AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 251: E156-E163, 1986;
0193-1849/86 $5.00
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 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 van der Heyden, J. T.
Right arrow Articles by Krenning, E. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van der Heyden, J. T.
Right arrow Articles by Krenning, E. P.

AJP - Endocrinology and Metabolism, Vol 251, Issue 2 156-E163, Copyright © 1986 by American Physiological Society

ARTICLES

Effects of caloric deprivation on thyroid hormone tissue uptake and generation of low-T3 syndrome

J. T. van der Heyden, R. Docter, H. van Toor, J. H. Wilson, G. Hennemann and E. P. Krenning

Changes in thyroid hormone metabolism in the low-3,5,3'-triiodothyronine (T3) syndrome cannot be fully explained in all conditions by a decrease in 5'-deiodinase activity. Recent observations showed that in rat hepatocytes iodothyronines are taken up by an active transport mechanism. To investigate whether regulation, i.e., inhibition of active transmembraneous transport for iodothyronines in humans may contribute to the generation of the low-T3 syndrome, tracer thyroxine (T4) and T3 kinetic studies were performed in 10 obese subjects before and after 7 days on a 240 kcal diet. Kinetics analyses were performed according to a three-pool model of distribution and metabolism for both T4 and T3. For T4 kinetics, during caloric deprivation serum total T4 and plasma pool did not change and production rate and metabolic clearance rate (MCR) were significantly lower. Despite a significantly higher serum free T4, the mass transfer rate to the rapidly equilibrating pool (REP) and the slowly equilibrating pool (SEP) diminished significantly, leading to smaller tissue pools. For T3 kinetics, both serum total T3, free T3, plasma pool, and production rate diminished significantly, while MCR remained unchanged. Mass transfer rates to the REP and the SEP were lowered by approximately 50%, leading to smaller tissue pools. These changes cannot be fully explained by a similar decrease of serum free T3 (only 25%), indicating a diminished transport efficiency for T3. In conclusion, during caloric restriction, transport of T4 and T3 into tissues is diminished, and this phenomenon is much more pronounced for T4 than for T3.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 Am. J. Clin. Nutr.Home page
J. R Gingras, V. Harber, C. J Field, and L. J McCargar
Metabolic assessment of female chronic dieters with either normal or low resting energy expenditures
Am. J. Clinical Nutrition, June 1, 2000; 71(6): 1413 - 1420.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online