The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight
Joint Authors
Ebling, Francis J. P.
Murphy, Michelle
Source
Issue
Vol. 2011, Issue 2011 (31 Dec. 2011), pp.1-7, 7 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2011-06-22
Country of Publication
Egypt
No. of Pages
7
Main Subjects
Abstract EN
Seasonal cycles of body weight provide a natural model system to understand the central control of energy balance.
Studies of such cycles in Siberian hamsters suggest that a change in the hypothalamic availability of thyroid hormone is the key determinant of annual weight regulation.
Uptake of thyroid hormone into the hypothalamus from the peripheral circulation occurs largely through a specific monocarboxylate transporter expressed by tanycyte cells lining the third ventricle.
Tanycytes are the principal brain cell type expressing type II and type III deiodinases, so they control the local concentrations of T4, T3, and inactive metabolites.
Type III deiodinase mRNA in tanycytes is photoperiodically upregulated in short photoperiod.
This would be expected to reduce the availability of T3 in the hypothalamus by promoting the production of inactive metabolites such as rT3.
Experimental microimplantation of T3 directly into the hypothalamus during short-days promotes a long-day phenotype by increasing food intake and body weight without affecting the peripheral thyroid axis.
Thus, thyroid hormone exerts anabolic actions within the brain that play a key role in the seasonal regulation of body weight.
Understanding the precise actions of thyroid hormone in the brain may identify novel targets for long-term pharmacological manipulation of body weight.
American Psychological Association (APA)
Murphy, Michelle& Ebling, Francis J. P.. 2011. The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight. Journal of Thyroid Research،Vol. 2011, no. 2011, pp.1-7.
https://search.emarefa.net/detail/BIM-468152
Modern Language Association (MLA)
Murphy, Michelle& Ebling, Francis J. P.. The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight. Journal of Thyroid Research No. 2011 (2011), pp.1-7.
https://search.emarefa.net/detail/BIM-468152
American Medical Association (AMA)
Murphy, Michelle& Ebling, Francis J. P.. The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight. Journal of Thyroid Research. 2011. Vol. 2011, no. 2011, pp.1-7.
https://search.emarefa.net/detail/BIM-468152
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-468152