AJP - Regu Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol (June 20, 2002). doi:10.1152/ajpregu.00015.2002
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
283/5/R1155    most recent
00015.2002v1
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 Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shepherdley, C. A
Right arrow Articles by Darras, V. M
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shepherdley, C. A
Right arrow Articles by Darras, V. M

Articles in PresS, published online ahead of print June 20, 2002
Am J Physiol Regu Physiol, 10.1152/ajpregu.00015.2002
Submitted on January 11, 2002
Accepted on May 17, 2002

Glucocorticoids, thyroid hormones and iodothyronine deiodinases in embryonic saltwater crocodiles

Caroline A Shepherdley1*, Christopher B Daniels2, Sandra Orgeig2, Samantha J Richardson3, Barbara K Evans1, and Veerle M Darras4

1 Department of Zoology, The University of Melbourne, Melbourne, Victoria, Australia
2 Department of Environmental Biology, Adelaide University, Adelaide, South Australia, Australia
3 Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
4 Laboratory of Comparative Endocrinology, Catholic University of Leuven, Leuven, Belgium

* To whom correspondence should be addressed. E-mail: sjrich{at}unimelb.edu.au.

We investigated the relationship between glucocorticoids, thyroid hormones and outer ring and inner ring deiodinases (ORD and IRD) during embryonic development in the saltwater crocodile (Crocodylus porosus). We treated the embryos with the synthetic glucocorticoid dexamethasone (DEX), triiodothyronine (T3) and a combination of these two hormones (DEX + T3). The effects of these treatments were specific in different tissues and at different stages of development, and also brought about changes in plasma concentrations of free thyroid hormones and corticosterone. Administration of DEX to crocodile eggs resulted in a decrease in T4 ORD activities in liver and kidney microsomes, and a decrease in the high-Km rT3 ORD activity in kidney microsomes, on day 60 of incubation. DEX treatment increased the T4 ORD activity in liver microsomes, but not kidney microsomes, on day 75 of incubation. DEX administration decreased T3 IRD activity in liver microsomes; however, this decrease did not change plasma free T3 concentrations, which suggests that free thyroid hormone levels are likely to be tightly regulated during development.




This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
S. J. Richardson, J. A. Monk, C. A. Shepherdley, L. O. E. Ebbesson, F. Sin, D. M. Power, P. B. Frappell, J. Kohrle, and M. B. Renfree
Developmentally regulated thyroid hormone distributor proteins in marsupials, a reptile, and fish
Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2005; 288(5): R1264 - R1272.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
H. A. Blacker, S. Orgeig, and C. B. Daniels
Hypoxic control of the development of the surfactant system in the chicken: evidence for physiological heterokairy
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2004; 287(2): R403 - R410.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
T. J. Cole, N. M. Solomon, R. Van Driel, J. A. Monk, D. Bird, S. J. Richardson, R. J. Dilley, and S. B. Hooper
Altered Epithelial Cell Proportions in the Fetal Lung of Glucocorticoid Receptor Null Mice
Am. J. Respir. Cell Mol. Biol., May 1, 2004; 30(5): 613 - 619.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
L. C. Sullivan, S. Orgeig, and C. B. Daniels
Control of the development of the pulmonary surfactant system in the saltwater crocodile, Crocodylus porosus
Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2002; 283(5): R1164 - R1176.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 2002 by the American Physiological Society.