. Sci., October 1, 2008; 105(2): 275 - 285.
[Abstract] [Full Text] [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.