help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
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
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Moreno, M.
Right arrow Articles by Visser, T. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Moreno, M.
Right arrow Articles by Visser, T. J.
Right arrowPubmed/NCBI databases
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*LEVOTHYROXINE
*LIOTHYRONINE

Endocrinology, Vol 135, 1004-1009, Copyright © 1994 by Endocrine Society

ARTICLES

Rapid glucuronidation of tri- and tetraiodothyroacetic acid to ester glucuronides in human liver and to ether glucuronides in rat liver

M Moreno, E Kaptein, F Goglia and TJ Visser
Department of General and Environmental Physiology, University of Naples, Italy.

T3 is the principal bioactive thyroid hormone, although its metabolite 3,3',5-triiodothyroacetic acid (TA3) shows higher affinity for the nuclear T3 receptor. However, TA3 has a low in vivo potency because of its short half-life in both humans and rats. We have compared the glucuronidation of TA3, 3,3',5,5'-tetraiodothyroacetic (TA4), T3, and T4 by human and rat liver microsomes. In rat liver, TA3 and TA4 were glucuronidated about 20 times faster than T3 and T4. Both TA3 and TA4 glucuronides were stable during treatment with dilute base or methanol, suggesting that they represent ether glucuronides with the phenolic hydroxyl group. In human liver, TA3 and TA4 were glucuronidated about 1500 and 200 times faster than T3 and T4, respectively. Both TA3 and TA4 glucuronides were hydrolyzed by treatment for 30 min at 37 C with 0.1 M NaOH and showed transesterification to the methyl esters by treatment with methanol, suggesting that they represent ester glucuronides with the carboxyl group. Therefore, both TA3 and TA4 undergo very rapid, but different, types of glucuronidation in human and rat liver. The high glucuronidation rates may explain their short half-lives and the low bioactivity of TA3 in vivo.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
G. Medina-Gomez, R. M. Calvo, and M.-J. Obregon
Thermogenic effect of triiodothyroacetic acid at low doses in rat adipose tissue without adverse side effects in the thyroid axis
Am J Physiol Endocrinol Metab, April 1, 2008; 294(4): E688 - E697.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
J. Wang, J. L. Falany, and C. N. Falany
Expression and Characterization of a Novel Thyroid Hormone-Sulfating Form of Cytosolic Sulfotransferase from Human Liver
Mol. Pharmacol., February 1, 1998; 53(2): 274 - 282.
[Abstract] [Full Text]

Home page
 J. Biol. Chem.Home page
R. C.J. Ribeiro, R. R. Cavalieri, N. Lomri, C. M. Rahmaoui, J. D. Baxter, and B. F. Scharschmidt
Thyroid Hormone Export Regulates Cellular Hormone Content and Response
J. Biol. Chem., July 19, 1996; 271(29): 17147 - 17151.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1994 by The Endocrine Society