This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sánchez, E. Articles by Lechan, R. M. Search for Related Content PubMed PubMed Citation Articles by Sánchez, E. Articles by Lechan, R. M. Pubmed/NCBI databases Gene GEO Profiles HomoloGene Protein UniGene Compound via MeSH Substance via MeSH

Induction of Type 2 Iodothyronine Deiodinase in the Mediobasal Hypothalamus by Bacterial Lipopolysaccharide: Role of Corticosterone

Tupper Research Institute and Department of Medicine (E.S., P.S.S., C.F., R.M.L.), Division of Endocrinology, Diabetes, and Metabolism, Tufts-New England Medical Center, and Department of Neuroscience (R.M.L.), Tufts University School of Medicine, Boston, Massachusetts 02111; and Department of Endocrine Neurobiology (C.F.), Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest H-1083, Hungary

Address all correspondence and requests for reprints to: Ronald M. Lechan, M.D., Ph.D., Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Tufts-New England Medical Center, Box No. 268, 750 Washington Street, Boston, Massachusetts 02111. E-mail: rlechan{at}tufts-nemc.org.

To determine whether endotoxin-induced activation of type 2 iodothyronine deiodinase (D2) in the mediobasal hypothalamus is dependent on circulating levels of corticosterone, the effect of bacterial lipopolysaccharide (LPS) on D2 gene expression was studied in adrenalectomized, corticosterone-clamped adult, male, Sprague Dawley rats. In sham-adrenalectomized animals, LPS (250 µg/100 g body weight) increased circulating levels of corticosterone and IL-6, as well as tanycyte D2 mRNA in the mediobasal hypothalamus. Adrenalectomized, corticosterone-clamped animals showed no significant rise in corticosterone after LPS, compared with saline-treated controls but increased IL-6 levels and tanycyte D2 mRNA similar to LPS-treated sham controls. To further clarify the potential role of corticosterone in the regulation of D2 gene expression by LPS, animals were administered high doses of corticosterone to attain levels similar to that observed in the LPS-treated group. No significant increase in D2 mRNA was observed in the mediobasal hypothalamus with the exception of a small subpopulation of cells in the lateral walls of the third ventricle. These data indicate that the LPS-induced increase in D2 mRNA in the mediobasal hypothalamus is largely independent of circulating corticosterone and indicate that mechanisms other than adrenal activation are involved in the regulation of most tanycyte D2-expressing cells by endotoxin.

This article has been cited by other articles:

				K. R. Vella and A. N. Hollenberg The Ups and Downs of Thyrotropin-Releasing Hormone Endocrinology, May 1, 2009; 150(5): 2021 - 2023. [Full Text] [PDF]

				E. Sanchez, M. A. Vargas, P. S. Singru, I. Pascual, F. Romero, C. Fekete, J.-L. Charli, and R. M. Lechan Tanycyte Pyroglutamyl Peptidase II Contributes to Regulation of the Hypothalamic-Pituitary-Thyroid Axis through Glial-Axonal Associations in the Median Eminence Endocrinology, May 1, 2009; 150(5): 2283 - 2291. [Abstract] [Full Text] [PDF]