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Sample records for regulates thyroid hormone

  1. Regulation of Thyroid Hormone Bioactivity in Health and Disease

    NARCIS (Netherlands)

    R.P. Peeters (Robin)

    2005-01-01

    textabstractTThyroid hormone plays an essential role in a variety of metabolic processes in the human body. Examples are the effects of thyroid hormone on metabolism and on the heart. The production of thyroid hormone by the thyroid is regulated by thyroid stimulating hormone (TSH) via the TSH

  2. Tissue specific regulation of lipogenesis by thyroid hormone

    Energy Technology Data Exchange (ETDEWEB)

    Blennemann, B.; Freake, H. (Univ. of Connecticut, Storrs (United States))

    1990-02-26

    Thyroid hormone stimulates long chain fatty acid synthesis in rat liver by increasing the amounts of key lipogenic enzymes. Sparse and conflicting data exist concerning its action on this pathway in other tissues. The authors recently showed that, in contrast to liver, hypothyroidism stimulates lipogenesis in brown adipose tissue and have now systematically examined the effects of thyroid state on fatty acid synthesis in other rat tissues. Lipogenesis was assessed by tritiated water incorporation. Euthyroid hepatic fatty acid synthesis (16.6um H/g/h) was reduced to 30% in hypothyroid rats and increased 3 fold in hyperthyroidism. Lipogenesis was detected in euthyroid kidney and heart and these levels were also stimulated by thyroid hormone treatment. Brown adipose tissue was unique in showing increased lipogenesis in the hypothyroid state. Hyperthyroid levels were not different from euthyroid. Effects in white adipose tissue were small and inconsistent. Brain, skin and lung were all lipogenically active, but did not respond to changes in thyroid state. Low but detectable levels of fatty acid synthesis were measured in muscle, which also were non-responsive. A wide spectrum of responses to thyroid hormone are seen in different rat tissues and thus the pathway of long chain fatty acid synthesis would appear to be an excellent model for examining the tissue specific regulation of gene expression by thyroid hormone.

  3. Tissue specific regulation of lipogenesis by thyroid hormone

    International Nuclear Information System (INIS)

    Blennemann, B.; Freake, H.

    1990-01-01

    Thyroid hormone stimulates long chain fatty acid synthesis in rat liver by increasing the amounts of key lipogenic enzymes. Sparse and conflicting data exist concerning its action on this pathway in other tissues. The authors recently showed that, in contrast to liver, hypothyroidism stimulates lipogenesis in brown adipose tissue and have now systematically examined the effects of thyroid state on fatty acid synthesis in other rat tissues. Lipogenesis was assessed by tritiated water incorporation. Euthyroid hepatic fatty acid synthesis (16.6um H/g/h) was reduced to 30% in hypothyroid rats and increased 3 fold in hyperthyroidism. Lipogenesis was detected in euthyroid kidney and heart and these levels were also stimulated by thyroid hormone treatment. Brown adipose tissue was unique in showing increased lipogenesis in the hypothyroid state. Hyperthyroid levels were not different from euthyroid. Effects in white adipose tissue were small and inconsistent. Brain, skin and lung were all lipogenically active, but did not respond to changes in thyroid state. Low but detectable levels of fatty acid synthesis were measured in muscle, which also were non-responsive. A wide spectrum of responses to thyroid hormone are seen in different rat tissues and thus the pathway of long chain fatty acid synthesis would appear to be an excellent model for examining the tissue specific regulation of gene expression by thyroid hormone

  4. Direct Regulation of Mitochondrial RNA Synthesis by Thyroid Hormone

    Science.gov (United States)

    Enríquez, José A.; Fernández-Silva, Patricio; Garrido-Pérez, Nuria; López-Pérez, Manuel J.; Pérez-Martos, Acisclo; Montoya, Julio

    1999-01-01

    We have analyzed the influence of in vivo treatment and in vitro addition of thyroid hormone on in organello mitochondrial DNA (mtDNA) transcription and, in parallel, on the in organello footprinting patterns at the mtDNA regions involved in the regulation of transcription. We found that thyroid hormone modulates mitochondrial RNA levels and the mRNA/rRNA ratio by influencing the transcriptional rate. In addition, we found conspicuous differences between the mtDNA dimethyl sulfate footprinting patterns of mitochondria derived from euthyroid and hypothyroid rats at the transcription initiation sites but not at the mitochondrial transcription termination factor (mTERF) binding region. Furthermore, direct addition of thyroid hormone to the incubation medium of mitochondria isolated from hypothyroid rats restored the mRNA/rRNA ratio found in euthyroid rats as well as the mtDNA footprinting patterns at the transcription initiation area. Therefore, we conclude that the regulatory effect of thyroid hormone on mitochondrial transcription is partially exerted by a direct influence of the hormone on the mitochondrial transcription machinery. Particularly, the influence on the mRNA/rRNA ratio is achieved by selective modulation of the alternative H-strand transcription initiation sites and does not require the previous activation of nuclear genes. These results provide the first functional demonstration that regulatory signals, such as thyroid hormone, that modify the expression of nuclear genes can also act as primary signals for the transcriptional apparatus of mitochondria. PMID:9858589

  5. Thyroid hormone is required for hypothalamic neurons regulating cardiovascular functions

    NARCIS (Netherlands)

    Mittag, J.; Lyons, D.J.; Sällström, J.; Vujoviv, M.; Dudazy-Gralla, S.; Warner, A.; Wallis, K.; Alkemade, A.; Nordström, K.; Monyer, H.; Broberger, C.; Arner, A.; Vennström, B.

    2013-01-01

    Thyroid hormone is well known for its profound direct effects on cardiovascular function and metabolism. Recent evidence, however, suggests that the hormone also regulates these systems indirectly through the central nervous system. While some of the molecular mechanisms underlying the hormone’s

  6. Thyroid Hormone Regulates the Expression of the Sonic Hedgehog Signaling Pathway in the Embryonic and Adult Mammalian Brain

    OpenAIRE

    Desouza, Lynette A.; Sathanoori, Malini; Kapoor, Richa; Rajadhyaksha, Neha; Gonzalez, Luis E.; Kottmann, Andreas H.; Tole, Shubha; Vaidya, Vidita A.

    2011-01-01

    Thyroid hormone is important for development and plasticity in the immature and adult mammalian brain. Several thyroid hormone-responsive genes are regulated during specific developmental time windows, with relatively few influenced across the lifespan. We provide novel evidence that thyroid hormone regulates expression of the key developmental morphogen sonic hedgehog (Shh), and its coreceptors patched (Ptc) and smoothened (Smo), in the early embryonic and adult forebrain. Maternal hypo- and...

  7. Role and Mechanisms of Actions of Thyroid Hormone on the Skeletal Development

    OpenAIRE

    Kim, Ha-Young; Mohan, Subburaman

    2013-01-01

    The importance of the thyroid hormone axis in the regulation of skeletal growth and maintenance has been well established from clinical studies involving patients with mutations in proteins that regulate synthesis and/or actions of thyroid hormone. Data from genetic mouse models involving disruption and overexpression of components of the thyroid hormone axis also provide direct support for a key role for thyroid hormone in the regulation of bone metabolism. Thyroid hormone regulates prolifer...

  8. The thyroid nodule. Thyrotropin and peripheral thyroid hormones

    International Nuclear Information System (INIS)

    Zimny, M.

    2008-01-01

    Thyrotropin, free triodothyronine and thyroxine represent the standard serological parameters for the diagnostic work-up of the thyroid but only a minority of thyroid nodules present with subclinical or overt thyroid disorders. Besides a review of the regulation and principle of function of thyroid hormones as well as the effects of subclinical or overt hyperthyroidism, the significant role of these parameters beyond the assessment of hyperthyroidism in thyroid nodules is discussed. There is evidence that the level of thyrotropin within the normal range is predictive for the relevance of autonomous functioning nodules and the risk of malignancy of non-functioning thyroid nodules. Furthermore, the ratio of triodothyronine and thyroxine indicates the etiology of hyperthyroidism. Thyrotropin represents the main parameter to determine the adequate dose of thyroid hormone therapy of thyroid nodules. (orig.)

  9. Thyroid Hormone, Cancer, and Apoptosis.

    Science.gov (United States)

    Lin, Hung-Yun; Chin, Yu-Tan; Yang, Yu-Chen S H; Lai, Husan-Yu; Wang-Peng, Jacqueline; Liu, Leory F; Tang, Heng-Yuan; Davis, Paul J

    2016-06-13

    Thyroid hormones play important roles in regulating normal metabolism, development, and growth. They also stimulate cancer cell proliferation. Their metabolic and developmental effects and growth effects in normal tissues are mediated primarily by nuclear hormone receptors. A cell surface receptor for the hormone on integrin [alpha]vβ3 is the initiation site for effects on tumor cells. Clinical hypothyroidism may retard cancer growth, and hyperthyroidism was recently linked to the prevalence of certain cancers. Local levels of thyroid hormones are controlled through activation and deactivation of iodothyronine deiodinases in different organs. The relative activities of different deiodinases that exist in tissues or organs also affect the progression and development of specific types of cancers. In this review, the effects of thyroid hormone on signaling pathways in breast, brain, liver, thyroid, and colon cancers are discussed. The importance of nuclear thyroid hormone receptor isoforms and of the hormone receptor on the extracellular domain of integrin [alpha]vβ3 as potential cancer risk factors and therapeutic targets are addressed. We analyze the intracellular signaling pathways activated by thyroid hormones in cancer progression in hyperthyroidism or at physiological concentrations in the euthyroid state. Determining how to utilize the deaminated thyroid hormone analog (tetrac), and its nanoparticulate derivative to reduce risks of cancer progression, enhance therapeutic outcomes, and prevent cancer recurrence is also deliberated. © 2016 American Physiological Society. Compr Physiol 6:1221-1237, 2016. Copyright © 2016 John Wiley & Sons, Inc.

  10. Thyroid Hormones Are Transport Substrates and Transcriptional Regulators of Organic Anion Transporting Polypeptide 2B1.

    Science.gov (United States)

    Meyer Zu Schwabedissen, Henriette E; Ferreira, Celio; Schaefer, Anima M; Oufir, Mouhssin; Seibert, Isabell; Hamburger, Matthias; Tirona, Rommel G

    2018-07-01

    Levothyroxine replacement therapy forms the cornerstone of hypothyroidism management. Variability in levothyroxine oral absorption may contribute to the well-recognized large interpatient differences in required dose. Moreover, levothyroxine-drug pharmacokinetic interactions are thought to be caused by altered oral bioavailability. Interestingly, little is known regarding the mechanisms contributing to levothyroxine absorption in the gastrointestinal tract. Here, we aimed to determine whether the intestinal drug uptake transporter organic anion transporting polypeptide 2B1 (OATP2B1) may be involved in facilitating intestinal absorption of thyroid hormones. We also explored whether thyroid hormones regulate OATP2B1 gene expression. In cultured Madin-Darby Canine Kidney II/OATP2B1 cells and in OATP2B1-transfected Caco-2 cells, thyroid hormones were found to inhibit OATP2B1-mediated uptake of estrone-3-sulfate. Competitive counter-flow experiments evaluating the influence on the cellular accumulation of estrone-3-sulfate in the steady state indicated that thyroid hormones were substrates of OATP2B1. Additional evidence that thyroid hormones were OATP2B1 substrates was provided by OATP2B1-dependent stimulation of thyroid hormone receptor activation in cell-based reporter assays. Bidirectional transport studies in intestinal Caco-2 cells showed net absorptive flux of thyroid hormones, which was attenuated by the presence of the OATP2B1 inhibitor, atorvastatin. In intestinal Caco-2 and LS180 cells, but not in liver Huh-7 or HepG2 cells, OATP2B1 expression was induced by treatment with thyroid hormones. Reporter gene assays revealed thyroid hormone receptor α -mediated transactivation of the SLCO2B1 1b and the SLCO2B1 1e promoters. We conclude that thyroid hormones are substrates and transcriptional regulators of OATP2B1. These insights provide a potential mechanistic basis for oral levothyroxine dose variability and drug interactions. Copyright © 2018 by The American

  11. The thyroid nodule. Thyrotropin and peripheral thyroid hormones; Der Schilddruesenknoten. TSH und periphere Hormone

    Energy Technology Data Exchange (ETDEWEB)

    Zimny, M. [Klinikum Hanau (Germany). Inst. fuer Nuklearmedizin

    2008-09-15

    Thyrotropin, free triodothyronine and thyroxine represent the standard serological parameters for the diagnostic work-up of the thyroid but only a minority of thyroid nodules present with subclinical or overt thyroid disorders. Besides a review of the regulation and principle of function of thyroid hormones as well as the effects of subclinical or overt hyperthyroidism, the significant role of these parameters beyond the assessment of hyperthyroidism in thyroid nodules is discussed. There is evidence that the level of thyrotropin within the normal range is predictive for the relevance of autonomous functioning nodules and the risk of malignancy of non-functioning thyroid nodules. Furthermore, the ratio of triodothyronine and thyroxine indicates the etiology of hyperthyroidism. Thyrotropin represents the main parameter to determine the adequate dose of thyroid hormone therapy of thyroid nodules. (orig.)

  12. Thyroid hormone regulates the expression of the sonic hedgehog signaling pathway in the embryonic and adult Mammalian brain.

    Science.gov (United States)

    Desouza, Lynette A; Sathanoori, Malini; Kapoor, Richa; Rajadhyaksha, Neha; Gonzalez, Luis E; Kottmann, Andreas H; Tole, Shubha; Vaidya, Vidita A

    2011-05-01

    Thyroid hormone is important for development and plasticity in the immature and adult mammalian brain. Several thyroid hormone-responsive genes are regulated during specific developmental time windows, with relatively few influenced across the lifespan. We provide novel evidence that thyroid hormone regulates expression of the key developmental morphogen sonic hedgehog (Shh), and its coreceptors patched (Ptc) and smoothened (Smo), in the early embryonic and adult forebrain. Maternal hypo- and hyperthyroidism bidirectionally influenced Shh mRNA in embryonic forebrain signaling centers at stages before fetal thyroid hormone synthesis. Further, Smo and Ptc expression were significantly decreased in the forebrain of embryos derived from hypothyroid dams. Adult-onset thyroid hormone perturbations also regulated expression of the Shh pathway bidirectionally, with a significant induction of Shh, Ptc, and Smo after hyperthyroidism and a decline in Smo expression in the hypothyroid brain. Short-term T₃ administration resulted in a significant induction of cortical Shh mRNA expression and also enhanced reporter gene expression in Shh(+/LacZ) mice. Further, acute T₃ treatment of cortical neuronal cultures resulted in a rapid and significant increase in Shh mRNA, suggesting direct effects. Chromatin immunoprecipitation assays performed on adult neocortex indicated enhanced histone acetylation at the Shh promoter after acute T₃ administration, providing further support that Shh is a thyroid hormone-responsive gene. Our results indicate that maternal and adult-onset perturbations of euthyroid status cause robust and region-specific changes in the Shh pathway in the embryonic and adult forebrain, implicating Shh as a possible mechanistic link for specific neurodevelopmental effects of thyroid hormone.

  13. Barhl1 is directly regulated by thyroid hormone in the developing cerebellum of mice

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Hongyan, E-mail: hongyan_dong@hc-sc.gc.ca [Hazard Identification Division, Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, Ontario, Canada K1A 0K9 (Canada); Yauk, Carole L. [Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, Ontario, Canada K1A 0K9 (Canada); Wade, Michael G. [Hazard Identification Division, Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, Ontario, Canada K1A 0K9 (Canada)

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Thyroid hormone receptor binds to the promoter region of Barhl1. Black-Right-Pointing-Pointer Barhl1 expression in cerebellum is negatively regulated by thyroid hormone. Black-Right-Pointing-Pointer Negative regulation of Barhl1 by thyroid hormone was confirmed in vitro. Black-Right-Pointing-Pointer Thyroid hormone may play a role in normal brain development through transcriptional control of Barhl1. -- Abstract: Thyroid hormones (THs) are essential for the brain development. Despite considerable effort, few genes directly regulated by THs have been identified. In this study, we investigate the effects of THs on the regulation of Barhl1, a transcription factor that regulates sensorineural development. Using DNA microarray combined with chromatin immunoprecipitation (ChIP-chip), we identified a TR{beta} binding site in the promoter of Barhl1. The binding was further confirmed by ChIP-PCR. The site is located approximately 755 bp upstream of the transcription start site. Reporter vectors containing the binding site or mutated fragments were transfected into GH3 cells. T3 treatment decreased the transcriptional activity of the wild fragment but not the mutant. Two 28 bp oligonucleotides containing sequences that resemble known TH response elements (TREs) were derived from this binding site and DNA-protein interaction was performed using electrophoretic mobility shift assays (EMSA). Binding analysis in a nuclear extract containing TR{beta} revealed that one of these fragments bound TR{beta}. This complex was shifted with the addition of anti-TR{beta} antibody. We investigated Barhl1 expression in animal models and TH-treated cultured cells. Both long term treatment with 6-propyl-2-thiouracil and short-term treatment with 0.05% methimazole/1% sodium perchlorate (both treatments render mice hypothyroid) resulted in up-regulation of Barhl1. TH supplementation of hypothyroid mice caused a decrease in the expression of Barhl1

  14. Barhl1 is directly regulated by thyroid hormone in the developing cerebellum of mice

    International Nuclear Information System (INIS)

    Dong, Hongyan; Yauk, Carole L.; Wade, Michael G.

    2011-01-01

    Highlights: ► Thyroid hormone receptor binds to the promoter region of Barhl1. ► Barhl1 expression in cerebellum is negatively regulated by thyroid hormone. ► Negative regulation of Barhl1 by thyroid hormone was confirmed in vitro. ► Thyroid hormone may play a role in normal brain development through transcriptional control of Barhl1. -- Abstract: Thyroid hormones (THs) are essential for the brain development. Despite considerable effort, few genes directly regulated by THs have been identified. In this study, we investigate the effects of THs on the regulation of Barhl1, a transcription factor that regulates sensorineural development. Using DNA microarray combined with chromatin immunoprecipitation (ChIP-chip), we identified a TRβ binding site in the promoter of Barhl1. The binding was further confirmed by ChIP-PCR. The site is located approximately 755 bp upstream of the transcription start site. Reporter vectors containing the binding site or mutated fragments were transfected into GH3 cells. T3 treatment decreased the transcriptional activity of the wild fragment but not the mutant. Two 28 bp oligonucleotides containing sequences that resemble known TH response elements (TREs) were derived from this binding site and DNA–protein interaction was performed using electrophoretic mobility shift assays (EMSA). Binding analysis in a nuclear extract containing TRβ revealed that one of these fragments bound TRβ. This complex was shifted with the addition of anti-TRβ antibody. We investigated Barhl1 expression in animal models and TH-treated cultured cells. Both long term treatment with 6-propyl-2-thiouracil and short-term treatment with 0.05% methimazole/1% sodium perchlorate (both treatments render mice hypothyroid) resulted in up-regulation of Barhl1. TH supplementation of hypothyroid mice caused a decrease in the expression of Barhl1 compared to control animals. Similarly, the expression of Barhl1 in cultured GH3 decreased with the addition of T3. Given

  15. Revisiting available knowledge on teleostean thyroid hormone receptors.

    Science.gov (United States)

    Lazcano, Iván; Orozco, Aurea

    2018-03-21

    Teleosts are the most numerous class of living vertebrates. They exhibit great diversity in terms of morphology, developmental strategies, ecology and adaptation. In spite of this diversity, teleosts conserve similarities at molecular, cellular and endocrine levels. In the context of thyroidal systems, and as in the rest of vertebrates, thyroid hormones in fish regulate development, growth and metabolism by actively entering the nucleus and interacting with thyroid hormone receptors, the final sensors of this endocrine signal, to regulate gene expression. In general terms, vertebrates express the functional thyroid hormone receptors alpha and beta, encoded by two distinct genes (thra and thrb, respectively). However, different species of teleosts express thyroid hormone receptor isoforms with particular structural characteristics that confer singular functional traits to these receptors. For example, teleosts contain two thra genes and in some species also two thrb; some of the expressed isoforms can bind alternative ligands. Also, some identified isoforms contain deletions or large insertions that have not been described in other vertebrates and that have not yet been functionally characterized. As in amphibians, the regulation of some of these teleost isoforms coincides with the climax of metamorphosis and/or life transitions during development and growth. In this review, we aimed to gain further insights into thyroid signaling from a comparative perspective by proposing a systematic nomenclature for teleost thyroid hormone receptor isoforms and summarize their particular functional features when the information was available. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Association between thyroid hormones and TRAIL.

    Science.gov (United States)

    Bernardi, Stella; Bossi, Fleur; Toffoli, Barbara; Giudici, Fabiola; Bramante, Alessandra; Furlanis, Giulia; Stenner, Elisabetta; Secchiero, Paola; Zauli, Giorgio; Carretta, Renzo; Fabris, Bruno

    2017-11-01

    Recent studies suggest that a circulating protein called TRAIL (TNF-related apoptosis-inducing ligand) might have a role in the regulation of body weight and metabolism. Interestingly, thyroid hormones seem to increase TRAIL tissue expression. This study aimed at evaluating whether overt thyroid disorders affected circulating TRAIL levels. TRAIL circulating levels were measured in euthyroid, hyperthyroid, and hypothyroid patients before and after thyroid function normalization. Univariate and multivariate analyses were performed to evaluate the correlation between thyroid hormones and TRAIL. Then, the stimulatory effect of both triiodothyronine (T3) and thyroxine (T4) on TRAIL was evaluated in vitro on peripheral blood mononuclear cells. Circulating levels of TRAIL significantly increased in hyperthyroid and decreased in hypothyroid patients as compared to controls. Once thyroid function was restored, TRAIL levels normalized. There was an independent association between TRAIL and both fT3 and fT4. Consistent with these findings, T3 and T4 stimulated TRAIL release in vitro. Here we show that thyroid hormones are associated with TRAIL expression in vivo and stimulate TRAIL expression in vitro. Given the overlap between the metabolic effects of thyroid hormones and TRAIL, this work sheds light on the possibility that TRAIL might be one of the molecules mediating thyroid hormones peripheral effects. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Action of specific thyroid hormone receptor α(1) and β(1) antagonists in the central and peripheral regulation of thyroid hormone metabolism in the rat.

    Science.gov (United States)

    van Beeren, Hermina C; Kwakkel, Joan; Ackermans, Mariëtte T; Wiersinga, Wilmar M; Fliers, Eric; Boelen, Anita

    2012-12-01

    The iodine-containing drug amiodarone (Amio) and its noniodine containing analogue dronedarone (Dron) are potent antiarrhythmic drugs. Previous in vivo and in vitro studies have shown that the major metabolite of Amio, desethylamiodarone, acts as a thyroid hormone receptor (TR) α(1) and β(1) antagonist, whereas the major metabolite of Dron debutyldronedarone acts as a selective TRα(1) antagonist. In the present study, Amio and Dron were used as tools to discriminate between TRα(1) or TRβ(1) regulated genes in central and peripheral thyroid hormone metabolism. Three groups of male rats received either Amio, Dron, or vehicle by daily intragastric administration for 2 weeks. We assessed the effects of treatment on triiodothyronine (T(3)) and thyroxine (T(4)) plasma and tissue concentrations, deiodinase type 1, 2, and 3 mRNA expressions and activities, and thyroid hormone transporters monocarboxylate transporter 8 (MCT8), monocarboxylate transporter 10 (MCT10), and organic anion transporter 1C1 (OATP1C1). Amio treatment decreased serum T(3), while serum T(4) and thyrotropin (TSH) increased compared to Dron-treated and control rats. At the central level of the hypothalamus-pituitary-thyroid axis, Amio treatment decreased hypothalamic thyrotropin releasing hormone (TRH) expression, while increasing pituitary TSHβ and MCT10 mRNA expression. Amio decreased the pituitary D2 activity. By contrast, Dron treatment resulted in decreased hypothalamic TRH mRNA expression only. Upon Amio treatment, liver T(3) concentration decreased substantially compared to Dron and control rats (50%, p<0.01), but liver T(4) concentration was unaffected. In addition, liver D1, mRNA, and activity decreased, while the D3 activity and mRNA increased. Liver MCT8, MCT10, and OATP1C1 mRNA expression were similar between groups. Our results suggest an important role for TRα1 in the regulation of hypothalamic TRH mRNA expression, whereas TRβ plays a dominant role in pituitary and liver thyroid

  18. Transcriptional regulation by nonclassical action of thyroid hormone

    Directory of Open Access Journals (Sweden)

    Moeller Lars C

    2011-08-01

    Full Text Available Abstract Thyroid hormone (TH is essential for normal development, growth and metabolism. Its effects were thought to be principally mediated through triiodothyronine (T3, acting as a ligand for the nuclear TH receptors (TRs α and β residing on thyroid hormone response elements (TREs in the promoter of TH target genes. In this classical model of TH action, T3 binding to TRs leads to recruitment of basal transcription factors and increased transcription of TH responsive genes. Recently, the concept of TH action on gene expression has become more diverse and now includes nonclassical actions of T3 and T4: T3 has been shown to activate PI3K via the TRs, which ultimately increases transcription of certain genes, e.g. HIF-1α. Additionally, both T3 and thyroxine (T4 can bind to a membrane integrin, αvβ3, which leads to activation of the PI3K and MAPK signal transduction pathways and finally also increases gene transcription, e.g. of the FGF2 gene. Therefore, these initially nongenomic, nonclassical actions seem to serve as additional interfaces for transcriptional regulation by TH. Aim of this perspective is to summarize the genes that are currently known to be induced by nonclassical TH action and the mechanisms involved.

  19. Thyroid stimulating hormone and subclinical thyroid dysfunction

    International Nuclear Information System (INIS)

    Guo Yongtie

    2008-01-01

    Subclinical thyroid dysfunction has mild clinical symptoms. It is nonspecific and not so noticeable. It performs only for thyroid stimulating hormone rise and decline. The value of early diagnosis and treatment of thyroid stimulating hormone in subclinical thyroid dysfunction were reviewed. (authors)

  20. Thyroid hormones states and brain development interactions.

    Science.gov (United States)

    Ahmed, Osama M; El-Gareib, A W; El-Bakry, A M; Abd El-Tawab, S M; Ahmed, R G

    2008-04-01

    The action of thyroid hormones (THs) in the brain is strictly regulated, since these hormones play a crucial role in the development and physiological functioning of the central nervous system (CNS). Disorders of the thyroid gland are among the most common endocrine maladies. Therefore, the objective of this study was to identify in broad terms the interactions between thyroid hormone states or actions and brain development. THs regulate the neuronal cytoarchitecture, neuronal growth and synaptogenesis, and their receptors are widely distributed in the CNS. Any deficiency or increase of them (hypo- or hyperthyroidism) during these periods may result in an irreversible impairment, morphological and cytoarchitecture abnormalities, disorganization, maldevelopment and physical retardation. This includes abnormal neuronal proliferation, migration, decreased dendritic densities and dendritic arborizations. This drastic effect may be responsible for the loss of neurons vital functions and may lead, in turn, to the biochemical dysfunctions. This could explain the physiological and behavioral changes observed in the animals or human during thyroid dysfunction. It can be hypothesized that the sensitive to the thyroid hormones is not only remarked in the neonatal period but also prior to birth, and THs change during the development may lead to the brain damage if not corrected shortly after the birth. Thus, the hypothesis that neurodevelopmental abnormalities might be related to the thyroid hormones is plausible. Taken together, the alterations of neurotransmitters and disturbance in the GABA, adenosine and pro/antioxidant systems in CNS due to the thyroid dysfunction may retard the neurogenesis and CNS growth and the reverse is true. In general, THs disorder during early life may lead to distortions rather than synchronized shifts in the relative development of several central transmitter systems that leads to a multitude of irreversible morphological and biochemical

  1. Thyroid hormone synthesis and anti-thyroid drugs

    Indian Academy of Sciences (India)

    The inhibition of thyroid hormone synthesis is required for the treatment of hyperthyroidism and this can be achieved by one or more anti-thyroid drugs. The most widely used anti-thyroid drug methimazole (MMI) inhibits the production of thyroid hormones by irreversibly inactivating the enzyme TPO. Our studies show that the ...

  2. Thyroid Hormone Receptor Mutations in Cancer and Resistance to Thyroid Hormone: Perspective and Prognosis

    Directory of Open Access Journals (Sweden)

    Meghan D. Rosen

    2011-01-01

    Full Text Available Thyroid hormone, operating through its receptors, plays crucial roles in the control of normal human physiology and development; deviations from the norm can give rise to disease. Clinical endocrinologists often must confront and correct the consequences of inappropriately high or low thyroid hormone synthesis. Although more rare, disruptions in thyroid hormone endocrinology due to aberrations in the receptor also have severe medical consequences. This review will focus on the afflictions that are caused by, or are closely associated with, mutated thyroid hormone receptors. These include Resistance to Thyroid Hormone Syndrome, erythroleukemia, hepatocellular carcinoma, renal clear cell carcinoma, and thyroid cancer. We will describe current views on the molecular bases of these diseases, and what distinguishes the neoplastic from the non-neoplastic. We will also touch on studies that implicate alterations in receptor expression, and thyroid hormone levels, in certain oncogenic processes.

  3. Thyroid Hormone Treatment

    Science.gov (United States)

    ... THYROID HORMONES? Desiccated ( dried and powdered ) animal thyroid ( Armour ®), now mainly obtained from pigs, was the most ... hormone can increase the risk or heart rhythm problems and bone loss making the use of thyroxine ...

  4. Thyroid Hormone and the Neuroglia: Both Source and Target

    Directory of Open Access Journals (Sweden)

    Petra Mohácsik

    2011-01-01

    Full Text Available Thyroid hormone plays a crucial role in the development and function of the nervous system. In order to bind to its nuclear receptor and regulate gene transcription thyroxine needs to be activated in the brain. This activation occurs via conversion of thyroxine to T3, which is catalyzed by the type 2 iodothyronine deiodinase (D2 in glial cells, in astrocytes, and tanycytes in the mediobasal hypothalamus. We discuss how thyroid hormone affects glial cell function followed by an overview on the fine-tuned regulation of T3 generation by D2 in different glial subtypes. Recent evidence on the direct paracrine impact of glial D2 on neuronal gene expression underlines the importance of glial-neuronal interaction in thyroid hormone regulation as a major regulatory pathway in the brain in health and disease.

  5. Thyroid hormone action in postnatal heart development

    Directory of Open Access Journals (Sweden)

    Ming Li

    2014-11-01

    Full Text Available Thyroid hormone is a critical regulator of cardiac growth and development, both in fetal life and postnatally. Here we review the role of thyroid hormone in postnatal cardiac development, given recent insights into its role in stimulating a burst of cardiomyocyte proliferation in the murine heart in preadolescence; a response required to meet the massive increase in circulatory demand predicated by an almost quadrupling of body weight during a period of about 21 days from birth to adolescence. Importantly, thyroid hormone metabolism is altered by chronic diseases, such as heart failure and ischemic heart disease, as well as in very sick children requiring surgery for congenital heart diseases, which results in low T3 syndrome that impairs cardiovascular function and is associated with a poor prognosis. Therapy with T3 or thyroid hormone analogs has been shown to improve cardiac contractility; however, the mechanism is as yet unknown. Given the postnatal cardiomyocyte mitogenic potential of T3, its ability to enhance cardiac function by promoting cardiomyocyte proliferation warrants further consideration.

  6. Hypophysectomy abolishes rhythms in rat thyroid hormones but not in the thyroid clock

    DEFF Research Database (Denmark)

    Fahrenkrug, J; Georg, B; Hannibal, J

    2017-01-01

    The endocrine body rhythms including the hypothalamic-pituitary-thyroid axis seem to be regulated by the circadian timing system, and daily rhythmicity of circulating thyroid-stimulating hormone (TSH) is well established. The circadian rhythms are generated by endogenous clocks in the central bra...

  7. Thyroid hormone signaling in the hypothalamus

    NARCIS (Netherlands)

    Alkemade, Anneke; Visser, Theo J.; Fliers, Eric

    2008-01-01

    PURPOSE OF REVIEW: Proper thyroid hormone signaling is essential for brain development and adult brain function. Signaling can be disrupted at many levels due to altered thyroid hormone secretion, conversion or thyroid hormone receptor binding. RECENT FINDINGS: Mutated genes involved in thyroid

  8. Radioimmunoassay and the hormones of thyroid function

    International Nuclear Information System (INIS)

    Stahl, R.J.

    1975-01-01

    Radioimmunoassay (RIA) has provided the tools for wide-reaching investigations that have changed and continue to change many important concepts of thyroid physiology and pathophysiology. The RIA for human thyrotropin (TSH) was developed in 1965; development of the RIA for triiodothyronine (T 3 ), thyroxine(T 4 ), thyroxine-binding globulin (TBG), and recently, thyrotropin-releasing hormone (TRH) and thyroglobulin (Tg) followed. The capacity to measure nanogram and picogram concentrations with relative ease and speed has permitted the demonstration of dynamic relationships of the intrathyroidal and circulating thyroid hormones to each other and to the pituitary and hypothalamic regulating hormones. Evidence for the presence of cross-influences between TRH and other hypothalamic regulating hormones on the secretion of pituitary hormones has accumulated. The impact of the new information on clinical practice is now becoming evident. There is new appreciation of the value of assaying serum T 3 and TSH concentrations in the clinical management of patients with disturbed function of the thyroid, pituitary, or hypothalamus. The necessary components for RIA performance can be purchased separately or in kit form from commercial sources. With appropriate quality-control procedures, precise, sensitive, and reliable data can be generated. Awareness of the specific technical problems relating to the RIA of these hormones is absolutely necessary to assure reliable results. The availability of kits or their components permits the performance of these studies in the community hospital and in reliable commercial-service laboratories. (U.S.)

  9. Expression of neuropeptide W in rat stomach mucosa: regulation by nutritional status, glucocorticoids and thyroid hormones.

    Science.gov (United States)

    Caminos, Jorge E; Bravo, Susana B; García-Rendueles, María E R; Ruth González, C; Garcés, Maria F; Cepeda, Libia A; Lage, Ricardo; Suárez, Miguel A; López, Miguel; Diéguez, Carlos

    2008-02-07

    Neuropeptide W (NPW) is a recently identified neuropeptide that binds to G-protein-coupled receptor 7 (GPR7) and 8 (GPR8). In rodent brain, NPW mRNA is confined to specific nuclei in hypothalamus, midbrain and brainstem. Expression of NPW mRNA has also been confirmed in peripheral organs such as stomach. Several reports suggested that brain NPW is implicated in the regulation of energy and hormonal homeostasis, namely the adrenal and thyroid axes; however the precise physiological role and regulation of peripheral NPW remains unclear. In this study, we examined the effects of nutritional status on the regulation of NPW in stomach mucosa. Our results show that in this tissue, NPW mRNA and protein expression is negatively regulated by fasting and food restriction, in all the models we studied: males, females and pregnant females. Next, we examined the effect of glucocorticoids and thyroid hormones on NPW mRNA expression in the stomach mucosa. Our data showed that NPW expression is decreased in this tissue after glucocorticoid treatment or hyperthyroidism. Conversely, hypothyroidism induces a marked increase in the expression of NPW in rat stomach. Overall, these data indicate that stomach NPW is regulated by nutritional and hormonal status.

  10. Thyroid Stimulating Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Murat Tuncel

    2017-02-01

    Full Text Available Thyroid stimulating hormone receptor (TSHR plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.

  11. Thyroid hormone therapy following the thyroidectomy for thyroid carcinoma

    International Nuclear Information System (INIS)

    Horster, F.A.

    1986-01-01

    Medication with thyroid hormones following total thyroidectomy for thyroid carcinoma is based on the following principles: 1. The patient is informed about the lifelong necessity of taking a thyroid hormones daily before breakfast. This hormone must be given orally and its bioligical effect is identical with that of the tyhroid hormone secreted by the healthy thyroid gland. 2. The daily dosage of thyroid hormones may be assessed on the basis of the following parameters: a) the patient's clinical euthyroidism, b) suppression of thyrotropic activity, c) unrestricted tolerance of the preparation. 3. The in vitro parameters associated with optimal medication should be within the following ranges: Thyroxine value (TT4 or FT4): above the normal range, triiodothyronine value (TT3 or FT3): within the upper normal range and thyrotropin value (TSH 'ultrasensitive' or TRH-test): suppressed. (orig.) [de

  12. Evidence of a bigenomic regulation of mitochondrial gene expression by thyroid hormone during rat brain development

    International Nuclear Information System (INIS)

    Sinha, Rohit Anthony; Pathak, Amrita; Mohan, Vishwa; Babu, Satish; Pal, Amit; Khare, Drirh; Godbole, Madan M.

    2010-01-01

    Hypothyroidism during early mammalian brain development is associated with decreased expression of various mitochondrial encoded genes along with evidence for mitochondrial dysfunction. However, in-spite of the similarities between neurological disorders caused by perinatal hypothyroidism and those caused by various genetic mitochondrial defects we still do not know as to how thyroid hormone (TH) regulates mitochondrial transcription during development and whether this regulation by TH is nuclear mediated or through mitochondrial TH receptors? We here in rat cerebellum show that hypothyroidism causes reduction in expression of nuclear encoded genes controlling mitochondrial biogenesis like PGC-1α, NRF-1α and Tfam. Also, we for the first time demonstrate a mitochondrial localization of thyroid hormone receptor (mTR) isoform in developing brain capable of binding a TH response element (DR2) present in D-loop region of mitochondrial DNA. These results thus indicate an integrated nuclear-mitochondrial cross talk in regulation of mitochondrial transcription by TH during brain development.

  13. Evidence of a bigenomic regulation of mitochondrial gene expression by thyroid hormone during rat brain development

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Rohit Anthony; Pathak, Amrita; Mohan, Vishwa; Babu, Satish; Pal, Amit; Khare, Drirh [Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014 (India); Godbole, Madan M., E-mail: madangodbole@yahoo.co.in [Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014 (India)

    2010-07-02

    Hypothyroidism during early mammalian brain development is associated with decreased expression of various mitochondrial encoded genes along with evidence for mitochondrial dysfunction. However, in-spite of the similarities between neurological disorders caused by perinatal hypothyroidism and those caused by various genetic mitochondrial defects we still do not know as to how thyroid hormone (TH) regulates mitochondrial transcription during development and whether this regulation by TH is nuclear mediated or through mitochondrial TH receptors? We here in rat cerebellum show that hypothyroidism causes reduction in expression of nuclear encoded genes controlling mitochondrial biogenesis like PGC-1{alpha}, NRF-1{alpha} and Tfam. Also, we for the first time demonstrate a mitochondrial localization of thyroid hormone receptor (mTR) isoform in developing brain capable of binding a TH response element (DR2) present in D-loop region of mitochondrial DNA. These results thus indicate an integrated nuclear-mitochondrial cross talk in regulation of mitochondrial transcription by TH during brain development.

  14. Thyroid hormones and fetal brain development.

    Science.gov (United States)

    Pemberton, H N; Franklyn, J A; Kilby, M D

    2005-08-01

    Thyroid hormones are intricately involved in the developing fetal brain. The fetal central nervous system is sensitive to the maternal thyroid status. Critical amounts of maternal T3 and T4 must be transported across the placenta to the fetus to ensure the correct development of the brain throughout ontogeny. Severe mental retardation of the child can occur due to compromised iodine intake or thyroid disease. This has been reported in areas of the world with iodine insufficiency, New Guinea, and also in mother with thyroid complications such as hypothyroxinaemia and hyperthyroidism. The molecular control of thyroid hormones by deiodinases for the activation of thyroid hormones is critical to ensure the correct amount of active thyroid hormones are temporally supplied to the fetus. These hormones provide timing signals for the induction of programmes for differentiation and maturation at specific stages of development. Understanding these molecular mechanisms further will have profound implications in the clinical management of individuals affected by abnormal maternal of fetal thyroid status.

  15. Paradigm Shift in Thyroid Hormone Mechanism of Action | Center for Cancer Research

    Science.gov (United States)

    Thyroid hormone (TH) is one of the primary endocrine regulators of human metabolism and homeostasis. Acting through three forms of the thyroid hormone receptor (THR; alpha-1, beta-1, and beta-2), TH regulates target gene expression in nearly every cell in the body, modulating fundamental processes, such as basal metabolic rate, long bone growth, and neural maturation. TH is

  16. Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

    Directory of Open Access Journals (Sweden)

    Rafael Simó

    Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

  17. Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

    Science.gov (United States)

    Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

    2014-01-01

    Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

  18. Thyroid hormone regulation of adult intestinal stem cells: Implications on intestinal development and homeostasis.

    Science.gov (United States)

    Sun, Guihong; Roediger, Julia; Shi, Yun-Bo

    2016-12-01

    Organ-specific adult stem cells are essential for organ homeostasis, tissue repair and regeneration. The formation of such stem cells often takes place during postembryonic development, a period around birth in mammals when plasma thyroid hormone concentration is high. The life-long self-renewal of the intestinal epithelium has made mammalian intestine a valuable model to study the function and regulation and adult stem cells. On the other hand, much less is known about how the adult intestinal stem cells are formed during vertebrate development. Here, we will review some recent progresses on this subject, focusing mainly on the formation of the adult intestine during Xenopus metamorphosis. We will discuss the role of thyroid hormone signaling pathway in the process and potential molecular conservations between amphibians and mammals as well as the implications in organ homeostasis and human diseases.

  19. Generalized resistance to thyroid hormone associated with a mutation in the ligand-binding domain of the human thyroid hormone receptor β

    International Nuclear Information System (INIS)

    Sakurai, A.; Takeda, K.; Ain, K.; Ceccarelli, P.; Nakai, A.; Seino, S.; Bell, G.I.; Refetoff, S.; DeGroot, L.J.

    1989-01-01

    The syndrome of generalized resistance to thyroid hormone is characterized by elevated circulating levels of thyroid hormone in the presence of an overall eumetabolic state and failure to respond normally to triiodothyronine. The authors have evaluated a family with inherited generalized resistance to thyroid hormone for abnormalities in the thyroid hormone nuclear receptors. A single guanine → cytosine replacement in the codon for amino acid 340 resulted in a glycine → arginine substitution in the hormone-binding domain of one of two alleles of the patient's thyroid hormone nuclear receptor β gene. In vitro translation products of this mutant human thyroid hormone nuclear receptor β gene did not bind triiodothyronine. Thus, generalized resistance to thyroid hormone can result from expression of an abnormal thyroid hormone nuclear receptor molecule

  20. Thyroid hormone metabolism in poultry

    Directory of Open Access Journals (Sweden)

    Darras V.M.

    2000-01-01

    Full Text Available Thyroid hormone (TH receptors preferentially bind 3.5,3'-triiodothyronine (T3. Therefore the metabolism of thyroxine (T4 secreted by the thyroid gland in peripheral tissues, resulting in the production and degradation of receptor-active T3, plays a major role in thyroid function. The most important metabolic pathway for THs is deiodination. Another important pathway is sulfation, which is a reversible pathway that has been shown to interact with TH deiodination efficiency. The enzymes catalysing TH deiodination consist of three types. Type 1 deiodinase (D1 catalyses both outer ring (ORD and inner ring deiodinalion (IRD. Type II deiodinase (D2 only catalyses ORD while type III (D3 only catalyses IRD. The three chicken deiodinase cDNAs have been cloned recently. These enzymes all belong to the family of selenoproteins. Ontogenetic studies show that the availability of deiodinases is regulated in a tissue specific and developmental stage dependent way. Characteristic for the chicken is the presence of very high levels off, inactivating D3 enzyme in the embryonic liver. Hepatic D3 is subject to acute regulation in a number of situations. Both growth hormone and glucocorticoid injection rapidly decrease hepatic D3 levels, hereby increasing plasma T3 without affecting hepatic D1 levels. The inhibition of D3 seems to be regulated mainly at the level of D3 gene transcription. The effect of growth hormone on D3 expression persists throughout life, while glucocorticoids start to inhibit hepatic D1 expression in posthatch chickens. Food restriction in growing chickens increases hepatic D3 levels. This contributes to the decrease in plasma T3 necessary to reduce energy loss. Refeeding restores hepatic D3 and plasma T3 to control levels within a few hours. It can be concluded that the tissue and time dependent regulation of the balance between TH activating and inactivating enzymes plays an essential role in the control of local T3 availability and hence in

  1. Role of Thyroid Hormones in Skeletal Development and Bone Maintenance.

    Science.gov (United States)

    Bassett, J H Duncan; Williams, Graham R

    2016-04-01

    The skeleton is an exquisitely sensitive and archetypal T3-target tissue that demonstrates the critical role for thyroid hormones during development, linear growth, and adult bone turnover and maintenance. Thyrotoxicosis is an established cause of secondary osteoporosis, and abnormal thyroid hormone signaling has recently been identified as a novel risk factor for osteoarthritis. Skeletal phenotypes in genetically modified mice have faithfully reproduced genetic disorders in humans, revealing the complex physiological relationship between centrally regulated thyroid status and the peripheral actions of thyroid hormones. Studies in mutant mice also established the paradigm that T3 exerts anabolic actions during growth and catabolic effects on adult bone. Thus, the skeleton represents an ideal physiological system in which to characterize thyroid hormone transport, metabolism, and action during development and adulthood and in response to injury. Future analysis of T3 action in individual skeletal cell lineages will provide new insights into cell-specific molecular mechanisms and may ultimately identify novel therapeutic targets for chronic degenerative diseases such as osteoporosis and osteoarthritis. This review provides a comprehensive analysis of the current state of the art.

  2. Recent Advances in Thyroid Hormone Regulation: Toward a New Paradigm for Optimal Diagnosis and Treatment

    OpenAIRE

    Rudolf Hoermann; John E. M. Midgley; Rolf Larisch; Johannes W. Dietrich; Johannes W. Dietrich; Johannes W. Dietrich

    2017-01-01

    In thyroid health, the pituitary hormone thyroid-stimulating hormone (TSH) raises glandular thyroid hormone production to a physiological level and enhances formation and conversion of T4 to the biologically more active T3. Overstimulation is limited by negative feedback control. In equilibrium defining the euthyroid state, the relationship between TSH and FT4 expresses clusters of genetically determined, interlocked TSH–FT4 pairs, which invalidates their statistical correlation within the eu...

  3. Thyroid hormone antibodies and Hashimoto's thyroiditis in mongrel dogs

    Energy Technology Data Exchange (ETDEWEB)

    Rajatanavin, R.; Fang, S.L.; Pino, S.; Laurberg, P.; Braverman, L.E.; Smith, M.; Bullock, L.P.

    1989-05-01

    Abnormally elevated serum T3 concentrations measured by RIA were observed in 19 clinically euthyroid or hypothyroid mongrel dogs. The serum T4 concentrations in these sera were low, normal, or high. Measurement of the intensity of thyroid hormone binding to serum proteins was determined by equilibrium dialysis. A marked decrease in the percent free T3 was observed in these abnormal sera. Polyacrylamide gel electrophoresis, pH 7.4, of normal dog serum enriched with tracer /sup 125/I-labeled thyroid hormones demonstrated binding of (/sup 125/I)T4 to transthyretin, thyroid hormone-binding globulin, and albumin and of (/sup 125/I)T3 primarily to thyroid hormone-binding globulin. In all abnormal sera, polyacrylamide gel electrophoresis demonstrated strikingly higher binding of T3 to immunoglobulin (Ig). Eleven of 16 abnormal sera had minimal to moderate binding of T4 to Ig. The percent free T4 was lower only in dogs whose sera demonstrated markedly increased binding of T4 to Ig. All abnormal sera tested had positive antithyroglobulin antibodies, consistent with the diagnosis of autoimmune lymphocytic thyroiditis. As in humans, antibodies to thyroid hormones in dogs are more common in the presence of Hashimoto's thyroiditis and should be considered when elevated serum thyroid hormone concentrations are observed in the absence of clinical thyrotoxicosis. When an antibody to only one thyroid hormone is present, a marked discrepancy in the serum concentrations of T3 and T4 will be observed.

  4. Identification of a novel modulator of thyroid hormone receptor-mediated action.

    Directory of Open Access Journals (Sweden)

    Bernhard G Baumgartner

    Full Text Available BACKGROUND: Diabetes is characterized by reduced thyroid function and altered myogenesis after muscle injury. Here we identify a novel component of thyroid hormone action that is repressed in diabetic rat muscle. METHODOLOGY/PRINCIPAL FINDINGS: We have identified a gene, named DOR, abundantly expressed in insulin-sensitive tissues such as skeletal muscle and heart, whose expression is highly repressed in muscle from obese diabetic rats. DOR expression is up-regulated during muscle differentiation and its loss-of-function has a negative impact on gene expression programmes linked to myogenesis or driven by thyroid hormones. In agreement with this, DOR enhances the transcriptional activity of the thyroid hormone receptor TR(alpha1. This function is driven by the N-terminal part of the protein. Moreover, DOR physically interacts with TR( alpha1 and to T(3-responsive promoters, as shown by ChIP assays. T(3 stimulation also promotes the mobilization of DOR from its localization in nuclear PML bodies, thereby indicating that its nuclear localization and cellular function may be related. CONCLUSIONS/SIGNIFICANCE: Our data indicate that DOR modulates thyroid hormone function and controls myogenesis. DOR expression is down-regulated in skeletal muscle in diabetes. This finding may be of relevance for the alterations in muscle function associated with this disease.

  5. Maintaining euthyroidism: fundamentals of thyroid hormone ...

    African Journals Online (AJOL)

    Thyroid-related pathologies, especially subclinical and clinical hypothyroidism, are commonly described in clinical practice. While illnesses related to aberrant thyroid hormone homeostasis are the most prevalent endocrinological conditions diagnosed, important aspects related to thyroid hormone physiology are often ...

  6. Effects of thyroid hormones on the heart.

    Science.gov (United States)

    Vargas-Uricoechea, Hernando; Bonelo-Perdomo, Anilsa; Sierra-Torres, Carlos Hernán

    2014-01-01

    Thyroid hormones have a significant impact on heart function, mediated by genomic and non-genomic effects. Consequently, thyroid hormone deficiencies, as well as excesses, are expected to result in profound changes in cardiac function regulation and cardiovascular hemodynamics. Thyroid hormones upregulate the expression of the sarcoplasmic reticulum calcium-activated ATPase and downregulate the expression of phospholamban. Overall, hyperthyroidism is characterized by an increase in resting heart rate, blood volume, stroke volume, myocardial contractility, and ejection fraction. The development of "high-output heart failure" in hyperthyroidism may be due to "tachycardia-mediated cardiomyopathy". On the other hand, in a hypothyroid state, thyroid hormone deficiency results in lower heart rate and weakening of myocardial contraction and relaxation, with prolonged systolic and early diastolic times. Cardiac preload is decreased due to impaired diastolic function. Cardiac afterload is increased, and chronotropic and inotropic functions are reduced. Subclinical thyroid dysfunction is relatively common in patients over 65 years of age. In general, subclinical hypothyroidism increases the risk of coronary heart disease (CHD) mortality and CHD events, but not of total mortality. The risk of CHD mortality and atrial fibrillation (but not other outcomes) in subclinical hyperthyroidism is higher among patients with very low levels of thyrotropin. Finally, medications such as amiodarone may induce hypothyroidism (mediated by the Wolff-Chaikoff), as well as hyperthyroidism (mediated by the Jod-Basedow effect). In both instances, the underlying cause is the high concentration of iodine in this medication. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  7. Liver X receptor β controls thyroid hormone feedback in the brain and regulates browning of subcutaneous white adipose tissue.

    Science.gov (United States)

    Miao, Yifei; Wu, Wanfu; Dai, Yubing; Maneix, Laure; Huang, Bo; Warner, Margaret; Gustafsson, Jan-Åke

    2015-11-10

    The recent discovery of browning of white adipose tissue (WAT) has raised great research interest because of its significant potential in counteracting obesity and type 2 diabetes. Browning is the result of the induction in WAT of a newly discovered type of adipocyte, the beige cell. When mice are exposed to cold or several kinds of hormones or treatments with chemicals, specific depots of WAT undergo a browning process, characterized by highly activated mitochondria and increased heat production and energy expenditure. However, the mechanisms underlying browning are still poorly understood. Liver X receptors (LXRs) are one class of nuclear receptors, which play a vital role in regulating cholesterol, triglyceride, and glucose metabolism. Following our previous finding that LXRs serve as repressors of uncoupling protein-1 (UCP1) in classic brown adipose tissue in female mice, we found that LXRs, especially LXRβ, also repress the browning process of subcutaneous adipose tissue (SAT) in male rodents fed a normal diet. Depletion of LXRs activated thyroid-stimulating hormone (TSH)-releasing hormone (TRH)-positive neurons in the paraventricular nucleus area of the hypothalamus and thus stimulated secretion of TSH from the pituitary. Consequently, production of thyroid hormones in the thyroid gland and circulating thyroid hormone level were increased. Moreover, the activity of thyroid signaling in SAT was markedly increased. Together, our findings have uncovered the basis of increased energy expenditure in male LXR knockout mice and provided support for targeting LXRs in treatment of obesity.

  8. Radioimmunoassay of thyroid hormones

    International Nuclear Information System (INIS)

    Bartalena, L.; Mariotti, S.; Pinchera, A.

    1987-01-01

    For many years, methods based on iodine content determination have represented the only techniques available for the estimation of total thyroid hormone concentrations in serum. Subsequently, simple, sensitive, and specific radioligand assays for thyroid hormones have replaced these chemical methods. For the purpose of this chapter, iodometric techniques are only briefly summarized for their historical importance, whereas attention is focused on radioligand assays

  9. Effect of adrenal hormones on thyroid secretion and thyroid hormones on adrenal secretion in the sheep.

    Science.gov (United States)

    Falconer, I R; Jacks, F

    1975-01-01

    1. Previous work has shown that after stressful stimuli, sheep initially secrete increased amounts of thyroid hormone, at a time when adrenal secretion is also elevated. 2. This study was designed to evaluate (a) any short-term activation or inhibition of thyroid secretion by exogenous cortisol or ACTH administered in quantities comparable to those secreted after stress in sheep and (b) any short-term effect that exogenous thyroxine or triiodothyronine may have on the concentration of plasma cortisol in the sheep. 3. Thyroid activity was measured by determination of plasma protein bound 125I (PB125I) and total 125I in thyroid vein and mixed venous (jugular) blood. Plasma cortisol and thyroxine concentrations were measured by a competitive protein-binding assay at intervals for up to 5 hr after commencement of the experiment. 4. No evidence of an activation of thyroid secretion was found during cortisol or ACTH infusion, as monitored by thyroid vein PB125I. Similarly there was no evidence of any inhibition of thyroid function, as measured by continued secretion of thyroid hormones into thyroid vein blood. 5. No effect on plasma cortisol concentration due to thyroid hormone treatment was observed. 6. It was concluded that (a) elevated circulating corticosteroids in physiological concentrations have no short-term effects on thyroid activity in the sheep and (b) the short-term alterations in thyroid and adrenal cortical secretion observed during stress in the sheep could not be attributed to direct interaction of elevated thyroid hormone concentrations with adrenal cortical secretion. PMID:170400

  10. Thyroid hormones regulate selenoprotein expression and selenium status in mice.

    Directory of Open Access Journals (Sweden)

    Jens Mittag

    Full Text Available Impaired expression of selenium-containing proteins leads to perturbed thyroid hormone (TH levels, indicating the central importance of selenium for TH homeostasis. Moreover, critically ill patients with declining serum selenium develop a syndrome of low circulating TH and a central downregulation of the hypothalamus-pituitary-thyroid axis. This prompted us to test the reciprocal effect, i.e., if TH status would also regulate selenoprotein expression and selenium levels. To investigate the TH dependency of selenium metabolism, we analyzed mice expressing a mutant TH receptor α1 (TRα1+m that confers a receptor-mediated hypothyroidism. Serum selenium was reduced in these animals, which was a direct consequence of the mutant TRα1 and not related to their metabolic alterations. Accordingly, hyperthyroidism, genetically caused by the inactivation of TRβ or by oral TH treatment of adult mice, increased serum selenium levels in TRα1+m and controls, thus demonstrating a novel and specific role for TRα1 in selenium metabolism. Furthermore, TH affected the mRNA levels for several enzymes involved in selenoprotein biosynthesis as well as serum selenoprotein P concentrations and the expression of other antioxidative selenoproteins. Taken together, our results show that TH positively affects the serum selenium status and regulates the expression of several selenoproteins. This demonstrates that selenium and TH metabolism are interconnected through a feed-forward regulation, which can in part explain the rapid parallel downregulation of both systems in critical illness.

  11. Control of Pituitary Thyroid-stimulating Hormone Synthesis and Secretion by Thyroid Hormones during Xenopus Metamorphosis

    Science.gov (United States)

    Serum thyroid hormone (TH) concentrations in anuran larvae rise rapidly during metamorphosis. Such a rise in an adult anuran would inevitably trigger a negative feedback response resulting in decreased synthesis and secretion of thyroid-stimulating hormone (TSH) by the pituitary....

  12. New avenues for regulation of lipid metabolism by thyroid hormones and analogs.

    Science.gov (United States)

    Senese, Rosalba; Lasala, Pasquale; Leanza, Cristina; de Lange, Pieter

    2014-01-01

    Weight loss due to negative energy balance is a goal in counteracting obesity and type 2 diabetes mellitus. The thyroid is known to be an important regulator of energy metabolism through the action of thyroid hormones (THs). The classic, active TH, 3,5,3'-triiodo-L-thyronine (T3) acts predominantly by binding to nuclear receptors termed TH receptors (TRs), that recognize TH response elements (TREs) on the DNA, and so regulate transcription. T3 also acts through "non-genomic" pathways that do not necessarily involve TRs. Lipid-lowering therapies have been suggested to have potential benefits, however, the establishment of comprehensive therapeutic strategies is still awaited. One drawback of using T3 in counteracting obesity has been the occurrence of heart rhythm disturbances. These are mediated through one TR, termed TRα. The end of the previous century saw the exploration of TH mimetics that specifically bind to TR beta in order to prevent cardiac disturbances, and TH derivatives such as 3,5-diiodo-L-thyronine (T2), that possess interesting biological activities. Several TH derivatives and functional analogs have low affinity for the TRs, and are suggested to act predominantly through non-genomic pathways. All this has opened new perspectives in thyroid physiology and TH derivative usage as anti-obesity therapies. This review addresses the pros and cons of these compounds, in light of their effects on energy balance regulation and on lipid/cholesterol metabolism.

  13. New Avenues for Regulation of Lipid Metabolism by Thyroid Hormones and Analogs

    Directory of Open Access Journals (Sweden)

    Rosalba eSenese

    2014-12-01

    Full Text Available Weight loss due to negative energy balance is a goal in counteracting obesity and type 2 diabetes mellitus. The thyroid is known to be an important regulator of energy metabolism through the action of thyroid hormones (THs. The classic, active TH, 3,5,3’-triiodo-L-thyronine (T3 acts predominantly by binding to nuclear receptors termed TH receptors (TRs, that recognize TH response elements (TREs on the DNA, and so regulate transcription. T3 also acts through non-genomic pathways that do not necessarily involve TRs. Lipid-lowering therapies have been suggested to have potential benefits, however, the establishment of comprehensive therapeutic strategies is still awaited. One drawback of using T3 in counteracting obesity has been the occurrence of heart rhythm disturbances. These are mediated through one TR, termed TR alpha. The end of the previous century saw the exploration of TH mimetics that specifically bind to TR beta in order to prevent cardiac disturbances, and TH derivatives such as 3,5-diiodo-L-thyronine (T2, that possess interesting biological activities. Several TH derivatives and functional analogs have low affinity for the TRs, and are suggested to act predominantly through non-genomic pathways. All this has opened new perspectives in thyroid physiology and TH derivative usage as anti-obesity therapies. This review addresses the pros and cons of these compounds, in light of their effects on energy balance regulation and on lipid/cholesterol metabolism.

  14. Increased sensitivity of thyroid hormone-mediated signaling despite prolonged fasting.

    Science.gov (United States)

    Martinez, Bridget; Scheibner, Michael; Soñanez-Organis, José G; Jaques, John T; Crocker, Daniel E; Ortiz, Rudy M

    2017-10-01

    Thyroid hormones (TH) can increase cellular metabolism. Food deprivation in mammals is typically associated with reduced thyroid gland responsiveness, in an effort to suppress cellular metabolism and abate starvation. However, in prolonged-fasted, elephant seal pups, cellular TH-mediated proteins are up-regulated and TH levels are maintained with fasting duration. The function and contribution of the thyroid gland to this apparent paradox is unknown and physiologically perplexing. Here we show that the thyroid gland remains responsive during prolonged food deprivation, and that its function and production of TH increase with fasting duration in elephant seals. We discovered that our modeled plasma TH data in response to exogenous thyroid stimulating hormone predicted cellular signaling, which was corroborated independently by the enzyme expression data. The data suggest that the regulation and function of the thyroid gland in the northern elephant seal is atypical for a fasted animal, and can be better described as, "adaptive fasting". Furthermore, the modeling data help substantiate the in vivo responses measured, providing unique insight on hormone clearance, production rates, and thyroid gland responsiveness. Because these unique endocrine responses occur simultaneously with a nearly strict reliance on the oxidation of lipid, these findings provide an intriguing model to better understand the TH-mediated reliance on lipid metabolism that is not otherwise present in morbidly obese humans. When coupled with cellular, tissue-specific responses, these data provide a more integrated assessment of thyroidal status that can be extrapolated for many fasting/food deprived mammals. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Kinetics of thyroid hormones

    International Nuclear Information System (INIS)

    Inada, Mitsuo; Nishikawa, Mitsushige; Naito, Kimikazu; Ishii, Hitoshi; Tanaka, Kiyoshi

    1980-01-01

    Kinetics of thyroid hormones were outlined, and recent progress in metabolism of these hormones was also described. Recently, not only T 4 and T 3 but also rT 3 , 3,3'-T 2 , 3',5'-T 2 , and 3,5-T 2 can be measured by RIA. To clarify metabolic pathways of these hormones, metabolic clearance rate and production rate of these hormones were calculated. As single-compartment analysis was insufficient to clarify disappearance curves of thyroid hormones in blood such as T 3 and T 2 of which metabolic speed was so fast, multi-compartment analysis or non-compartment analysis were also performed. Thyroid hormones seemed to be measured more precisely by constant infusion method. At the first step of T 4 metabolism, T 3 was formed by 5'-monodeiodination of T 4 , and rT 3 was formed by 5-monodeiodination of T 4 . As metabolic pathways of T 3 and rT 3 , conversion of them to 3,3'-T 2 or to 3',5'-T 2 and 3,5-T 2 was supposed. This subject will be an interesting research theme in future. (Tsunoda, M.)

  16. Free thyroid hormones in health and disease

    International Nuclear Information System (INIS)

    Bueber, V.

    1984-01-01

    Several groups of patients with normal and abnormal thyroid function as well as patients with goitre on hormone substitution are discussed with respect to the diagnostic value of the free thyroid hormone methods. The free T 3 technique under investigation separates clearly between euthyroidism and hyperthyroidism, however, during application of contraceptive pills and during pregnancy free T 3 is slightly enhanced. Free T 4 can be found in the normal range even in hypothyroidism, during T 4 substitution free T 4 is useful for control of adequate hormone substitution. Free thyroid hormones are advantageous to be performed with respect to practicability compared to the estimation of total hormone concentrations by enzyme as well as radioimmunoassay. Normally there is no additional demand for measurement of thyroid hormone binding proteins, another rather economical argument for using these parameters in thyroid diagnosis. (orig.) [de

  17. Thyroid hormone negatively regulates CDX2 and SOAT2 mRNA expression via induction of miRNA-181d in hepatic cells

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Chui Sun; Sinha, Rohit Anthony [Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, 8, College Road, Singapore 169857 (Singapore); Ota, Sho; Katsuki, Masahito [Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Yen, Paul Michael, E-mail: paul.yen@duke-nus.edu.sg [Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, 8, College Road, Singapore 169857 (Singapore)

    2013-11-01

    Highlights: •Thyroid hormone induces miR-181d expression in human hepatic cells and mouse livers. •Thyroid hormone downregulates CDX2 and SOAT2 (or ACAT2) via miR-181d. •miR-181d reduces cholesterol output from human hepatic cells. -- Abstract: Thyroid hormones (THs) regulate transcription of many metabolic genes in the liver through its nuclear receptors (TRs). Although the molecular mechanisms for positive regulation of hepatic genes by TH are well understood, much less is known about TH-mediated negative regulation. Recently, several nuclear hormone receptors were shown to downregulate gene expression via miRNAs. To further examine the potential role of miRNAs in TH-mediated negative regulation, we used a miRNA microarray to identify miRNAs that were directly regulated by TH in a human hepatic cell line. In our screen, we discovered that miRNA-181d is a novel hepatic miRNA that was regulated by TH in hepatic cell culture and in vivo. Furthermore, we identified and characterized two novel TH-regulated target genes that were downstream of miR-181d signaling: caudal type homeobox 2 (CDX2) and sterol O-acyltransferase 2 (SOAT2 or ACAT2). CDX2, a known positive regulator of hepatocyte differentiation, was regulated by miR-181d and directly activated SOAT2 gene expression. Since SOAT2 is an enzyme that generates cholesteryl esters that are packaged into lipoproteins, our results suggest miR-181d plays a significant role in the negative regulation of key metabolic genes by TH in the liver.

  18. Thyroid hormones regulate skeletal muscle regeneration after acute injury.

    Science.gov (United States)

    Leal, Anna Lúcia R C; Albuquerque, João Paulo C; Matos, Marina S; Fortunato, Rodrigo S; Carvalho, Denise P; Rosenthal, Doris; da Costa, Vânia Maria Corrêa

    2015-02-01

    We evaluated the effects of hypo- and hyperthyroid statuses during the initial phase of skeletal muscle regeneration in rats. To induce hypo- or hyperthyroidism, adult male Wistar rats were treated with methimazole (0.03%) or T4 (10 μg/100 g), respectively, for 10 days. Three days before sacrifice, a crush injury was produced in the solear muscles of one half of the animals, while the other half remained intact. T3, T4, TSH, and leptin serum levels were not affected by the injury. Serum T3 and T4 levels were significantly increased in hyperthyroid and hyper-injury animals. Hypothyroidism was confirmed by the significant increase in serum TSH levels in hypothyroid and hypo-injury animals. Injury increased cell infiltration and macrophage accumulation especially in hyperthyroid animals. Both type 2 and type 3 deiodinases were induced by lesion, and the opposite occurred with the type 1 isoform, at least in the control and hyperthyroid groups. Injury increased both MyoD and myogenin expression in all the studied groups, but only MyoD expression was increased by thyroidal status only at the protein level. We conclude that thyroid hormones modulate skeletal muscle regeneration possibly by regulating the inflammatory process, as well as MyoD and myogenin expression in the injured tissue.

  19. Comparison level of thyroid and thyroid related hormones between sudanese males and females

    International Nuclear Information System (INIS)

    Madani, H.; Hassan, AME.; Basama, N. K.; Mohamed, W.A.S.; Eltayeb, N. H.; Elsayed, B. B.

    2012-12-01

    The function of the thyroid gland is under the control of pituitary gland through the thyroid stimulating hormone (TSH). It secretes the thyroid hormones tetra-iodo-thyronine (T 4 ) and Tri-iodo-thyronine (T 3 ). More secretion of thyroid hormones (hyperthyroidism) and low secretion (hypothyroidism) sometimes happen. This study was carried out to determine thyroid disorders in patients referred to radioimmunoassay (RIA) laboratory of Sudan Atomic Energy Commission (SAEC) during 2006-2010 for the thyroid function test. Disorders were detected using radioimmunoassay and Immuno radiometric assay. The total number of patients referred during these years were found to be 4700 sudanese patients, among them 4165 were females representing 88.6% compared to 535 males representing 11.4%. The total concentration of thyroid hormones thyroxine (T 4 ), tri iodine thyronine (T 3 ) and thyroid simulating stimulating hormones (TSH) were d terminated the prevalence of euthyroid was (66.5%), hypothyroidism was (11.8%) and of hyperthyroidism was (21.7%). These percentages did not vary significantly with sex. (Author)

  20. The role of thyroid hormones in regulating of fatty acid spectrum of brain lipids: ontogenetic aspect

    Directory of Open Access Journals (Sweden)

    Rodynskiy A.G.

    2016-05-01

    Full Text Available In experiments on rats of three age groups the role of thyroid hormones in the regulation of fatty acid spectrum of cortical and hippocampus lipids was studied. It was found that on the background of decreased thyroid status content of polyunsaturated fractions of free fatty acids, significantly changed depending on the age of the animals. In particular, in juvenile rats hypothyroidism was accompanied by a decrease almost twice the number of pentacodan acid decreased lipids viscosity in neurocortex. In old rats reduce of pentacodan acid in the cortex (38% was supplemented by significant (77% decrease in linoleic and linolenic acids. Unlike the two age groups deficiency of thyroid hormones in young animals caused accumulation of free polyunsatarated fatty acids (C18: 2.3 in the cerebral cortex by 74%, which may be associated with a decrease of this fraction in fatty acid spectrum of lipids and increase of viscosity properties of the membranes. These restruc­turing may be associated with modulation of synaptic transmission of specific neurotransmitter systems in the brain.

  1. Thyroid hormone and the central control of homeostasis.

    Science.gov (United States)

    Warner, Amy; Mittag, Jens

    2012-08-01

    It has long been known that thyroid hormone has profound direct effects on metabolism and cardiovascular function. More recently, it was shown that the hormone also modulates these systems by actions on the central autonomic control. Recent studies that either manipulated thyroid hormone signalling in anatomical areas of the brain or analysed seasonal models with an endogenous fluctuation in hypothalamic thyroid hormone levels revealed that the hormone controls energy turnover. However, most of these studies did not progress beyond the level of anatomical nuclei; thus, the neuronal substrates as well as the molecular mechanisms remain largely enigmatic. This review summarises the evidence for a role of thyroid hormone in the central autonomic control of peripheral homeostasis and advocates novel strategies to address thyroid hormone action in the brain on a cellular level.

  2. Change of body height is regulated by thyroid hormone during metamorphosis in flatfishes and zebrafish.

    Science.gov (United States)

    Xu, Juan; Ke, Zhonghe; Xia, Jianhong; He, Fang; Bao, Baolong

    2016-09-15

    Flatfishes with more body height after metamorphosis should be better adapted to a benthic lifestyle. In this study, we quantified the changes in body height during metamorphosis in two flatfish species, Paralichthys olivaceus and Platichthys stellatus. The specific pattern of cell proliferation along the dorsal and ventral edge of the body to allow fast growth along the dorsal/ventral axis might be related to the change of body height. Thyroid hormone (T4 and T3) and its receptors showed distribution or gene expression patterns similar to those seen for the cell proliferation. 2-Mercapto-1-methylimidazole, an inhibitor of endogenous thyroid hormone synthesis, inhibited cell proliferation and decreased body height, suggesting that the change in body shape was dependent on the local concentration of thyroid hormone to induce cell proliferation. In addition, after treatment with 2-mercapto-1-methylimidazole, zebrafish larvae were also shown to develop a slimmer body shape. These findings enrich our knowledge of the role of thyroid hormone during flatfish metamorphosis, and the role of thyroid hormone during the change of body height during post-hatching development should help us to understand better the biology of metamorphosis in fishes. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Thyroid Hormone Signaling in the Mouse Retina.

    Directory of Open Access Journals (Sweden)

    Patrick Arbogast

    Full Text Available Thyroid hormone is a crucial regulator of gene expression in the developing and adult retina. Here we sought to map sites of thyroid hormone signaling at the cellular level using the transgenic FINDT3 reporter mouse model in which neurons express β-galactosidase (β-gal under the control of a hybrid Gal4-TRα receptor when triiodothyronine (T3 and cofactors of thyroid receptor signaling are present. In the adult retina, nearly all neurons of the ganglion cell layer (GCL, ganglion cells and displaced amacrine cells showed strong β-gal labeling. In the inner nuclear layer (INL, a minority of glycineric and GABAergic amacrine cells showed β-gal labeling, whereas the majority of amacrine cells were unlabeled. At the level of amacrine types, β-gal labeling was found in a large proportion of the glycinergic AII amacrines, but only in a small proportion of the cholinergic/GABAergic 'starburst' amacrines. At postnatal day 10, there also was a high density of strongly β-gal-labeled neurons in the GCL, but only few amacrine cells were labeled in the INL. There was no labeling of bipolar cells, horizontal cells and Müller glia cells at both stages. Most surprisingly, the photoreceptor somata in the outer nuclear layer also showed no β-gal label, although thyroid hormone is known to control cone opsin expression. This is the first record of thyroid hormone signaling in the inner retina of an adult mammal. We hypothesize that T3 levels in photoreceptors are below the detection threshold of the reporter system. The topographical distribution of β-gal-positive cells in the GCL follows the overall neuron distribution in that layer, with more T3-signaling cells in the ventral than the dorsal half-retina.

  4. Dependence of calcium on thyroid hormone for the regulation of ...

    African Journals Online (AJOL)

    concentration by mobilizing intracellular Ca2+. The mobilization of intracellular Ca2+in the absence of transmembrane Ca2+influx has been accepted as evidence for a cell-surface Ca2+ - receptor. The possible role of thyroid hormone in the ...

  5. Thyroid hormone and retinoic acid nuclear receptors: specific ligand-activated transcription factors

    International Nuclear Information System (INIS)

    Brtko, J.

    1998-01-01

    Transcriptional regulation by both the thyroid hormone and the vitamin A-derived 'retinoid hormones' is a critical component in controlling many aspects of higher vertebrate development and metabolism. Their functions are mediated by nuclear receptors, which comprise a large super-family of ligand-inducible transcription factors. Both the thyroid hormone and the retinoids are involved in a complex arrangement of physiological and development responses in many tissues of higher vertebrates. The functions of 3,5,3'-triiodothyronine (T 3 ), the thyromimetically active metabolite of thyroxine as well as all-trans retinoic acid, the biologically active vitamin A metabolite are mediated by nuclear receptor proteins that are members of the steroid/thyroid/retinoid hormone receptor family. The functions of all members of the receptor super family are discussed. (authors)

  6. Regulation of fatty acid composition and lipid storage by thyroid hormone in mouse liver

    OpenAIRE

    Yao, Xuan; Hou, Sarina; Zhang, Duo; Xia, Hongfeng; Wang, Yu-Cheng; Jiang, Jingjing; Yin, Huiyong; Ying, Hao

    2014-01-01

    Background Thyroid hormones (THs) are potent hormones modulating liver lipid homeostasis. The perturbation of lipid homeostasis is a hallmark of non-alcoholic fatty liver disease (NAFLD), a very common liver disorder. It was reported that NAFLD patients were associated with higher incidence of hypothyroidism. However, whether abnormal thyroid function contributes to the pathogenesis of NAFLD remains unclear. Results We used in vivo models to investigate the influence of hypothyroidism and TH ...

  7. Radioimmunoassay for thyroid-stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    Blakemore, J.I.; Lewin, N.; Burgett, M.W.

    1978-01-01

    This invention provides a method for the radioimmunoassay of thyroid-stimulating hormone which utilizes a rapid and convenient version of a double antibody procedure. Highly purified second antibody is bound, by means of covalent bonds, to hydrolyzed polyacrylamide particles to produce a two-phase system. The solid phase comprises immobilized second antibody bound to the reaction product of labeled and unlabeled thyroid-stimulating hormone with the first antibody (first antibody-antigen complex) and the liquid phase comprises free (unbound) labeled and unlabeled thyroid-stimulating hormone. The two phases are separated and the radioactivity of either phase is measured

  8. Pleiotropic Effects of Thyroid Hormones: Learning from Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Martha Franco

    2011-01-01

    Full Text Available Hypothyroidism induces several metabolic changes that allow understanding some physiopathological mechanisms. Under experimental hypothyroid conditions in rats, heart and kidney are protected against oxidative damage induced by ischemia reperfusion. An increased resistance to opening of the permeability transition pore seems to be at the basis of such protection. Moreover, glomerular filtration rate of hypothyroid kidney is low as a result of adenosine receptors-induced renal vasoconstriction. The vascular tone of aorta is also regulated by adenosine in hypothyroid conditions. In other context, thyroid hormones regulate lipoprotein metabolism. High plasma level of LDL cholesterol is a common feature in hypothyroidism, due to a low expression of the hepatic LDL receptor. In contrast, HDL-cholesterol plasma levels are variable in hypothyroidism; several proteins involved in HDL metabolism and structure are expressed at lower levels in experimental hypothyroidism. Based on the positive influence of thyroid hormones on lipoprotein metabolism, thyromimetic drugs are promising for the treatment of dyslipidemias. In summary, hypothyroid status has been useful to understand molecular mechanisms involved in ischemia reperfusion, regulation of vascular function and intravascular metabolism of lipoproteins.

  9. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    Energy Technology Data Exchange (ETDEWEB)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-05-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references.

  10. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    International Nuclear Information System (INIS)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-01-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references

  11. Thyroid hormone replacement therapy

    NARCIS (Netherlands)

    Wiersinga, W. M.

    2001-01-01

    Thyroid hormone replacement has been used for more than 100 years in the treatment of hypothyroidism, and there is no doubt about its overall efficacy. Desiccated thyroid contains both thyroxine (T(4)) and triiodothyronine (T(3)); serum T(3) frequently rises to supranormal values in the absorption

  12. Correlation of hormonal and cytokines regulation in case of autoimmune thyroiditis

    Directory of Open Access Journals (Sweden)

    Victoria V. Zdor

    2017-10-01

    Full Text Available Background. Studied immune aspects of the pathogenesis of autoimmune thyroiditis (AIT, which occupies the first place among human autoimmune pathologies. Treatment of the disease is based on thyroid hormones (TH replacement therapy. TH are today considered to be super antigens in autoimmune inflammation of the thyroid gland. Aims. On the basis of complex assessment of hormonal and immunological markers (TSH, TH, Treg, the Th1-, Th2-, Th17-marker cytokines with a research of possible interrelations of their indicators at patients with various clinical options of a current of AIT initially and against the background of replacement therapy of TH to define differences in functional activity of various types of immunocompetent cages depending on weight of inflammatory process for forecasting of a further clinical current of AIT, optimization of protocols of therapy and timely correction of strategy of treatment. Methods. In a prospective study, patients with AIT were evaluated for serum levels of cytokines and their receptors before initiating TH replacement therapy and on treatment by means of the ELISA modern methods with immuneсhemiluminescence and electroсhemiluminescence ways of detection. Results. Patients suffering from AIT showed an excess production of Th1-, Th2-, Th17- and Tregs marker cytokines with a deficiency of TGF-β1, closely connected with autoimmune hypothyroidism severity. Under pressure of TH therapy the indices of most cytokines decreased or improved, with the exception of IL-6, IL-8, IL-2, IFN-g, TNF-α. The greatest variations from the normal range were recorded in the complicated hypothyroidism. Conclusions. High serum TNF-α level in the onset of the disease is an important marker for the unfavourable AIT course and a predictor of hormone replacement therapy in case of its subclinical course. Safety indexes of functional thyroid epithelium are systemic levels of IL-8 and IL-22, their dynamic reduction in blood serum is an

  13. Thyroid profiles in a patient with resistance to thyroid hormone and episodes of thyrotoxicosis, including repeated painless thyroiditis.

    Science.gov (United States)

    Taniyama, Matsuo; Otsuka, Fumiko; Tozaki, Teruaki; Ban, Yoshiyuki

    2013-07-01

    Thyrotoxic disease can be difficult to recognize in patients with resistance to thyroid hormone (RTH) because the clinical symptoms of thyrotoxicosis cannot be observed, and thyrotropin (TSH) may not be suppressed because of hormone resistance. Painless thyroiditis is a relatively common cause of thyrotoxicosis, but its occurrence in RTH has not been reported. We assessed the thyroid profile in a patient with RTH and episodes of thyrotoxicosis who experienced repeated painless thyroiditis. A 44-year-old Japanese woman with RTH, which was confirmed by the presence of a P453A mutation in the thyroid hormone receptor β (TRβ) gene, showed a slight elevation of the basal levels of thyroid hormones, which indicated that her pituitary RTH was mild. She experienced a slight exacerbation of hyperthyroxinemia concomitant with TSH suppression. A diagnosis of painless thyroiditis was made because of the absence of TSH receptor antibodies, low Tc-99m pertechnetate uptake by the thyroid gland, and transient suppression followed by a slight elevation of TSH following the elevation of thyroid hormones. The patient's complaints of general malaise and occasional palpitations did not change throughout the course of painless thyroiditis. Three years later, painless thyroiditis occurred again without any deterioration of the clinical manifestations. Mild pituitary RTH can be overcome by slight exacerbation of hyperthyroxinemia during mild thyrotoxicosis. When pituitary resistance is severe and TSH is not suppressed, thyrotoxicosis may be overlooked.

  14. Hypothalamic mTOR pathway mediates thyroid hormone-induced hyperphagia in hyperthyroidism.

    Science.gov (United States)

    Varela, Luis; Martínez-Sánchez, Noelia; Gallego, Rosalía; Vázquez, María J; Roa, Juan; Gándara, Marina; Schoenmakers, Erik; Nogueiras, Rubén; Chatterjee, Krishna; Tena-Sempere, Manuel; Diéguez, Carlos; López, Miguel

    2012-06-01

    Hyperthyroidism is characterized in rats by increased energy expenditure and marked hyperphagia. Alterations of thermogenesis linked to hyperthyroidism are associated with dysregulation of hypothalamic AMPK and fatty acid metabolism; however, the central mechanisms mediating hyperthyroidism-induced hyperphagia remain largely unclear. Here, we demonstrate that hyperthyroid rats exhibit marked up-regulation of the hypothalamic mammalian target of rapamycin (mTOR) signalling pathway associated with increased mRNA levels of agouti-related protein (AgRP) and neuropeptide Y (NPY), and decreased mRNA levels of pro-opiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC), an area where mTOR co-localizes with thyroid hormone receptor-α (TRα). Central administration of thyroid hormone (T3) or genetic activation of thyroid hormone signalling in the ARC recapitulated hyperthyroidism effects on feeding and the mTOR pathway. In turn, central inhibition of mTOR signalling with rapamycin in hyperthyroid rats reversed hyperphagia and normalized the expression of ARC-derived neuropeptides, resulting in substantial body weight loss. The data indicate that in the hyperthyroid state, increased feeding is associated with thyroid hormone-induced up-regulation of mTOR signalling. Furthermore, our findings that different neuronal modulations influence food intake and energy expenditure in hyperthyroidism pave the way for a more rational design of specific and selective therapeutic compounds aimed at reversing the metabolic consequences of this disease. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  15. Thyroid hormone increases fibroblast growth factor receptor expression and disrupts cell mechanics in the developing organ of corti

    Science.gov (United States)

    2013-01-01

    Background Thyroid hormones regulate growth and development. However, the molecular mechanisms by which thyroid hormone regulates cell structural development are not fully understood. The mammalian cochlea is an intriguing system to examine these mechanisms, as cellular structure plays a key role in tissue development, and thyroid hormone is required for the maturation of the cochlea in the first postnatal week. Results In hypothyroid conditions, we found disruptions in sensory outer hair cell morphology and fewer microtubules in non-sensory supporting pillar cells. To test the functional consequences of these cytoskeletal defects on cell mechanics, we combined atomic force microscopy with live cell imaging. Hypothyroidism stiffened outer hair cells and supporting pillar cells, but pillar cells ultimately showed reduced cell stiffness, in part from a lack of microtubules. Analyses of changes in transcription and protein phosphorylation suggest that hypothyroidism prolonged expression of fibroblast growth factor receptors, and decreased phosphorylated Cofilin. Conclusions These findings demonstrate that thyroid hormones may be involved in coordinating the processes that regulate cytoskeletal dynamics and suggest that manipulating thyroid hormone sensitivity might provide insight into the relationship between cytoskeletal formation and developing cell mechanical properties. PMID:23394545

  16. Recent Advances in Thyroid Hormone Regulation: Toward a New Paradigm for Optimal Diagnosis and Treatment

    Science.gov (United States)

    Hoermann, Rudolf; Midgley, John E. M.; Larisch, Rolf; Dietrich, Johannes W.

    2017-01-01

    In thyroid health, the pituitary hormone thyroid-stimulating hormone (TSH) raises glandular thyroid hormone production to a physiological level and enhances formation and conversion of T4 to the biologically more active T3. Overstimulation is limited by negative feedback control. In equilibrium defining the euthyroid state, the relationship between TSH and FT4 expresses clusters of genetically determined, interlocked TSH–FT4 pairs, which invalidates their statistical correlation within the euthyroid range. Appropriate reactions to internal or external challenges are defined by unique solutions and homeostatic equilibria. Permissible variations in an individual are much more closely constrained than over a population. Current diagnostic definitions of subclinical thyroid dysfunction are laboratory based, and do not concur with treatment recommendations. An appropriate TSH level is a homeostatic concept that cannot be reduced to a fixed range consideration. The control mode may shift from feedback to tracking where TSH becomes positively, rather than inversely related with FT4. This is obvious in pituitary disease and severe non-thyroid illness, but extends to other prevalent conditions including aging, obesity, and levothyroxine (LT4) treatment. Treatment targets must both be individualized and respect altered equilibria on LT4. To avoid amalgamation bias, clinically meaningful stratification is required in epidemiological studies. In conclusion, pituitary TSH cannot be readily interpreted as a sensitive mirror image of thyroid function because the negative TSH–FT4 correlation is frequently broken, even inverted, by common conditions. The interrelationships between TSH and thyroid hormones and the interlocking elements of the control system are individual, dynamic, and adaptive. This demands a paradigm shift of its diagnostic use. PMID:29375474

  17. Recent Advances in Thyroid Hormone Regulation: Toward a New Paradigm for Optimal Diagnosis and Treatment

    Directory of Open Access Journals (Sweden)

    Rudolf Hoermann

    2017-12-01

    Full Text Available In thyroid health, the pituitary hormone thyroid-stimulating hormone (TSH raises glandular thyroid hormone production to a physiological level and enhances formation and conversion of T4 to the biologically more active T3. Overstimulation is limited by negative feedback control. In equilibrium defining the euthyroid state, the relationship between TSH and FT4 expresses clusters of genetically determined, interlocked TSH–FT4 pairs, which invalidates their statistical correlation within the euthyroid range. Appropriate reactions to internal or external challenges are defined by unique solutions and homeostatic equilibria. Permissible variations in an individual are much more closely constrained than over a population. Current diagnostic definitions of subclinical thyroid dysfunction are laboratory based, and do not concur with treatment recommendations. An appropriate TSH level is a homeostatic concept that cannot be reduced to a fixed range consideration. The control mode may shift from feedback to tracking where TSH becomes positively, rather than inversely related with FT4. This is obvious in pituitary disease and severe non-thyroid illness, but extends to other prevalent conditions including aging, obesity, and levothyroxine (LT4 treatment. Treatment targets must both be individualized and respect altered equilibria on LT4. To avoid amalgamation bias, clinically meaningful stratification is required in epidemiological studies. In conclusion, pituitary TSH cannot be readily interpreted as a sensitive mirror image of thyroid function because the negative TSH–FT4 correlation is frequently broken, even inverted, by common conditions. The interrelationships between TSH and thyroid hormones and the interlocking elements of the control system are individual, dynamic, and adaptive. This demands a paradigm shift of its diagnostic use.

  18. The determination of thyroid hormone autoantibodies and its clinical significance

    International Nuclear Information System (INIS)

    Zhu Li; Zhao Zhiying; Wang Zhenghua Lian Xiaolan; Guo Zhisheng; Bai Yao; Su Wei

    2003-01-01

    To study the reasons of falsely high concentrations of serum thyroid hormone and the way of determination of thyroid hormone autoantibodies, the experiments of thyroid hormone autoantibodies binding reaction, dilution testing, calibration curves and their check analysis were performed. Results showed that the combination of the autoantibodies with 125 I-T 3 or 125 I-T 4 was specific, the binding rates were 58.77% and 49.05% respectively and 7-12 times higher than control groups. The radioactive peaks of the autoantibodies and rabbit anti-T 3 or T 4 antibody appeared on the same position in radio electrophoretogram analysis and these antibodies were considered as IgG. The important reasons of falsely high concentrations of serum thyroid hormone are the presence of anti-thyroid hormone antibodies. Determination of thyroid hormone autoantibodies significantly benefits diagnosis and treatment of thyroid disease

  19. Functional neuroanatomy of thyroid hormone feedback in the human hypothalamus and pituitary gland

    NARCIS (Netherlands)

    Fliers, Eric; Unmehopa, Unga A.; Alkemade, Anneke

    2006-01-01

    A major change in thyroid setpoint regulation occurs in various clinical conditions such as critical illness and psychiatric disorders. As a first step towards identifying determinants of these setpoint changes, we have studied the distribution and expression of thyroid hormone receptor (TR)

  20. Thyroid Hormone Receptor Beta in the Ventromedial Hypothalamus Is Essential for the Physiological Regulation of Food Intake and Body Weight

    Directory of Open Access Journals (Sweden)

    Saira Hameed

    2017-06-01

    Full Text Available The obesity epidemic is a significant global health issue. Improved understanding of the mechanisms that regulate appetite and body weight will provide the rationale for the design of anti-obesity therapies. Thyroid hormones play a key role in metabolic homeostasis through their interaction with thyroid hormone receptors (TRs, which function as ligand-inducible transcription factors. The TR-beta isoform (TRβ is expressed in the ventromedial hypothalamus (VMH, a brain area important for control of energy homeostasis. Here, we report that selective knockdown of TRβ in the VMH of adult mice results in severe obesity due to hyperphagia and reduced energy expenditure. The observed increase in body weight is of a similar magnitude to murine models of the most extreme forms of monogenic obesity. These data identify TRβ in the VMH as a major physiological regulator of food intake and energy homeostasis.

  1. Studies on the regulation of anuran metamorphosis by thyroid hormones and prolactin

    International Nuclear Information System (INIS)

    Ray, L.B.

    1985-01-01

    Resorption of the tail of the anuran larva during metamorphosis is induced by the thyroid hormones. In contrast, the pituitary hormone prolactin favors growth of the tail fin and inhibits resorption. The present investigations were designed to explore the mechanisms by which the thyroid hormones and prolactin bring about their cellular effects. Incubation of explants of tail fin with derivatives of cAMP was shown to inhibit T 4 -induced resorption of explants in a manner similar to that of prolactin. Likewise, inhibition of phosphodiesterases also inhibited resorption. Prolactin, however, failed to alter the levels of cAMP in cultured explants of tail fin. Although cAMP antagonizes the resorptive effects of T 4 , prolactin apparently does not act by elevating cellular levels of that cyclic nucleotide. Newly synthesized proteins from explants of tail fin were examined by isotopical labeling followed by two-dimensional gel electrophoresis and fluorography. Incorporation of 35 S-methionine into four proteins was increased within 8 to 48 hours after exposure of explants to T 4 . Three of the same proteins appeared to be synthesized more rapidly in explants of fin from tadpoles at metamorphic climax than in fin from tadpoles of premetamorphic stages. These results indicate that treatment of explants with T 4 or elevation of endogenous levels of thyroid hormones during spontaneous metamorphosis increased the relative rates of synthesis of several proteins. Those proteins are potentially involved in initiating the effects of T 4 which lead to cell death and resorption of the tail

  2. Sterol regulatory element-binding proteins are regulators of the rat thyroid peroxidase gene in thyroid cells.

    Directory of Open Access Journals (Sweden)

    Christine Rauer

    Full Text Available Sterol regulatory element-binding proteins (SREBPs-1c and -2, which were initially discovered as master transcriptional regulators of lipid biosynthesis and uptake, were recently identified as novel transcriptional regulators of the sodium-iodide symporter gene in the thyroid, which is essential for thyroid hormone synthesis. Based on this observation that SREBPs play a role for thyroid hormone synthesis, we hypothesized that another gene involved in thyroid hormone synthesis, the thyroid peroxidase (TPO gene, is also a target of SREBP-1c and -2. Thyroid epithelial cells treated with 25-hydroxycholesterol, which is known to inhibit SREBP activation, had about 50% decreased mRNA levels of TPO. Similarly, the mRNA level of TPO was reduced by about 50% in response to siRNA mediated knockdown of both, SREBP-1 and SREBP-2. Reporter gene assays revealed that overexpression of active SREBP-1c and -2 causes a strong transcriptional activation of the rat TPO gene, which was localized to an approximately 80 bp region in the intron 1 of the rat TPO gene. In vitro- and in vivo-binding of both, SREBP-1c and SREBP-2, to this region in the rat TPO gene could be demonstrated using gel-shift assays and chromatin immunoprecipitation. Mutation analysis of the 80 bp region of rat TPO intron 1 revealed two isolated and two overlapping SREBP-binding elements from which one, the overlapping SRE+609/InvSRE+614, was shown to be functional in reporter gene assays. In connection with recent findings that the rat NIS gene is also a SREBP target gene in the thyroid, the present findings suggest that SREBPs may be possible novel targets for pharmacological modulation of thyroid hormone synthesis.

  3. Challenges in interpretation of thyroid hormone test results

    Directory of Open Access Journals (Sweden)

    Lalić Tijana

    2016-01-01

    Full Text Available Introduction. In interpreting thyroid hormones results it is preferable to think of interference and changes in concentration of their carrier proteins. Outline of Cases. We present two patients with discrepancy between the results of thyroid function tests and clinical status. The first case presents a 62-year-old patient with a nodular goiter and Hashimoto thyroiditis. Thyroid function test showed low thyroid-stimulating hormone (TSH and normal to low fT4. By determining thyroid status (ТSH, T4, fT4, T3, fT3 in two laboratories, basal and after dilution, as well as thyroxine-binding globulin (TBG, it was concluded that the thyroid hormone levels were normal. The results were influenced by heterophile antibodies leading to a false lower TSH level and suspected secondary hypothyroidism. The second case, a 40-year-old patient, was examined and followed because of the variable size thyroid nodule and initially borderline elevated TSH, after which thyroid status showed low level of total thyroid hormones and normal TSH. Based on additional analysis it was concluded that low T4 and T3 were a result of low TBG. It is a hereditary genetic disorder with no clinical significance. Conclusion. Erroneous diagnosis of thyroid disorders and potentially harmful treatment could be avoided by proving the interference or TBG deficiency whenever there is a discrepancy between the thyroid function results and the clinical picture.

  4. Thyroid hormone action: Astrocyte-neuron communication.

    Directory of Open Access Journals (Sweden)

    Beatriz eMorte

    2014-05-01

    Full Text Available Thyroid hormone action is exerted mainly through regulation of gene expression by binding of T3 to the nuclear receptors. T4 plays an important role as a source of intracellular T3 in the central nervous system via the action of the type 2 deiodinase, expressed in the astrocytes. A model of T3 availability to neural cells has been proposed and validated. The model contemplates that brain T3 has a double origin: a fraction is available directly from the circulation, and another is produced locally from T4 in the astrocytes by type 2 deiodinase. The fetal brain depends almost entirely on the T3 generated locally. The contribution of systemic T3 increases subsequently during development to account for approximately 50% of total brain T3 in the late postnatal and adult stages. In this article we review the experimental data in support of this model, and how the factors affecting T3 availability in the brain, such as deiodinases and transporters, play a decisive role in modulating local thyroid hormone action during development.

  5. Illness-induced changes in thyroid hormone metabolism: focus on the tissue level

    NARCIS (Netherlands)

    Kwakkel, J.; Fliers, E.; Boelen, A.

    2011-01-01

    During illness changes in thyroid hormone metabolism occur, collectively known as the non-thyroidal illness syndrome (NTIS). NTIS is characterised by low serum thyroid hormone levels without the expected rise in serum thyroid-stimulating hormone, indicating a major change in thyroid hormone feedback

  6. Not all elevated hormones are toxic: A case of thyroid hormone resistance

    Directory of Open Access Journals (Sweden)

    Rajeev Philip

    2016-01-01

    Full Text Available Resistance to thyroid hormone syndrome (RTH is a rare disorder and is usually inherited as dominantly negative autosomal trait. RTH is caused by mutations in the thyroid hormone receptor beta. Patients with RTH usually do not have signs and symptoms of thyrotoxicosis, but the thyroid function test shows an elevated T3 and T4, which get misinterpreted as hyperthyroidism, resulting in unnecessary treatment.

  7. Thyroid-stimulating hormone pituitary adenomas.

    Science.gov (United States)

    Clarke, Michelle J; Erickson, Dana; Castro, M Regina; Atkinson, John L D

    2008-07-01

    Thyroid-stimulating hormone (TSH)-secreting pituitary adenomas are rare, representing secreting or clinically silent TSH-immunostaining pituitary tumors among all pituitary adenomas followed at their institution between 1987 and 2003. Patient records, including clinical, imaging, and pathological and surgical characteristics were reviewed. Twenty-one patients (6 women and 15 men; mean age 46 years, range 26-73 years) were identified. Of these, 10 patients had a history of clinical hyperthyroidism, of whom 7 had undergone ablative thyroid procedures (thyroid surgery/(131)I ablation) prior to the diagnosis of pituitary adenoma. Ten patients had elevated TSH preoperatively. Seven patients presented with headache, and 8 presented with visual field defects. All patients underwent imaging, of which 19 were available for imaging review. Sixteen patients had macroadenomas. Of the 21 patients, 18 underwent transsphenoidal surgery at the authors' institution, 2 patients underwent transsphenoidal surgery at another facility, and 1 was treated medically. Patients with TSH-secreting tumors were defined as in remission after surgery if they had no residual adenoma on imaging and had biochemical evidence of hypo-or euthyroidism. Patients with TSH-immunostaining tumors were considered in remission if they had no residual tumor. Of these 18 patients, 9 (50%) were in remission following surgery. Seven patients had residual tumor; 2 of these patients underwent further transsphenoidal resection, 1 underwent a craniotomy, and 4 underwent postoperative radiation therapy (2 conventional radiation therapy, 1 Gamma Knife surgery, and 1 had both types of radiation treatment). Two patients had persistently elevated TSH levels despite the lack of evidence of residual tumor. On pathological analysis and immunostaining of the surgical specimen, 17 patients had samples that stained positively for TSH, 8 for alpha-subunit, 10 for growth hormone, 7 for prolactin, 2 for adrenocorticotrophic hormone

  8. Amiodarone: Effects on thyroid function and the peripheral metabolism of the thyroid hormones

    International Nuclear Information System (INIS)

    Braverman, L.E.; Safran, M.; Bambini, G.; Pinchera, A.; Martino, E.

    1985-01-01

    In addition to the effects of Amiodarone on the peripheral metabolism of the thyroid hormones and on pituitary TSH secretion, a major complication of therapy is the relatively high frequency of iodide-induced thyroid dysfunction. The mean T 4 and T 3 concentration following Amiodarone application was measured in euthyroid, hypothyroid and hyperthyroid patients and in control patients with and without cardiac disorders. Furthermore, the serum TSH was determined in euthyroid Amiodarone-treated euthyroid patients. 131 I uptake was studied in patients with Amiodarone-associated thyrotoxicosis. The difficulties of the therapy of Amiodarone-induced hyper-thyroidism are outlined. Preliminary studied of the effect of Amiodarone and its analogues on the metabolism of thyroid hormones in the rat indicate that Amiodarone may act as a thyroid hormone agonist in the pituitary. (MG)

  9. Thyroid hormones and the central nervous system of mammals (Review).

    Science.gov (United States)

    Di Liegro, Italia

    2008-01-01

    The thyroid hormones (THs) L-thyroxine (T4) and L-triiodothyronine (T3) have a profound influence on the development and maturation of the mammalian brain, both before and after birth. Any impairment in the supply of THs to the developing nervous system leads to severe and irreversible changes in both the overall architecture and functions of the brain and causes, in humans, neurological and motor deficits known as cretinism. Pronounced neurological symptoms are also commonly observed in adult patients suffering from both hyperthyroidism and hypothyroidism, and it has recently emerged that certain symptoms might result from the reduced brain uptake, rather than the insufficient production, of THs. Most of the effects of THs are mediated by two classes of nuclear receptors (α and β isoforms), which belong to the c-erbA superfamily of transcriptional regulators and are expressed in a tissue-specific and developmentally regulated manner. Interestingly, the nuclear TH receptors (nTRs) act as both ligand-independent gene repressors and ligand-dependent gene activators. On the other hand, negatively-regulated genes, which can be stimulated in the absence of THs and repressed by THs, have also been observed. Due to this complex pattern of regulation, the effects of receptor dysfunction do not exactly overlap the effects of hormone deficiency or excess. Moreover, non-genomic mechanisms of TH action have been described in many tissues, including the brain, some of which seem to be mediated by integrins and to be calcium-dependent. Intracellular receptors, distinct from nTRs, are present in the mitochondria, where a matrix-associated, T3-dependent transcriptional regulator of approximately 43 kDa has been described. Finally, complex patterns of pituitary and/or peripheral resistance to thyroid hormones (RTH), characterized by elevated plasma levels of THs and non-suppressible thyroid-stimulating hormone (TSH), have been identified. This review summarizes the major advances

  10. Desethylamiodarone is a competitive inhibitor of the binding of thyroid hormone to the thyroid hormone alpha 1-receptor protein

    NARCIS (Netherlands)

    van Beeren, H. C.; Bakker, O.; Wiersinga, W. M.

    1995-01-01

    Desethylamiodarone (DEA), the major metabolite of the potent antiarrythmic drug amiodarone, is a non-competitive inhibitor of the binding of thyroid hormone (T3) to the beta 1-thyroid hormone receptor (T3R). In the present study, we investigated whether DEA acts in a similar way with respect to the

  11. Thyroid hormones upregulate apolipoprotein E gene expression in astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Corina; Fuior, Elena V.; Trusca, Violeta G. [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania); Kardassis, Dimitris [University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, Crete (Greece); Simionescu, Maya [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania); Gafencu, Anca V., E-mail: anca.gafencu@icbp.ro [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania)

    2015-12-04

    Apolipoprotein E (apoE), a protein mainly involved in lipid metabolism, is associated with several neurodegenerative disorders including Alzheimer's disease. Despite numerous attempts to elucidate apoE gene regulation in the brain, the exact mechanism is still uncovered. The mechanism of apoE gene regulation in the brain involves the proximal promoter and multienhancers ME.1 and ME.2, which evolved by gene duplication. Herein we questioned whether thyroid hormones and their nuclear receptors have a role in apoE gene regulation in astrocytes. Our data showed that thyroid hormones increase apoE gene expression in HTB14 astrocytes in a dose-dependent manner. This effect can be intermediated by the thyroid receptor β (TRβ) which is expressed in these cells. In the presence of triiodothyronine (T3) and 9-cis retinoic acid, in astrocytes transfected to overexpress TRβ and retinoid X receptor α (RXRα), apoE promoter was indirectly activated through the interaction with ME.2. To determine the location of TRβ/RXRα binding site on ME.2, we performed DNA pull down assays and found that TRβ/RXRα complex bound to the region 341–488 of ME.2. This result was confirmed by transient transfection experiments in which a series of 5′- and 3′-deletion mutants of ME.2 were used. These data support the existence of a biologically active TRβ binding site starting at 409 in ME.2. In conclusion, our data revealed that ligand-activated TRβ/RXRα heterodimers bind with high efficiency on tissue-specific distal regulatory element ME.2 and thus modulate apoE gene expression in the brain. - Highlights: • T3 induce a dose-dependent increase of apoE expression in astrocytes. • Thyroid hormones activate apoE promoter in a cell specific manner. • Ligand activated TRβ/RXRα bind on the distal regulatory element ME.2 to modulate apoE. • The binding site of TRβ/RXRα heterodimer is located at 409 bp on ME.2.

  12. Thyroid hormones upregulate apolipoprotein E gene expression in astrocytes

    International Nuclear Information System (INIS)

    Roman, Corina; Fuior, Elena V.; Trusca, Violeta G.; Kardassis, Dimitris; Simionescu, Maya; Gafencu, Anca V.

    2015-01-01

    Apolipoprotein E (apoE), a protein mainly involved in lipid metabolism, is associated with several neurodegenerative disorders including Alzheimer's disease. Despite numerous attempts to elucidate apoE gene regulation in the brain, the exact mechanism is still uncovered. The mechanism of apoE gene regulation in the brain involves the proximal promoter and multienhancers ME.1 and ME.2, which evolved by gene duplication. Herein we questioned whether thyroid hormones and their nuclear receptors have a role in apoE gene regulation in astrocytes. Our data showed that thyroid hormones increase apoE gene expression in HTB14 astrocytes in a dose-dependent manner. This effect can be intermediated by the thyroid receptor β (TRβ) which is expressed in these cells. In the presence of triiodothyronine (T3) and 9-cis retinoic acid, in astrocytes transfected to overexpress TRβ and retinoid X receptor α (RXRα), apoE promoter was indirectly activated through the interaction with ME.2. To determine the location of TRβ/RXRα binding site on ME.2, we performed DNA pull down assays and found that TRβ/RXRα complex bound to the region 341–488 of ME.2. This result was confirmed by transient transfection experiments in which a series of 5′- and 3′-deletion mutants of ME.2 were used. These data support the existence of a biologically active TRβ binding site starting at 409 in ME.2. In conclusion, our data revealed that ligand-activated TRβ/RXRα heterodimers bind with high efficiency on tissue-specific distal regulatory element ME.2 and thus modulate apoE gene expression in the brain. - Highlights: • T3 induce a dose-dependent increase of apoE expression in astrocytes. • Thyroid hormones activate apoE promoter in a cell specific manner. • Ligand activated TRβ/RXRα bind on the distal regulatory element ME.2 to modulate apoE. • The binding site of TRβ/RXRα heterodimer is located at 409 bp on ME.2.

  13. Thyroid Hormone Availability and Action during Brain Development in Rodents

    OpenAIRE

    Soledad Bárez-López; Soledad Bárez-López; Ana Guadaño-Ferraz; Ana Guadaño-Ferraz

    2017-01-01

    Thyroid hormones (THs) play an essential role in the development of all vertebrates; in particular adequate TH content is crucial for proper neurodevelopment. TH availability and action in the brain are precisely regulated by several mechanisms, including the secretion of THs by the thyroid gland, the transport of THs to the brain and neural cells, THs activation and inactivation by the metabolic enzymes deiodinases and, in the fetus, transplacental passage of maternal THs. Although these mec...

  14. Endocrine determinants of haemostasis and thrombosis risk: Focus on thyroid hormone

    NARCIS (Netherlands)

    Elbers, L.P.B.

    2016-01-01

    This thesis explores endocrine determinants of the haemostatic system and thrombosis risk with main focus on thyroid hormone. It describes, in three parts, the effects of thyroid hormone on the haemostatic system, the effects of thyroid hormone (mimetics) on lipids and the effects of other hormones

  15. Neuroanatomical pathways for thyroid hormone feedback in the human hypothalamus

    NARCIS (Netherlands)

    Alkemade, Anneke; Friesema, Edith C.; Unmehopa, Unga A.; Fabriek, Babs O.; Kuiper, George G.; Leonard, Jack L.; Wiersinga, Wilmar M.; Swaab, Dick F.; Visser, Theo J.; Fliers, Eric

    2005-01-01

    Context: Recent findings point to an increasing number of hypothalamic proteins involved in the central regulation of thyroid hormone feedback. The functional neuroanatomy of these proteins in the human hypothalamus is largely unknown at present. Objective: The aim of this study was to report the

  16. Imbalance between thyroid hormones and the dopaminergic system might be central to the pathophysiology of restless legs syndrome: a hypothesis

    Directory of Open Access Journals (Sweden)

    Jose Carlos Pereira Jr.

    2010-01-01

    Full Text Available Data collected from medical literature indicate that dopaminergic agonists alleviate Restless Legs Syndrome symptoms while dopaminergic agonists antagonists aggravate them. Dopaminergic agonists is a physiological regulator of thyroid-stimulating hormone. Dopaminergic agonists infusion diminishes the levels of thyroid hormones, which have the ability to provoke restlessness, hyperkinetic states, tremors, and insomnia. Conditions associated with higher levels of thyroid hormones, such as pregnancy or hyperthyroidism, have a higher prevalence of Restless Legs Syndrome symptoms. Low iron levels can cause secondary Restless Legs Syndrome or aggravate symptoms of primary disease as well as diminish enzymatic activities that are involved in dopaminergic agonists production and the degradation of thyroid hormones. Moreover, as a result of low iron levels, dopaminergic agonists diminishes and thyroid hormones increase. Iron therapy improves Restless Legs Syndrome symptoms in iron deprived patients. Medical hypothesis. To discuss the theory that thyroid hormones, when not counterbalanced by dopaminergic agonists, may precipitate the signs and symptoms underpinning Restless Legs Syndrome. The main cause of Restless Legs Syndrome might be an imbalance between the dopaminergic agonists system and thyroid hormones.

  17. Mechanism-based testing strategy using in vitro approaches for identification of thyroid hormone disrupting chemicals

    NARCIS (Netherlands)

    Murk, A.J.; Rijntjes, E.; Blaauboer, B.J.; Clewell, R.; Crofton, K.M.; Dingemans, M.M.L.; Furlow, J.D.; Kavlock, R.; Kohrle, J.; Opitz, R.; Traas, T.; Visser, T.J.; Xia, M.; Gutleb, A.C.

    2013-01-01

    The thyroid hormone (TH) system is involved in several important physiological processes, including regulation of energy metabolism, growth and differentiation, development and maintenance of brain function, thermo-regulation, osmo-regulation, and axis of regulation of other endocrine systems,

  18. The interrelationships of thyroid and growth hormones: effect of growth hormone releasing hormone in hypo- and hyperthyroid male rats.

    Science.gov (United States)

    Root, A W; Shulman, D; Root, J; Diamond, F

    1986-01-01

    Growth hormone (GH) and the thyroid hormones interact in the hypothalamus, pituitary and peripheral tissues. Thyroid hormone exerts a permissive effect upon the anabolic and metabolic effects of GH, and increases pituitary synthesis of this protein hormone. GH depresses the secretion of thyrotropin and the thyroid hormones and increases the peripheral conversion of thyroxine to triiodothyronine. In the adult male rat experimental hypothyroidism produced by ingestion of propylthiouracil depresses the GH secretory response to GH-releasing hormone in vivo and in vitro, reflecting the lowered pituitary stores of GH in the hypothyroid state. Short term administration of large amounts of thyroxine with induction of the hyperthyroid state does not affect the in vivo GH secretory response to GH-releasing hormone in this animal.

  19. Disruption of thyroid hormone functions by low dose exposure of tributyltin: an in vitro and in vivo approach.

    Science.gov (United States)

    Sharan, Shruti; Nikhil, Kumar; Roy, Partha

    2014-09-15

    Triorganotins, such as tributyltin chloride (TBTCl), are environmental contaminants that are commonly found in the antifouling paints used in ships and other vessels. The importance of TBTCl as an endocrine-disrupting chemical (EDC) in different animal models is well known; however, its adverse effects on the thyroid gland are less understood. Hence, in the present study, we aimed to evaluate the thyroid-disrupting effects of this chemical using both in vitro and in vivo approaches. We used HepG2 hepatocarcinoma cells for the in vitro studies, as they are a thyroid hormone receptor (TR)-positive and thyroid responsive cell line. For the in vivo studies, Swiss albino male mice were exposed to three doses of TBTCl (0.5, 5 and 50μg/kg/day) for 45days. TBTCl showed a hypo-thyroidal effect in vivo. Low-dose treatment of TBTCl exposure markedly decreased the serum thyroid hormone levels via the down-regulation of the thyroid peroxidase (TPO) and thyroglobulin (Tg) genes by 40% and 25%, respectively, while augmenting the thyroid stimulating hormone (TSH) levels. Thyroid-stimulating hormone receptor (TSHR) expression was up-regulated in the thyroid glands of treated mice by 6.6-fold relative to vehicle-treated mice (p<0.05). In the transient transactivation assays, TBTCl suppressed T3 mediated transcriptional activity in a dose-dependent manner. In addition, TBTCl was found to decrease the expression of TR. The present study thus indicates that low concentrations of TBTCl suppress TR transcription by disrupting the physiological concentrations of T3/T4, followed by the recruitment of NCoR to TR, providing a novel insight into the thyroid hormone-disrupting effects of this chemical. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Thyroid hormones and adult-type Leydig cell development

    NARCIS (Netherlands)

    Rijntjes, E.

    2008-01-01

    Alterations in thyroid hormone levels are well known to influence key functions in growth and development. Although in many countries the diet is fortified with iodide, essential for thyroid hormone synthesis, still not all humans have access to fortified diets, leaving a substantial part of the

  1. Thyroid hormone resistance may course hypotonia in infancy

    DEFF Research Database (Denmark)

    Pivkovska, Julijana; Born, Alfred Peter; Nielsen, Claus Thøger

    2014-01-01

    Allan Herndon Dudley's syndrome (AHDS) is X-linked mental retardation and hypotonia caused by mutations in a thyroid hormone transporter gene - MCT8. The typical thyreoidea AHDS profile is elevated T3, low-normal T4 and normal or elevated thyroid stimulating hormone (TSH). Neonatal screening...

  2. The thyroid hormone triiodothyronine controls macrophage maturation and functions: protective role during inflammation.

    Science.gov (United States)

    Perrotta, Cristiana; Buldorini, Marcella; Assi, Emma; Cazzato, Denise; De Palma, Clara; Clementi, Emilio; Cervia, Davide

    2014-01-01

    The endocrine system participates in regulating macrophage maturation, although little is known about the modulating role of the thyroid hormones. In vitro results demonstrate a negative role of one such hormone, triiodothyronine (T3), in triggering the differentiation of bone marrow-derived monocytes into unpolarized macrophages. T3-induced macrophages displayed a classically activated (M1) signature. A T3-induced M1-priming effect was also observed on polarized macrophages because T3 reverses alternatively activated (M2) activation, whereas it enhances that of M1 cells. In vivo, circulating T3 increased the content of the resident macrophages in the peritoneal cavity, whereas it reduced the content of the recruited monocyte-derived cells. Of interest, T3 significantly protected mice against endotoxemia induced by lipopolysaccharide i.p. injection; in these damaged animals, decreased T3 levels increased the recruited (potentially damaging) cells, whereas restoring T3 levels decreased recruited and increased resident (potentially beneficial) cells. These data suggest that the anti-inflammatory effect of T3 is coupled to the modulation of peritoneal macrophage content, in a context not fully explained by the M1/M2 framework. Thyroid hormone receptor expression analysis and the use of different thyroid hormone receptor antagonists suggest thyroid hormone receptor β1 as the major player mediating T3 effects on macrophages. The novel homeostatic link between thyroid hormones and the pathophysiological role of macrophages opens new perspectives on the interactions between the endocrine and immune systems. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. Action of the schistosomotic spleen in male mices on the regulation of thyroid hormones

    International Nuclear Information System (INIS)

    Neves, S.R.S.; Silva, I.M.S.; Pereira, S.S.L.; Lima Filho, G.L.; Catanho, M.T.J.A.; Neves, E.S.; Silveira, M.F.G.

    1997-01-01

    For the purpose to study the action of the schistosomotic spleen on the regulation of TSH, T4 and albumin levels in serum, spleens from adults mice infected by Schistosoma mansoni were homogeneized, centrifuged and cromatographed in a column of Sephadex G-100, resulting in two proteans fractions (I and II). The biologic activity was determinated through the administration of the fractions by intraperitoneal way (IP), in male mice aged 27-30 days, in a period of three following days. Five days after the last administration, the animals were sacrified and their blood was collected for obtainment of serum and determination of TSH, T4 and albumin levels. Obtained results showed that the albumin levels no change when compared to control and that fraction I infected change the TSH and T4 levels, but the fraction II infected no change this levels. These results suggest that spleens from mice infected by S. mansoni have a factor that modifies the hormonal regulation in level hypophysial and the synthesis of thyroid hormones (T4), changing the basal metabolism. The seric levels of TSH and T4 were determined by radioimmunoassay using I-125. (author). 12 refs., 1 tab

  4. Thyroid hormone radioimmunoassay

    International Nuclear Information System (INIS)

    Rodriguez, S.; Richmond, M.; Quesada, S.; Lahaman, S.; Ramirez, A.; Herrera, J.F.

    1988-01-01

    The International Atomic Energy Agency (AIEA) is carrying out the ARCAL VIII Program 'Thiroid Hormone Readioimmunoassay'. The Immunoassay Laboratory of INCIENSA is in charge of this program, with the participation of four National Hospital System laboratories, which carried out Thyroxine (T4). Triodothyroxine (T3) and Thyroid Stimulating Hormone (TSH) assays with NETRIA Reagents (North East Thames Region Immunoassay Unit). The variability was shown to be between 9-20 per cent for T4, 12-22 per cent for TSH and 22-36 per cent for T3. The study also evaluated the quality of a tracer (T3-l125 and T4 l125) produced at INCIENSA. In this case the intrassay variability was 8,4 per cent for T3 and 6,8 per cent for T4 in 32 determinations evaluated during 6 months. It was concluded that the T4 and TSH tests but not the T3 test are valid and reproducible when NETRIA Ragents are used. The tracer made at INCIENSA can be used up to 6 weeks after the radioiodination with l125. A successful thyroid-related hormones quality control was defined in Costa Rica by taking advantage of the support of a prestigious international agency, the IAEA. (author). 13 refs, 4 figs

  5. Functional analysis of novel genetic variation in the thyroid hormone activating type 2 deiodinase

    NARCIS (Netherlands)

    C. Zevenbergen (Chantal); W. Klootwijk (Willem); R.P. Peeters (Robin); M. Medici (Marco); Y.B. de Rijke (Yolanda); S.A. Huisman (Sylvia); Goeman, H. (Henk); Boot, E. (Erik); G. Kuijper (Gerda); K.H. de Waal; M.E. Meima (Marcel); P.R. Larsen (Reed); T.J. Visser (Theo); W.E. Visser (Wil Edward)

    2014-01-01

    markdownabstractContext: Thyroid hormones (TH) are important for normal brain development and abnormal TH regulation in the brain results in neurocognitive impairments. The type 2 deiodinase (D2) is important for local TH control in the brain by generating the active hormone T3 from its precursor

  6. Association of High Vitamin D Status with Low Circulating Thyroid-Stimulating Hormone Independent of Thyroid Hormone Levels in Middle-Aged and Elderly Males

    Directory of Open Access Journals (Sweden)

    Qingqing Zhang

    2014-01-01

    Full Text Available Background. A recent study has reported that high circulating 25-hydroxyvitamin D [25(OHD] is associated with low circulating thyroid-stimulating hormone (TSH levels, but only in younger individuals. The goal of the present study was to explore the relationship between vitamin D status and circulating TSH levels with thyroid autoimmunity and thyroid hormone levels taken into consideration in a population-based health survey of middle-aged and elderly individuals. Methods. A total of 1,424 Chinese adults, aged 41–78 years, were enrolled in this cross-sectional study. Serum levels of 25(OHD, TSH, thyroid hormones, and thyroid autoantibodies were measured. Results. The prevalence of vitamin D insufficiency was 94.29% in males and 97.22% in females, and the prevalence of vitamin D deficiency was 55.61% in males and 69.64% in females. Vitamin D status was not associated with positive thyroid autoantibodies after controlling for age, gender, body mass index, and smoking status. Higher 25(OHD levels were associated with lower TSH levels after controlling for age, FT4 and FT3 levels, thyroid volume, the presence of thyroid nodule(s, and smoking status in males. Conclusion. High vitamin D status in middle-aged and elderly males was associated with low circulating TSH levels independent of thyroid hormone levels.

  7. Transcriptional activation by the thyroid hormone receptor through ligand-dependent receptor recruitment and chromatin remodelling

    DEFF Research Database (Denmark)

    Grøntved, Lars; Waterfall, Joshua J; Kim, Dong Wook

    2015-01-01

    A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co...

  8. THYROID HORMONE RECEPTOR BETA GENE MUTATION (P453A) IN A TURKISH FAMILY PRODUCING RESISTANCE TO THYROID HORMONE

    Science.gov (United States)

    Bayraktaroglu, Taner; Noel, Janet; Mukaddes, Nahit Motavalli; Refetoff, Samuel

    2018-01-01

    Two members of a Turkish family, a mother and son, had thyroid function tests suggestive of resistance to thyroid hormone (RTH). The clinical presentation was, however, different. The mother (proposita) had palpitation, weakness, tiredness, nervousness, dry mouth and was misdiagnosed as having multinodular toxic goiter which was treated with antithyroid drugs and partial thyroidectomy. Her younger son had attention deficit hyperactivity disorder and primary encopresis, but normal intellectual quotient. Both had elevated serum iodothyronine levels with nonsuppressed thyrotropin. A mutation in one allele of the thyroid hormone receptor beta gene (P453A) was identified, providing a genetic confirmation for the diagnosis of RTH. PMID:18561095

  9. Molecular Basis for Certain Neuroprotective Effects of Thyroid Hormone

    Directory of Open Access Journals (Sweden)

    Paul eDavis

    2011-10-01

    Full Text Available The pathophysiology of brain damage that is common to ischemia-reperfusion inury and brain trauma includes disordered neuronal and glial cell energetics, intracellular acidosis, calcium toxicity, extracellular excitotoxic glutamate accumulation and dysfunction of the cytoskeleton and endoplasmic reticulum. Thyroid hormone isoforms, 3, 5, 3'-triiodo-L-thyronine (T3 and L-thyroxine (T4, have nongenomic and genomic actions that are relevant to repair of certain features of the pathophysiology of brain damage. Thyroid hormone can nongenomically repair intracullar H+ accumulation by stimulation of the Na+/H+ exchanger and can support desirably low [Ca2+]i.c. by activation of plasma membrane Ca2+-ATPase. Thyroid hormone nongenomically stimulates astrocyte glutamate uptake, an action that protects both glial cells and neurons. The hormone supports the integrity of the cytoskeleton by its effect on actin. Several proteins linked to thyroid hormone action are also neuroprotective. For example, the hormone stimulates expression of the seladin-1 gene whose gene product is anti-apoptotic and is potentially protection in the setting of neurodegeneration. Transthyretin (TTR is a serum transport protein for T4 that is important to blood-brain barrier transfer of the hormone and TTR has also been found to be neuroprotective in the setting of ischemia. Finally, the interesting thyronamine derivatives of T4 have been shown to protect against ischemic brain damage through their ability to induce hypothermia in the intact organism. Thus, thyroid hromone or hormone derivatives have experimental promise as neuroprotective agents.

  10. Lipid Profile and Thyroid Hormones in Types 1 and 2 Diabetics ...

    African Journals Online (AJOL)

    Literature describing relationship between thyroid hormones and lipid levels in Types 1 and 2 diabetics is scanty. Medications used in treating each of the two classes of diabetes differ and the effect of the various hypoglycemic agents on thyroid hormones varies, while thyroid hormone levels relate inversely with cholesterol ...

  11. Thyroid hormone deiodinase type 2 mRNA levels in sea lamprey (Petromyzon marinus) are regulated during metamorphosis and in response to a thyroid challenge.

    Science.gov (United States)

    Stilborn, S Salina M; Manzon, Lori A; Schauenberg, Jennifer D; Manzon, Richard G

    2013-03-01

    Thyroid hormones (THs) are crucial for normal vertebrate development and are the one obligate morphogen that drives amphibian metamorphosis. However, contrary to other metamorphosing vertebrates, lampreys exhibit a sharp drop in serum TH early in metamorphosis, and anti-thyroid agents such as potassium perchlorate (KClO(4)) induce metamorphosis. The type 2 deiodinase (D2) enzyme is a key regulator of TH availability during amphibian metamorphosis. We set out to determine how D2 may be involved in the regulation of lamprey metamorphosis and thyroid homeostasis. We cloned a 1.8Kb Petromyzon marinus D2 cDNA that includes the entire protein coding region and a selenocysteine (Sec) codon. Northern blotting indicated that the lamprey D2 mRNA is the longest reported to date (>9Kb). Using real-time PCR, we showed that intestinal and hepatic D2 mRNA levels were elevated prior to and during the early stages of metamorphosis and then declined dramatically to low levels that were sustained for the remainder of metamorphosis. These data are consistent with previously reported changes in serum TH levels and deiodinase activity. Treatment of larvae with either TH or KClO(4) significantly affected D2 mRNA levels in the intestine and liver. These D2 mRNA levels during metamorphosis and in response to thyroid challenges suggest that D2 may function in the regulation of TH levels during lamprey metamorphosis and the maintenance of TH homeostasis. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Thyroid hormone analogs for the treatment of dyslipidemia: past, present, and future.

    Science.gov (United States)

    Delitala, Alessandro P; Delitala, Giuseppe; Sioni, Paolo; Fanciulli, Giuseppe

    2017-11-01

    Treatment of dyslipidemia is a major burden for public health. Thyroid hormone regulates lipid metabolism by binding the thyroid hormone receptor (TR), but the use of thyroid hormone to treat dyslipidemia is not indicated due to its deleterious effects on heart, bone, and muscle. Thyroid hormone analogs have been conceived to selectively activate TR in the liver, thus reducing potential side-effects. The authors searched the PubMed database to review TR and the action of thyromimetics in vitro and in animal models. Then, all double-blind, placebo controlled trials that analyzed the use of thyroid hormone analog for the treatment of dyslipidemia in humans were included. Finally, the ongoing research on the use of TR agonists was searched, searching the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform (ICTRP). Thyromimetics were tested in humans for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional lipid-lowering drugs. In most trials, thyromimetics lowered total cholesterol, low-density lipoprotein cholesterol, and triglycerides, but their use has been associated with adverse side-effects, both in pre-clinical studies and in humans. The use of thyromimetics for the treatment of dyslipidemia is not presently recommended. Future possible clinical applications might include their use to promote weight reduction. Thyromimetics might also represent an interesting alternative, both for the treatment of non-alcoholic steatohepatitis, and type 2 diabetes due to their positive effects on insulin sensitivity. Finally, additional experimental and clinical studies are needed for a better comprehension of the effect(s) of a long-term therapy.

  13. Central regulation of the hypothalamo-pituitary-thyroid (HPT) axis: focus on clinical aspects

    NARCIS (Netherlands)

    Fliers, E.; Boelen, A.; van Trotsenburg, A. S. P.

    2014-01-01

    The hypothalamus is the most prominent brain region involved in setpoint regulation of the thyroid axis. It generates the diurnal thyroid-stimulating hormone (TSH) rhythm, and it plays a central role in the adaptation of the thyroid axis to environmental factors such as caloric deprivation or

  14. Thyroid hormone modulates insulin-like growth factor-I(IGF-I) and IGF-binding protein-3, without mediation by growth hormone, in patients with autoimmune thyroid diseases.

    Science.gov (United States)

    Inukai, T; Takanashi, K; Takebayashi, K; Fujiwara, Y; Tayama, K; Takemura, Y

    1999-10-01

    The expression and synthesis of insulin-like growth factor-1 (IGF-I) and IGF-binding protein-3 (IGFBP-3) are regulated by various hormones and nutritional conditions. We evaluated the effects of thyroid hormones on serum levels of IGF-I and IGFBP-3 levels in patients with autoimmune thyroid diseases including 54 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis, and in 32 healthy age-matched control subjects. Patients were subdivided into hyperthyroid, euthyroid and hypothyroid groups that were untreated, or were treated with methylmercaptoimidazole (MMI) or L-thyroxine (L-T4). Serum levels of growth hormone (GH), IGF-I and IGFBP-3 were determined by radioimmunoassay. Serum GH levels did not differ significantly between the hyperthyroid and the age-matched euthyroid patients with Graves' disease. The serum levels of IGF-I and IGFBP-3 showed a significant positive correlation in the patients (R=0.616, Phyperthyroid patients with Graves' disease or in those with Hashimoto's thyroiditis induced by excess L-T4 administration than in control subjects. Patients with hypothyroid Graves' disease induced by the excess administration of MMI showed significantly lower IGFBP-3 levels as compared to those in healthy controls (Phormone modulates the synthesis and/or the secretion of IGF-I and IGFBP-3, and this function is not mediated by GH.

  15. Improved radioimmunoassay for thyroid hormone and reagent

    International Nuclear Information System (INIS)

    1980-01-01

    Improvements in the radioimmunoassay of the thyroid hormones, thyroxine or triiodothyronine, are described. Hydrolyzed cross-linked polyacrylamide particles covalently bonded against the thyroid hormone are employed as solid phase substrates for the thyroid hormone antibodies. The polyacrylamide particles are dyed yellow or blue to facilitate the various manipulative steps during the radioimmunoassay. The particles are characterized by their ability to form stable hydrophilic suspensions. As a result the reaction mixture, during which thyroid hormone is separated from serum proteins and competitive binding in the presence of radioactive tracer with the antibody occurs, requires no agitation to maintain the desired homogeneous condition. This is in contrast to the settling problems experienced with cellulose, dextran and glass particles. In addition, the non-specific binding property of the polyacrylamide particles is so low that the initially separated solid phase particles following incubation can be directly measured for radioactivity levels without any initial washings thus increasing the speed and convenience of the assay procedure. Details of the preparation of the dyed, hydrolyzed polyacrylamide particles, the coupling of antiserum to these particles and the radioimmunoassay procedure are given. Data obtained from the radioimmunoassays of hypothyroid, euthyroid and hyperthyroid sera demonstrated the satisfactory performance of the assay. (U.K.)

  16. Interactions of polyhalogenated aromatic hydrocarbons with thyroid hormone metabolism

    NARCIS (Netherlands)

    Schuur, A.G.

    1998-01-01

    This thesis deals with the possible interactions of polyhalogenated aromatic hydrocarbons and/or their metabolites with thyroid hormone metabolism. This chapter summarizes firstly the effects of thyroid hormone on the induction of biotransformation enzymes by PHAHs. Secondly, the results on

  17. Thyroid Homoeostasis and Reproductive Hormonal Disorders in Women

    Directory of Open Access Journals (Sweden)

    А.А. Yunusov

    2014-11-01

    Full Text Available Objective of the study — to investigate the influence of hypo- and hyperthyroidism on the state of reproductive function for women and to estimate efficiency of treatment. Material and Methods. 156 women of reproductive age are examined concerning inflammatory gynaecological and endocrine disorders. Complex of laboratory and clinical investigations included: anamnesis, examination; unified clinical and biochemical methods of research; studying research hormones in blood plasma (thyroid stimulating hormone, prolactine, Т3, Т4, fТ4, antibodies to thyroglobulin, thyroid peroxidase; luteinizing hormone, follicle-stimulating hormone (FSH, estradiol, progesteron, testosteron; ultrasonic examination of thyroid gland, mammary gland, pelvic organs; radiography of sella turcica; fine needle biopsy of the thyroid. Results. The comparative analysis of different pathologies of reproductive function in both clinical groups showed, that infertility, both primary and secondary, prevailed in the group with hypothyroidism — 66 vs 33.3 % in the group of women with hyperthyroidism. In the first clinical group, signs of menstrual disorders (68.2 %, galactorrhea (63.6 %, breast pathology (55 % also prevailed, while in the second group these indexes were 38.8, 22.2 and 33.3 %, respectively. In the structure of menstrual disorders, oligomenorrhea prevailed in both clinical groups — 47 and 57 %. Most women (76.9 % had I degree of galactorrhea and bilateral galactorrhea (80.7 %. Cervical pathology was detected 45 % of women, with predominance of pseudoerosion (55.5 %, and in 12.5% — hysteromyoma. Chronic salpingo-oophoritis was diagnosed in 47.5 % of patients, cystic ovaries — in 10 % of women of clinical group. Conclusions. Thyroid pathology in women of reproductive age is characterized by autoimmune thyroiditis (24.3 %, diffuse toxic goiter (10.8 % and nodular goiter (16.2 %. Women with thyroid hormone deficit have a decline of gonadotropic pituitary

  18. Differential regulation of thyrotropin subunit apoprotein and carbohydrate biosynthesis by thyroid hormone

    International Nuclear Information System (INIS)

    Taylor, T.; Weintraub, B.D.

    1985-01-01

    The regulation of TSH apoprotein and carbohydrate biosynthesis by thyroid hormone was studied by incubating pituitaries from normal and hypothyroid (3 weeks post-thyroidectomy) rats in medium containing [ 14 C]alanine and [ 3 H] glucosamine. After 6 h, samples were sequentially treated with anti-TSH beta to precipitate TSH and free TSH beta, anti-LH beta to clear the sample of LH and free LH beta, then anti-LH alpha to precipitate free alpha-subunit. Total proteins were acid precipitated. All precipitates were subjected to electrophoresis on sodium dodecyl sulfate-polyacrylamide gels, which were then sliced and assayed by scintillation spectrometry. In hypothyroid pituitaries plus medium, [ 14 C]alanine incorporation in combined and free beta-subunits was 26 times normal and considerably greater than the 3.4-fold increase seen in total protein; combined and free alpha-subunits showed no specific increase in apoprotein synthesis. [ 3 H]Glucosamine incorporation in combined alpha- and beta-subunits in hypothyroid samples was 13 and 21 times normal, respectively, and was greater than the 1.9-fold increase in total protein; free alpha-subunit showed no specific increase in carbohydrate synthesis. The glucosamine to alanine ratio, reflecting relative glycosylation of newly synthesized molecules, was increased in hypothyroidism for combined alpha-subunits, but not for combined beta-subunits, free alpha-subunits, or total proteins. In summary, short term hypothyroidism selectively stimulated TSH beta apoprotein synthesis and carbohydrate synthesis of combined alpha- and beta-subunits. Hypothyroidism also increased the relative glycosylation of combined alpha-subunit. Thus, thyroid hormone deficiency appears to alter the rate-limiting step in TSH assembly (i.e. beta-subunit synthesis) as well as the carbohydrate structure of TSH, which may play important roles in its biological function

  19. Interactions between the thyroid hormones and the hormones of the growth hormone axis.

    Science.gov (United States)

    Laron, Zvi

    2003-12-01

    The normal secretion and action of the thyroid hormones and the hormones of the GH/IGF-I (growth hormone/ insulin-like growth factor I) axis are interdependent. Their interactions often differ in man from animal studies in rodents and sheep. Thus neonates with congenital hypothyroidism are of normal length in humans but IUGR (intrauterine growth retardation) in sheep. Postnatally normal GH/IGF-I secretion and action depends on an euthyroid state. Present knowledge on the interactions between the two axes is reviewed in states of hypo- and hyperthyroidism, states of GH/IGF-I deprivation and hypersecretion, as well as the relationship between IGF-I and thyroid cancer. Emphasis is given to data in children and aspects of linear growth and skeletal maturation.

  20. TSH (Thyroid-stimulating hormone) test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Thyroid-Stimulating Hormone, Serum; p. 484. ...

  1. Effects of sex steroid hormones, thyroid hormone levels, and insulin regulation on thyrotoxic periodic paralysis in Chinese men

    OpenAIRE

    Li, Wang; Changsheng, Chen; Jiangfang, Fu; Bin, Gao; Nanyan, Zhang; Xiaomiao, Li; Deqiang, Li; Ying, Xing; Wensong, Zai; Qiuhe, Ji

    2010-01-01

    Our study is to determine the expression of thyroid hormone, sex hormone, insulin, and C-peptide in Chinese male patients with thyrotoxic periodic paralysis (TPP). This study covered 102 patients with hyperthyroidism from Xijing Hospital. According to whether occurrence of TPP or not, patients were divided into two groups (those that were hyperthyroid with and without TPP) that were, matched with age, blood pressure, urea, and creatinine. We found the body mass index (BMI) in patients with TP...

  2. Thyroid hormone regulation of epidermal growth factor receptor levels in mouse mammary glands

    International Nuclear Information System (INIS)

    Vonderhaar, B.K.; Tang, E.; Lyster, R.R.; Nascimento, M.C.

    1986-01-01

    The specific binding of iodinated epidermal growth factor ([ 125 I]iodo-EGF) to membranes prepared from the mammary glands and spontaneous breast tumors of euthyroid and hypothyroid mice was measured in order to determine whether thyroid hormones regulate the EGF receptor levels in vivo. Membranes from hypothyroid mammary glands of mice at various developmental ages bound 50-65% less EGF than those of age-matched euthyroid controls. Treatment of hypothyroid mice with L-T4 before killing restored binding to the euthyroid control level. Spontaneous breast tumors arising in hypothyroid mice also bound 30-40% less EGF than tumors from euthyroid animals even after in vitro desaturation of the membranes of endogenous growth factors with 3 M MgCl2 treatment. The decrease in binding in hypothyroid membranes was due to a decrease in the number of binding sites, not to a change in affinity of the growth factor for its receptor, as determined by Scatchard analysis of the binding data. Both euthyroid and hypothyroid membranes bound EGF primarily to a single class of high affinity sites [dissociation constant (Kd) = 0.7-1.8 nM]. Euthyroid membranes bound 28.4 +/- (SE) 0.6 fmol/mg protein, whereas hypothyroid membranes bound 15.5 +/- 1.0 fmol/mg protein. These data indicate that EGF receptor levels in normal mammary glands and spontaneous breast tumors in mice are subject to regulation by thyroid status

  3. Determination of the concentration of thyroid hormone in dialysate and assessment of the loss of thyroid hormone during hemodialysis

    International Nuclear Information System (INIS)

    Beyer, H.K.; Schuster, P.; Pressler, H.; Bochum Univ.

    1980-01-01

    In order to determine the hormone concentration in a dialysate, the commercially available radioimmunossay test of Dow-Lepetit for determination of free thyroid hormones in serum had to be modified. The results raised the suspicion that additional protein-bound hormone had passed the membrane. This could be demonstrated by the addition of Thiomersal. In 64 patients examined 1 and 5 hrs after the beginning of hemodialysis the mean total hormone concentration in the dialysate was 12.05 pg/ml for thyroxine and 5.47 pg/ml for triiodothyronine. The resulting loss of total hormone in hemodialysis patients, calculated for 1 week, amounted to 2.25 μg triiodothyronine and 4.87 μg thyroxine. The comparison with the physiologic renal elimination of thyroid hormone shows that the hormone elimination in hemodialysis patients is negligibly small. The quantitative determination of the protein concentration in the dialysate however, that the loss of protein is without clinical relevance. (orig.) [de

  4. Thyroid hormone resistance misdiagnosed as Graves' disease

    Directory of Open Access Journals (Sweden)

    Manish Gutch

    2017-01-01

    Full Text Available Resistance to thyroid hormone (RTH syndrome is a very rare disorder characterized by mutations of the thyroid hormone receptor beta and is usually inherited as an autosomal dominant trait. Patients with RTH are usually euthyroid but rarely may present with signs and symptoms consistent with hyperthyroidism. Here, we describe the case of a young girl with goiter who was previously misdiagnosed to have hyperthyroidism and was subsequently diagnosed to be suffering from RTH.

  5. Cholinergic and VIPergic effects on thyroid hormone secretion in the mouse

    International Nuclear Information System (INIS)

    Ahren, B.

    1985-01-01

    The thyroid gland is known to harbor cholinergic and VIPergic nerves. In the present study, the influences of cholinergic stimulation by carbachol, cholinergic blockade by methylatropine and stimulation with various VIP sequences on basal, TSH-induced and VIP-induced thyroid hormone secretion were investigated in vivo in mice. The mice were pretreated with 125 I and thyroxine; the subsequent release of 125 I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was inhibited by both carbachol and methylatropine. Furthermore, TSH-induced radioiodine secretion was inhibited already by a low dose of carbachol. Moreover, a high dose of carbachol could inhibit VIP-induced radioiodine secretion. Methylatropine did not influence TSH- or VIP-stimulated radioiodine secretion, but counteracted the inhibitory action of carbachol on TSH- and VIP-induced radioiodine release. In addition, contrary to VIP, six various synthesized VIP fragments had no effect on basal or stimulated radioiodine release. It is concluded that basal thyroid hormone secretion is inhibited by both cholinergic activation and blockade. Furthermore, TSH-induced thyroid hormone secretion is more sensitive to inhibition with cholinergic stimulation than is VIP-induced thyroid hormone secretion. In addition, the VIP stimulation of thyroid hormone secretion seems to require the full VIP sequence

  6. Thyroid hormones and lipid phosphorus in mice

    Energy Technology Data Exchange (ETDEWEB)

    Thakare, U R; Ganatra, R D; Shah, D H [Bhabha Atomic Research Centre, Bombay (India). Radiation Medicine Centre

    1978-04-01

    In vivo studies in mice injected intravenously with /sup 125/I-triiodothyronine (T-3) showed a linear relationship between the uptake of the labelled hormone by the tissue and the lipid phosphorous content of the same tissue. However, studies with /sup 125/I-thyroxine failed to show a similar relationship between the lipid phosphorous content of the organ and the uptake of radioactive hormone by the same organ. In vitro studies using equilibrium dialysis technique with isolated lipid extracts of various organs and radioactive thyroid hormones (T-3 and T-4) did not show any relation between the lipid P and the uptake of labelled hormone. On the basis of the observed discrepancy between in vivo and in vitro studies, it is postulated that an organized lipoprotein structure at the cell membrane may be responsible for the entry of the thyroid hormones.

  7. Action of Specific Thyroid Hormone Receptor alpha(1) and beta(1) Antagonists in the Central and Peripheral Regulation of Thyroid Hormone Metabolism in the Rat

    NARCIS (Netherlands)

    van Beeren, Hermina C.; Kwakkel, Joan; Ackermans, Mariëtte T.; Wiersinga, Wilmar M.; Fliers, Eric; Boelen, Anita

    2012-01-01

    Background: The iodine-containing drug amiodarone (Amio) and its noniodine containing analogue dronedarone (Dron) are potent antiarrhythmic drugs. Previous in vivo and in vitro studies have shown that the major metabolite of Amio, desethylamiodarone, acts as a thyroid hormone receptor (TR) alpha(1)

  8. Temperature induced variation in gene expression of thyroid hormone receptors and deiodinases of European eel (Anguilla anguilla) larvae

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Servili, A.; Mazurais, D.

    2018-01-01

    Thyroid hormones (THs) are key regulators of growth, development, and metabolism in vertebrates and influence early life development of fish. TH is produced in the thyroid gland (or thyroid follicles) mainly as T4 (thyroxine), which is metabolized to T3 (3,5,3'-triiodothyronine) and T2 (3...

  9. [Thyroid hormones and cardiovascular system].

    Science.gov (United States)

    Límanová, Zdeňka; Jiskra, Jan

    Cardiovascular system is essentially affected by thyroid hormones by way of their genomic and non-genomic effects. Untreated overt thyroid dysfunction is associated with higher cardiovascular risk. Although it has been studied more than 3 decades, in subclinical thyroid dysfunction the negative effect on cardiovascular system is much more controversial. Large meta-analyses within last 10 years have shown that subclinical hyperthyroidism is associated with higher cardiovascular risk than subclinical hypothyroidism. Conversely, in patients of age > 85 years subclinical hypothyroidism was linked with lower mortality. Therefore, subclinical hyperthyroidism should be rather treated in the elderly while subclinical hypothyroidism in the younger patients and the older may be just followed. An important problem on the border of endocrinology and cardiology is amiodarone thyroid dysfunction. Effective and safe treatment is preconditioned by distinguishing of type 1 and type 2 amiodarone induced hyperthyroidism. The type 1 should be treated with methimazol, therapeutic response is prolonged, according to recent knowledge immediate discontinuation of amiodarone is not routinely recommended and patient should be usually prepared to total thyroidectomy, or rather rarely 131I radioiodine ablation may be used if there is appropriate accumulation. In the type 2 there is a promt therapeutic response on glucocorticoids (within 1-2 weeks) with permanent remission or development of hypothyroidism. If it is not used for life-threatening arrhytmias, amiodarone may be discontinuated earlier (after several weeks). Amiodarone induced hypothyroidism is treated with levothyroxine without amiodarone interruption.Key words: amiodarone induced thyroid dysfunction - atrial fibrillation - cardiovascular risk - heart failure - hyperthyroidism - hypothyroidism - thyroid stimulating hormone.

  10. Free thyroid hormones in patients with severe non-thyroidal illness

    International Nuclear Information System (INIS)

    Boettger, I.; Schneck, H.W.; Technische Univ. Muenchen

    1985-01-01

    Free thyroid hormone radioligand assays and indirect methods for FT 4 and FT 3 were applied to measurement in sera of patients with severe NTI (hemodialysis, intensive-care, polytrauma). FT 4 by different techniques was low-normal to decreased by a kinetic two-tube and a T 4 -analogue tracer single-tube assay whereas another two-tube technique measured normal to low-normal but in some instances increased FT 4 levels. Indirect parameters behaved in a similar fashion. FT 3 was decreased in most of the cases as were the indirect parameters, mostly due to affected T 4 -T 3 conversion. Direct and indirect parameters for free thyroid hormones changed in parallel also during follow-up of NTI. There was no clear protein or albumen effect upon the two-tube FT 4 and the two-tube FT 3 assay(s). Supersensitively determined basal TSH was found to be decreased in some cases with severe NTI (polytrauma). The findings taken together are consistent with (pseudo) sedondary hypothyroidism in severe NTI. The data show the free thyroid hormone assays tested to be rather reliable with little or no disturbance by severe NTI or specifically hypoalbumenemia. (orig.)

  11. Skeletal muscle expression of p43, a truncated thyroid hormone receptor α, affects lipid composition and metabolism.

    Science.gov (United States)

    Casas, François; Fouret, Gilles; Lecomte, Jérome; Cortade, Fabienne; Pessemesse, Laurence; Blanchet, Emilie; Wrutniak-Cabello, Chantal; Coudray, Charles; Feillet-Coudray, Christine

    2018-02-01

    Thyroid hormone is a major regulator of metabolism and mitochondrial function. Thyroid hormone also affects reactions in almost all pathways of lipids metabolism and as such is considered as the main hormonal regulator of lipid biogenesis. The aim of this study was to explore the possible involvement of p43, a 43 Kda truncated form of the nuclear thyroid hormone receptor TRα1 which stimulates mitochondrial activity. Therefore, using mouse models overexpressing p43 in skeletal muscle (p43-Tg) or lacking p43 (p43-/-), we have investigated the lipid composition in quadriceps muscle and in mitochondria. Here, we reported in the quadriceps muscle of p43-/- mice, a fall in triglycerides, an inhibition of monounsaturated fatty acids (MUFA) synthesis, an increase in elongase index and an decrease in desaturase index. However, in mitochondria from p43-/- mice, fatty acid profile was barely modified. In the quadriceps muscle of p43-Tg mice, MUFA content was decreased whereas the unsaturation index was increased. In addition, in quadriceps mitochondria of p43-Tg mice, we found an increase of linoleic acid level and unsaturation index. Last, we showed that cardiolipin content, a key phospholipid for mitochondrial function, remained unchanged both in quadriceps muscle and in its mitochondria whatever the mice genotype. In conclusion, this study shows that muscle lipid content and fatty acid profile are strongly affected in skeletal muscle by p43 levels. We also demonstrate that regulation of cardiolipin biosynthesis by the thyroid hormone does not imply p43.

  12. Central and peripheral effects of thyroid hormone signalling in the control of energy metabolism

    NARCIS (Netherlands)

    Alkemade, A.

    2010-01-01

    Increasing evidence points towards a role for thyroid hormone signalling in the central nervous system with respect to the development of symptoms of thyroid disease, in addition to the well-known peripheral effects of thyroid hormone. Thyroid hormone affects target tissues directly via thyroid

  13. Thyroid-stimulating hormone, anti-thyroid antibodies, and pregnancy outcomes.

    Science.gov (United States)

    Plowden, Torie C; Schisterman, Enrique F; Sjaarda, Lindsey A; Perkins, Neil J; Silver, Robert; Radin, Rose; Kim, Keewan; Galai, Noya; DeCherney, Alan H; Mumford, Sunni L

    2017-12-01

    Overt thyroid dysfunction has been associated with adverse obstetric outcomes. However, less is known regarding subclinical hypothyroidism or thyroid autoimmunity and their relationship to pregnancy complications. The purpose of this study was to examine the association between prepregnancy anti-thyroid antibodies and subclinical hypothyroidism and preterm delivery, gestational diabetes mellitus, and preeclampsia. We conducted a secondary analysis of a prospective cohort of 18- to 40-year-old women with 1-2 previous pregnancy losses (n=1193) who participated in a multicenter randomized, placebo-controlled trial of low-dose aspirin. Prepregnancy levels of thyroid-stimulating hormone, free thyroxine, thyroglobulin antibody, and thyroid peroxidase antibody were measured. Relative risks and 95% confidence intervals were estimated with the use of generalized linear models with adjustment for age and body mass index. Among women with an ongoing pregnancy of >20 weeks estimated gestational age, there was no association between prepregnancy thyroid-stimulating hormone level (>2.5 vs ≤2.5 mIU/L) and preterm delivery (adjusted relative risk, 0.77; 95% confidence interval, 0.40-1.47), gestational diabetes mellitus (adjusted relative risk, 1.28; 95% confidence interval, 0.54-3.04), or preeclampsia (adjusted relative risk, 1.20; 95% confidence interval, 0.71-2.04). Similarly, among women with thyroid antibodies, there was no increase in the likelihood of preterm delivery (relative risk, 1.26; 95% confidence interval, 0.65-2.45), gestational diabetes mellitus (relative risk, 1.33; 95% confidence interval, 0.51-3.49), or preeclampsia (relative risk, 1.02; 95% confidence interval, 0.54-1.92), compared with women without these antibodies. Among women with 1-2 previous pregnancy losses, subclinical hypothyroidism and thyroid autoimmunity were not associated with an increased risk of preterm delivery, gestational diabetes mellitus, or preeclampsia. These data support current

  14. A Case of Resistance to Thyroid Hormone with Chronic Thyroiditis: Discovery of a Novel Mutation (I54V

    Directory of Open Access Journals (Sweden)

    I. Kammoun

    2011-01-01

    Full Text Available Resistance to thyroid hormone (RTH is a rare disorder characterized by variable tissue hyporesponsiveness to thyroid hormone, usually caused by mutations in the thyroid hormone receptor beta (TRβ. It has been reported that the serum of patients with RTH is free of auto-antibodies against thyroglobulin (Tg and thyroid peroxidase (TPO, except in rare cases where coincidental autoimmune thyroiditis is also present. We describe a 13-year-old girl with chronic thyroiditis and RTH. This patient had increased plasma free T3, free T4 at the upper limits with unsuppressed TSH. She had peripheral manifestations of thyroid hormone excess, hypertension and growth acceleration. Anti-TPO antibodies were positive. Sequence analysis of the TRβ gene was performed and revealed a novel mutation I54V in exon 4. The same mutation was also found in the mother and two asymptomatic sisters. The clinical presentation of our patient is not habitual in RTH because growth retardation is frequently reported in this syndrome. The association between RTH and thyroiditis complicate the management of the hypothyroidism.

  15. Effects of phenobarbital on thyroid hormone contabolism in rat hepatocytes

    Science.gov (United States)

    Hepatic enzyme inducers such as phenobarbital (PB) decrease circulating thyroid hormone (TH) concentrations in rodents. PB induction of hepatic xenobiotic metabolizing enzymes increases thyroid hormones catabolism and biliary elimination. This study examines the catabolism and cl...

  16. Physiological Regulation of Gut Peptide Hormone (PYY) Levels by Age, Sex, Hormonal and Nutritional Status in Rats

    International Nuclear Information System (INIS)

    Hebashy, M.I.A.; Mazen, G.M.A.

    2007-01-01

    Peptide YY hormone (PYY) was recently appreciated as an important gut hormonal regulator of appetite. PYY is produced by the gut and released into the circulation after food intake and is found to decrease appetite. The main form of PYY, both stored and circulated, is PYY(3-36), the N-terminal truncated form of the full length peptide so, peripheral injections of PYY(3-36) in rats inhibit food intake in experimental animals as well as in lean and obese human subjects. Also, this hormone has been suggested to be an attractive therapeutic option for obesity. PYY levels are influenced by age and the highest hormone level is achieved in early postnatal life (day 30) and is decreased thereafter. PYY levels were also dependent on thyroid hormone status and being decreased in hyperthyroid rats. The PYY levels observed in acute and chronic food restricted rats indicated that, in situations of decreased energy intake, the lower PYY levels could serve to regulate central pathways and facilitate food intake. Contrary, in pregnant rats, PYY levels were enhanced at late gestation. The aim of this study was to assess the influence of age, sex, thyroid status, pregnancy and food restriction on PYY levels in rats. The underling mechanisms through which PYY levels alternated as a result of sex, age, pregnancy, thyroidal and nutritional status were discussed in the light of recent research outcomes

  17. Profile of thyroid hormones in breast cancer patients

    Directory of Open Access Journals (Sweden)

    P.P. Saraiva

    2005-05-01

    Full Text Available Estrogen involvement in breast cancer has been established; however, the association between breast cancer and thyroid diseases is controversial. Estrogen-like effects of thyroid hormone on breast cancer cell growth in culture have been reported. The objective of the present study was to determine the profile of thyroid hormones in breast cancer patients. Serum aliquots from 26 patients with breast cancer ranging in age from 30 to 85 years and age-matched normal controls (N = 22 were analyzed for free triiodothyronine (T3F, free thyroxine (T4F, thyroid-stimulating hormone (TSH, antiperoxidase antibody (TPO, and estradiol (E2. Estrogen receptor ß (ERß was determined in tumor tissues by immunohistochemistry. Thyroid disease incidence was higher in patients than in controls (58 vs 18%, P < 0.05. Subclinical hyperthyroidism was the most frequent disorder in patients (31%; hypothyroidism (8% and positive anti-TPO antibodies (19% were also found. Subclinical hypothyroidism was the only dysfunction (18% found in controls. Hyperthyroidism was associated with postmenopausal patients, as shown by significantly higher mean T3 and T4 values and lower TSH levels in this group of breast cancer patients than in controls. The majority of positive ERß tumors were clustered in the postmenopausal patients and all cases presenting subclinical hyperthyroidism in this subgroup concomitantly exhibited Erß-positive tumors. Subclinical hyperthyroidism was present in only one of 6 premenopausal patients. We show here that postmenopausal breast cancer patients have a significantly increased thyroid hormone/E2 ratio (P < 0.05, suggesting a possible tumor growth-promoting effect caused by this misbalance.

  18. The Influence of Thyroid Hormones on Leptin and Resistin Levels in Hyperthyroid Female Patients

    Directory of Open Access Journals (Sweden)

    Al-Hindawi Sahar H

    2018-01-01

    Full Text Available Background: Hyperthyroidism or thyrotoxicosis occurs due to excess release of thyroid hormone. These hormones regulate the body’s energy balance and have effects on adipokine level. There are several reports suggesting interrelation between adipokines (resistin and leptin with thyroid dysfunction. Objectives: This study was established to investigate the effect of thyroid hormones in hyperthyroidism state on the level of some adipokines, leptin and resistin; in comparison with control. Patients and Methods: The present study included 50 Iraqi female patients with hyperthyroidism with age ranged between 30-58 years and 30 healthy controls with age ranged between 30-53 years. Serum samples were collected from study groups. The levels of thyroid hormones (TSH, T4 and T3 were determined by using automated Chemiluminescence Immunoassay (CLIA analysis system. Detection of leptin hormone and resistin hormone levels in the serum were determined by an enzyme linked immunosorbent assay (ELISA kits. Results: The results revealed that serum leptin levels were significantly low (P<0.004 in hyperthyroid patient groups as compared to control, and there were significant negative correlations between T4 and leptin (P<0.0001; also, T3 and leptin (P<0.05. Resistin hormone level increased non-significantly (P˃0.05 than control level; and there was significant negative correlation between TSH and resistin (P<0.035. Conclusion: The study shows that there is complex interrelation between adipocytokines (leptin and resistin with thyroid gland and pituitary gland. Leptin levels were decreased in hyperthyroid patients than control and associated negatively with T4 and T3 levels, while resistin levels were increased non-significantly than control and associated negatively with TSH level. They affect each other in their physiological function in the human body.

  19. The Role of Thyroid Hormone Signaling in the Prevention of Digestive System Cancers

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    Rosalia C. M. Simmen

    2013-08-01

    Full Text Available Thyroid hormones play a critical role in the growth and development of the alimentary tract in vertebrates. Their effects are mediated by nuclear receptors as well as the cell surface receptor integrin αVβ3. Systemic thyroid hormone levels are controlled via activation and deactivation by iodothyronine deiodinases in the liver and other tissues. Given that thyroid hormone signaling has been characterized as a major effector of digestive system growth and homeostasis, numerous investigations have examined its role in the occurrence and progression of cancers in various tissues of this organ system. The present review summarizes current findings regarding the effects of thyroid hormone signaling on cancers of the esophagus, stomach, liver, pancreas, and colon. Particular attention is given to the roles of different thyroid hormone receptor isoforms, the novel integrin αVβ3 receptor, and thyroid hormone-related nutrients as possible protective agents and therapeutic targets. Future investigations geared towards a better understanding of thyroid hormone signaling in digestive system cancers may provide preventive or therapeutic strategies to diminish risk, improve outcome and avert recurrence in afflicted individuals.

  20. Thyroid hormone receptor beta2 is strongly up-regulated at all levels of the hypothalamo-pituitary-thyroidal axis during late embryogenesis in chicken.

    Science.gov (United States)

    Grommen, Sylvia V H; Arckens, Lutgarde; Theuwissen, Tim; Darras, Veerle M; De Groef, Bert

    2008-03-01

    In this study, we tried to elucidate the changes in thyroid hormone (TH) receptor beta2 (TRbeta2) expression at the different levels of the hypothalamo-pituitary-thyroidal (HPT) axis during the last week of chicken embryonic development and hatching, a period characterized by an augmented activity of the HPT axis. We quantified TRbeta2 mRNA in retina, pineal gland, and the major control levels of the HPT axis - brain, pituitary, and thyroid gland - at day 18 of incubation, and found the most abundant mRNA content in retina and pituitary. Thyroidal TRbeta2 mRNA content increased dramatically between embryonic day 14 and 1 day post-hatch. In pituitary and hypothalamus, TRbeta2 mRNA expression rose gradually, in parallel with increases in plasma thyroxine concentrations. Using in situ hybridization, we have demonstrated the presence of TRbeta2 mRNA throughout the diencephalon and confirmed the elevation in TRbeta2 mRNA expression in the hypophyseal thyrotropes. In vitro incubation with THs caused a down-regulation of TRbeta2 mRNA levels in embryonic but not in post-hatch pituitaries. The observed expression patterns in pituitary and diencephalon may point to substantial changes in TRbeta2-mediated TH feedback active during the perinatal period. The strong rise in thyroidal TRbeta2 mRNA content could be indicative of an augmented modulation of thyroid development and/or function by THs toward and after hatching. Finally, THs proved to exert an age-dependent effect on pituitary TRbeta2 mRNA expression.

  1. Thyroid Hormones and Antioxidant Systems: Focus on Oxidative Stress in Cardiovascular and Pulmonary Diseases

    Directory of Open Access Journals (Sweden)

    Antonio Mancini

    2013-12-01

    Full Text Available In previous works we demonstrated an inverse correlation between plasma Coenzyme Q10 (CoQ10 and thyroid hormones; in fact, CoQ10 levels in hyperthyroid patients were found among the lowest detected in human diseases. On the contrary, CoQ10 is elevated in hypothyroid subjects, also in subclinical conditions, suggesting the usefulness of this index in assessing metabolic status in thyroid disorders. A Low-T3 syndrome is a condition observed in several chronic diseases: it is considered an adaptation mechanism, where there is a reduction in pro-hormone T4 conversion. Low T3-Syndrome is not usually considered to be corrected with replacement therapy. We review the role of thyroid hormones in regulation of antioxidant systems, also presenting data on total antioxidant capacity and Coenzyme Q10. Published studies suggest that oxidative stress could be involved in the clinical course of different heart diseases; our data could support the rationale of replacement therapy in low-T3 conditions.

  2. Role of Estrogen in Thyroid Function and Growth Regulation

    Directory of Open Access Journals (Sweden)

    Ana Paula Santin

    2011-01-01

    Full Text Available Thyroid diseases are more prevalent in women, particularly between puberty and menopause. It is wellknown that estrogen (E has indirect effects on the thyroid economy. Direct effects of this steroid hormone on thyroid cells have been described more recently; so, the aim of the present paper was to review the evidences of these effects on thyroid function and growth regulation, and its mechanisms. The expression and ratios of the two E receptors, α and β, that mediate the genomic effects of E on normal and abnormal thyroid tissue were also reviewed, as well as nongenomic, distinct molecular pathways. Several evidences support the hypothesis that E has a direct role in thyroid follicular cells; understanding its influence on the growth and function of the thyroid in normal and abnormal conditions can potentially provide new targets for the treatment of thyroid diseases.

  3. Hypothalamic AMPK and fatty acid metabolism mediate thyroid regulation of energy balance.

    Science.gov (United States)

    López, Miguel; Varela, Luis; Vázquez, María J; Rodríguez-Cuenca, Sergio; González, Carmen R; Velagapudi, Vidya R; Morgan, Donald A; Schoenmakers, Erik; Agassandian, Khristofor; Lage, Ricardo; Martínez de Morentin, Pablo Blanco; Tovar, Sulay; Nogueiras, Rubén; Carling, David; Lelliott, Christopher; Gallego, Rosalía; Oresic, Matej; Chatterjee, Krishna; Saha, Asish K; Rahmouni, Kamal; Diéguez, Carlos; Vidal-Puig, Antonio

    2010-09-01

    Thyroid hormones have widespread cellular effects; however it is unclear whether their effects on the central nervous system (CNS) contribute to global energy balance. Here we demonstrate that either whole-body hyperthyroidism or central administration of triiodothyronine (T3) decreases the activity of hypothalamic AMP-activated protein kinase (AMPK), increases sympathetic nervous system (SNS) activity and upregulates thermogenic markers in brown adipose tissue (BAT). Inhibition of the lipogenic pathway in the ventromedial nucleus of the hypothalamus (VMH) prevents CNS-mediated activation of BAT by thyroid hormone and reverses the weight loss associated with hyperthyroidism. Similarly, inhibition of thyroid hormone receptors in the VMH reverses the weight loss associated with hyperthyroidism. This regulatory mechanism depends on AMPK inactivation, as genetic inhibition of this enzyme in the VMH of euthyroid rats induces feeding-independent weight loss and increases expression of thermogenic markers in BAT. These effects are reversed by pharmacological blockade of the SNS. Thus, thyroid hormone-induced modulation of AMPK activity and lipid metabolism in the hypothalamus is a major regulator of whole-body energy homeostasis.

  4. Hypothalamic AMPK and fatty acid metabolism mediate thyroid regulation of energy balance

    Science.gov (United States)

    López, Miguel; Varela, Luis; Vázquez, María J.; Rodríguez-Cuenca, Sergio; González, Carmen R.; Velagapudi, Vidya R.; Morgan, Donald A.; Schoenmakers, Erik; Agassandian, Khristofor; Lage, Ricardo; de Morentin, Pablo Blanco Martínez; Tovar, Sulay; Nogueiras, Rubén; Carling, David; Lelliott, Christopher; Gallego, Rosalía; Orešič, Matej; Chatterjee, Krishna; Saha, Asish K.; Rahmouni, Kamal; Diéguez, Carlos; Vidal-Puig, Antonio

    2010-01-01

    Thyroid hormones have widespread cellular effects; however it is unclear whether their effects on the central nervous system (CNS) contribute to global energy balance. Here, we demonstrate that either whole body hyperthyroidism or central administration of triiodothyronine (T3) decreases the activity of hypothalamic AMP-activated protein kinase (AMPK), increases sympathetic nervous system (SNS) activity and upregulates thermogenic markers in brown adipose tissue (BAT). Inhibition of the lipogenic pathway in the ventromedial nucleus of the hypothalamus (VMH) prevents CNS-mediated activation of BAT by thyroid hormone and reverses the weight loss associated with hyperthyroidism. Similarly inhibition of thyroid hormone receptors (TRs) in the VMH reverses the weight loss associated with hyperthyroidism. This regulatory mechanism depends on AMPK inactivation as genetic ablation of this enzyme in the VMH of euthyroid rats induces feeding-independent weight loss and increases expression of thermogenic markers in BAT. These effects are reversed by pharmacological blockade of the SNS. Thus, thyroid-hormone-induced modulation of AMPK activity and lipid metabolism in the hypothalamus is an important regulator of energy homeostasis. PMID:20802499

  5. A component of retinal light adaptation mediated by the thyroid hormone cascade.

    Science.gov (United States)

    Bedolla, Diana E; Torre, Vincent

    2011-01-01

    Analysis with DNA-microrrays and real time PCR show that several genes involved in the thyroid hormone cascade, such as deiodinase 2 and 3 (Dio2 and Dio3) are differentially regulated by the circadian clock and by changes of the ambient light. The expression level of Dio2 in adult rats (2-3 months of age) kept continuously in darkness is modulated by the circadian clock and is up-regulated by 2 fold at midday. When the diurnal ambient light was on, the expression level of Dio2 increased by 4-8 fold and a consequent increase of the related protein was detected around the nuclei of retinal photoreceptors and of neurons in inner and outer nuclear layers. The expression level of Dio3 had a different temporal pattern and was down-regulated by diurnal light. Our results suggest that DIO2 and DIO3 have a role not only in the developing retina but also in the adult retina and are powerfully regulated by light. As the thyroid hormone is a ligand-inducible transcription factor controlling the expression of several target genes, the transcriptional activation of Dio2 could be a novel genomic component of light adaptation.

  6. Free thyroid hormones in patients with severe non-thyroidal illness

    Energy Technology Data Exchange (ETDEWEB)

    Boettger, I.; Schneck, H.W.

    1985-11-01

    Free thyroid hormone radioligand assays and indirect methods for FT/sub 4/ and FT/sub 3/ were applied to measurement in sera of patients with severe NTI (hemodialysis, intensive-care, polytrauma). FT/sub 4/ by different techniques was low-normal to decreased by a kinetic two-tube and a T/sub 4/-analogue tracer single-tube assay whereas another two-tube technique measured normal to low-normal but in some instances increased FT/sub 4/ levels. Indirect parameters behaved in a similar fashion. FT/sub 3/ was decreased in most of the cases as were the indirect parameters, mostly due to affected T/sub 4/-T/sub 3/ conversion. Direct and indirect parameters for free thyroid hormones changed in parallel also during follow-up of NTI. There was no clear protein or albumen effect upon the two-tube FT/sub 4/ and the two-tube FT/sub 3/ assay(s). Supersensitively determined basal TSH was found to be decreased in some cases with severe NTI (polytrauma). The findings taken together are consistent with (pseudo) sedondary hypothyroidism in severe NTI. The data show the free thyroid hormone assays tested to be rather reliable with little or no disturbance by severe NTI or specifically hypoalbumenemia.

  7. Neurodevelopmental Consequences of Low-Level Thyroid Hormone Disruption Induced by Environmental Contaminants

    Science.gov (United States)

    Inadequate levels of thyroid hormone during critical developmental periods lead to stunted growth, mental retardation, and neurological 'cretinism'. Animal models of developmental thyroid hormone deficiency mirror well the impact of severe insults to the thyroid system. However, ...

  8. Pathophysiology of thyroid cancer

    International Nuclear Information System (INIS)

    Rajan, M.G.R.; Nadkarni, G.D.

    1999-01-01

    The main physiological function of the thyroid gland is to produce thyroid hormones. The primary physiological control over iodine transport, organification and hormone synthesis appears to be through thyroid stimulating hormone (TSH). Regulation of tumor cells, biochemical studies in experimental tumors, role of oxygen free radical and antioxidants, role of proteases in metastasis, influence of growth factors and influence of sex hormones and receptors are discussed

  9. Thyroid hormones: Possible roles in epilepsy pathology.

    Science.gov (United States)

    Tamijani, Seyedeh Masoumeh Seyedhoseini; Karimi, Benyamin; Amini, Elham; Golpich, Mojtaba; Dargahi, Leila; Ali, Raymond Azman; Ibrahim, Norlinah Mohamed; Mohamed, Zahurin; Ghasemi, Rasoul; Ahmadiani, Abolhassan

    2015-09-01

    Thyroid hormones (THs) L-thyroxine and L-triiodothyronine, primarily known as metabolism regulators, are tyrosine-derived hormones produced by the thyroid gland. They play an essential role in normal central nervous system development and physiological function. By binding to nuclear receptors and modulating gene expression, THs influence neuronal migration, differentiation, myelination, synaptogenesis and neurogenesis in developing and adult brains. Any uncorrected THs supply deficiency in early life may result in irreversible neurological and motor deficits. The development and function of GABAergic neurons as well as glutamatergic transmission are also affected by THs. Though the underlying molecular mechanisms still remain unknown, the effects of THs on inhibitory and excitatory neurons may affect brain seizure activity. The enduring predisposition of the brain to generate epileptic seizures leads to a complex chronic brain disorder known as epilepsy. Pathologically, epilepsy may be accompanied by mitochondrial dysfunction, oxidative stress and eventually dysregulation of excitatory glutamatergic and inhibitory GABAergic neurotransmission. Based on the latest evidence on the association between THs and epilepsy, we hypothesize that THs abnormalities may contribute to the pathogenesis of epilepsy. We also review gender differences and the presumed underlying mechanisms through which TH abnormalities may affect epilepsy here. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  10. Synergistic acceleration of thyroid hormone degradation by phenobarbital and the PPARα agonist WY14643 in rat hepatocytes

    International Nuclear Information System (INIS)

    Wieneke, N.; Neuschaefer-Rube, F.; Bode, L.M.; Kuna, M.; Andres, J.; Carnevali, L.C.; Hirsch-Ernst, K.I.; Pueschel, G.P.

    2009-01-01

    Energy balance is maintained by controlling both energy intake and energy expenditure. Thyroid hormones play a crucial role in regulating energy expenditure. Their levels are adjusted by a tight feedback-controlled regulation of thyroid hormone production/incretion and by their hepatic metabolism. Thyroid hormone degradation has previously been shown to be enhanced by treatment with phenobarbital or other antiepileptic drugs due to a CAR-dependent induction of phase II enzymes of xenobiotic metabolism. We have recently shown, that PPARα agonists synergize with phenobarbital to induce another prototypical CAR target gene, CYP2B1. Therefore, it was tested whether a PPARα agonist could enhance the phenobarbital-dependent acceleration of thyroid hormone elimination. In primary cultures of rat hepatocytes the apparent half-life of T3 was reduced after induction with a combination of phenobarbital and the PPARα agonist WY14643 to a larger extent than after induction with either compound alone. The synergistic reduction of the half-life could be attributed to a synergistic induction of CAR and the CAR target genes that code for enzymes and transporters involved in the hepatic elimination of T3, such as OATP1A1, OATP1A3, UGT1A3 and UGT1A10. The PPARα-dependent CAR induction and the subsequent induction of T3-eliminating enzymes might be of physiological significance for the fasting-induced reduction in energy expenditure by fatty acids as natural PPARα ligands. The synergism of the PPARα agonist WY14643 and phenobarbital in inducing thyroid hormone breakdown might serve as a paradigm for the synergistic disruption of endocrine control by other combinations of xenobiotics.

  11. Central regulation of the hypothalamo-pituitary-thyroid (HPT) axis: focus on clinical aspects.

    Science.gov (United States)

    Fliers, E; Boelen, A; van Trotsenburg, A S P

    2014-01-01

    The hypothalamus is the most prominent brain region involved in setpoint regulation of the thyroid axis. It generates the diurnal thyroid-stimulating hormone (TSH) rhythm, and it plays a central role in the adaptation of the thyroid axis to environmental factors such as caloric deprivation or infection. Many studies, including studies in human post-mortem tissue samples, have confirmed a key role for the thyrotropin-releasing hormone (TRH) neuron in the hypothalamic paraventricular nucleus (PVN) in thyroid axis regulation. In addition to their negative feedback action on TRH neurons in the hypothalamus, intrahypothalamic thyroid hormones can also modulate metabolism in adipose tissue and the liver via the autonomic nervous system. Congenital or acquired dysfunction of the hypothalamus or pituitary gland may result in central hypothyroidism (CeH). In the Netherlands, the prevalence of permanent congenital CeH as detected by neonatal screening is approximately 1 in 18000. In most neonates congenital CeH is accompanied by additional anterior pituitary hormone deficiencies, and many show clear morphological abnormalities such as a small anterior gland, a thin or absent pituitary stalk, or an ectopic posterior pituitary gland. Recently, a mutation in the immunoglobulin superfamily member 1 (IGSF1) gene was reported as a novel cause of X-linked, apparently isolated CeH occurring in neonates, children and adults. In adults, the most frequent cause of acquired CeH is a pituitary macroadenoma, usually accompanied by other pituitary hormone deficiencies. Central hyperthyroidism is a rare disorder, especially in children. In adults, it is mostly caused by a TSH-secreting pituitary adenoma. © 2014 Elsevier B.V. All rights reserved.

  12. The Hypercoagulable state in Hyperthyroidism is mediated via the Thyroid Hormone β Receptor pathway

    NARCIS (Netherlands)

    Elbers, Laura P. B.; Moran, Carla; Gerdes, Victor E. A.; van Zaane, Bregje; Meijers, Joost C. M.; Endert, Erik; Lyons, Greta; Chatterjee, V. Krishna; Bisschop, Peter H.; Fliers, Eric

    2016-01-01

    Hyperthyroidism is associated with a hypercoagulable state, but the underlying mechanism is unknown. Patients with resistance to thyroid hormone (RTH) due to defective thyroid hormone receptor β (TRβ) exhibit elevated circulating thyroid hormones (TH) with refractoriness to TH action in

  13. Radioimmunoassay for thyroid stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    1980-01-01

    An improved double antibody radioimmunoassay method is described for the determination of thyroid stimulating hormone (TSH) in biological and other fluids. Highly purified second antibody is immobilised on to hydrophilic, hydrolyzed polyacrylamide particles of a suspendable size to form a solid phase second antibody reagent. The immobilised second antibody reagent is used to precipitate the reaction product of the first antibody with labelled and unlabelled thyroid stimulating hormone (TSH-anti-TSH-complex) so as to produce a two-phase system which permits rapid and efficient separation of bound TSH in the solid phase from free TSH in the liquid phase. Details of the preparation of this novel second antibody-polyacrylamide reagent and of the assay procedure for human TSH are described. (U.K.)

  14. Epidermal growth factor (EGF) inhibits stimulated thyroid hormone secretion in the mouse

    International Nuclear Information System (INIS)

    Ahren, B.

    1987-01-01

    It is known that epidermal growth factor (EGF) inhibits iodide uptake in the thyroid follicular cells and lowers plasma levels of thyroid hormones upon infusion into sheep and ewes. In this study, the effects of EGF on basal and stimulated thyroid hormone secretion were investigated in the mouse. Mice were pretreated with 125 I and thyroxine; the subsequent release of 125 I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was not altered by intravenous injection of EGF (5 micrograms/animal). However, the radioiodine secretion stimulated by both TSH (120 microU/animal) and vasoactive intestinal peptide (VIP; 5 micrograms/animal) were inhibited by EGF (5 micrograms/animal). At a lower dose level (0.5 microgram/animal), EGF had no influence on stimulated radioiodine secretion. In conclusion, EGF inhibits stimulated thyroid hormone secretion in the mouse

  15. Thyroid hormones profile in students of Makerere College of Health ...

    African Journals Online (AJOL)

    Serum concentrations of thyroxine (T4), triiodothyronine (T3) and Thyroid Stimulating Hormone (TSH) are used to assess thyroid function. It is recommended that each laboratory or hospital should establish its own reference values of T4, T3 and TSH for their clients because these hormones vary with ethnicity, geographical ...

  16. A component of retinal light adaptation mediated by the thyroid hormone cascade.

    Directory of Open Access Journals (Sweden)

    Diana E Bedolla

    Full Text Available Analysis with DNA-microrrays and real time PCR show that several genes involved in the thyroid hormone cascade, such as deiodinase 2 and 3 (Dio2 and Dio3 are differentially regulated by the circadian clock and by changes of the ambient light. The expression level of Dio2 in adult rats (2-3 months of age kept continuously in darkness is modulated by the circadian clock and is up-regulated by 2 fold at midday. When the diurnal ambient light was on, the expression level of Dio2 increased by 4-8 fold and a consequent increase of the related protein was detected around the nuclei of retinal photoreceptors and of neurons in inner and outer nuclear layers. The expression level of Dio3 had a different temporal pattern and was down-regulated by diurnal light. Our results suggest that DIO2 and DIO3 have a role not only in the developing retina but also in the adult retina and are powerfully regulated by light. As the thyroid hormone is a ligand-inducible transcription factor controlling the expression of several target genes, the transcriptional activation of Dio2 could be a novel genomic component of light adaptation.

  17. The hippocampal formation: morphological changes induced by thyroid, gonadal and adrenal hormones.

    Science.gov (United States)

    Gould, E; Woolley, C S; McEwen, B S

    1991-01-01

    The hippocampal formation is of considerable interest due to its proposed role in a number of important functions, including learning and memory processes. Manipulations of thyroid, gonadal and adrenal hormones have been shown to influence hippocampal physiology as well as learning and memory. The cellular events which underlie these hormone-induced functional changes are largely unexplored. However, studies suggest that hormonal manipulations during development and in adulthood result in dramatic morphological changes within the hippocampal formation. Because neuronal physiology has been suggested to depend upon neuronal morphology, we have been determining the morphologic sensitivity of hippocampal neurons to thyroid and steroid hormones in an effort to elucidate possible structural mechanisms to account for differences in hippocampal function. In this review, hormone-induced structural changes in the developing and adult hippocampal formation are discussed, with particular emphasis on their functional relevance. Sex differences, as well as the developmental effects of thyroid hormone and glucocorticoids, are described. Moreover, the effects of ovarian steroids, thyroid hormone and glucocorticoids on neuronal morphology in the hippocampal formation of the adult rat are reviewed. These hormone-induced structural changes may account, at least in part, for previously reported hormone-induced changes in hippocampal function.

  18. Silent pituitary macroadenoma co-secreting growth hormone and thyroid stimulating hormone.

    Science.gov (United States)

    Sen, Orhan; Ertorer, M Eda; Aydin, M Volkan; Erdogan, Bulent; Altinors, Nur; Zorludemir, Suzan; Guvener, Nilgun

    2005-04-01

    Silent pituitary adenomas are a group of tumors showing heterogenous morphological features with no hormonal function observed clinically. To date no explanation has been provided as to why these tumors remain "silent". We report a case of a silent macroadenoma with both growth hormone (GH) and thyroid stimulating hormone (TSH) staining and secretion but with no clinical manifestations, in particular, the absence of features of acromegaly or hyperthyroidism. The relevant literature is reviewed.

  19. The role of intracellular thyroid hormone metabolism in innate immune cells

    NARCIS (Netherlands)

    van der Spek, A.H.

    2018-01-01

    Innate immune cells have recently been identified as important thyroid hormone target cells. This thesis studies the role of intracellular thyroid hormone metabolism in the function of neutrophils and macrophages, two essential cell types of the innate immune system. Neutrophils, monocytes and

  20. Thyroid Hormone Receptor Antagonists: From Environmental Pollution to Novel Small Molecules.

    Science.gov (United States)

    Mackenzie, Louise S

    2018-01-01

    Thyroid hormone receptors (TRs) are nuclear receptors which control transcription, and thereby have effects in all cells within the body. TRs are an important regulator in many basic physiological processes including development, growth, metabolism, and cardiac function. The hyperthyroid condition results from an over production of thyroid hormones resulting in a continual stimulation of thyroid receptors which is detrimental for the patient. Therapies for hyperthyroidism are available, but there is a need for new small molecules that act as TR antagonists to treat hyperthyroidism. Many compounds exhibit TR antagonism and are considered detrimental to health. Some drugs in the clinic (most importantly, amiodarone) and environmental pollution exhibit TR antagonist properties and thus have the potential to induce hypothyroidism in some people. This chapter provides an overview of novel small molecules that have been specifically designed or screened for their TR antagonist activity as novel treatments for hyperthyroidism. While novel compounds have been identified, to date none have been developed sufficiently to enter clinical trials. Furthermore, a discussion on other sources of TR antagonists is discussed in terms of side effects of current drugs in the clinic as well as environmental pollution. © 2018 Elsevier Inc. All rights reserved.

  1. Substances that disrupt thyroid hormone biosynthesis (in Romanian

    Directory of Open Access Journals (Sweden)

    Pap, Andreea

    2015-06-01

    Full Text Available Endocrine disrupters are natural or synthetic chemical substances that have the possibility to alter the endocrine functions leading to serious metabolic changes especially in newborns. The accumulation and persistence over long periods of time became a priority in terms of health and environment. The mechanism of action is represented by blocking, mimicking or modifying the effects of thyroid hormones. In this review, the main purpose was to determine what effects have the endocrine disruptors on the thyroid gland, especially on the thyroid hormone biosynthesis and setting the stage involved by it. We focused on the action of perchlorates, phthalates, BPC, PDPEs, soy, isoflavones, nitrates, thiocyanates, bisphenol A and triclorsan and came to the conclusion that their intervention can result in either hyperthyroidism or hypothyroidism.

  2. Influence of thyroid hormones on biochemical parameters of liver ...

    African Journals Online (AJOL)

    Normal level of thyroid hormones is important for normal hepatic function and thyroid dysfunction may modulate metabolic function of liver. The purpose of this study is to determine whether liver function is associated with subclinical and overt hypothyroidism. Thyroid and liver function tests were evaluated in 47 patients with ...

  3. Features of changes in concentration of pituitary thyroid hormone and thyroid hormones in the blood of two-month rats with experimental hypothyroidism before and after operations with N-(2-methoxybenzoyl)-O-isopropyl-α, β-dehydrothyrozine choline ester

    International Nuclear Information System (INIS)

    Khachatryan, T.S.; Topuzyan, V.O.

    2013-01-01

    The features of pituitary thyroid hormone concentration and thyroid hormones in the blood of rats with experimental hypothyroidism before and after injections of N-(2-methoxybenzoyl)-O-isopropyl-α, β-dehydrothyrozine choline ester were investigated. A sharp increase of pituitary thyroid hormone level and a sharp decrease of the level of thyroid hormones in the blood of two-month rats with hypothyroidism have been established. Under the action of N-(2-methoxybenzoyl)-O-isopropyl--α, β-dehydrothyrozine choline ester the decrease of pituitary thyroid hormone concentration and the increase of thyroid hormones level in the rats' blood have been observed and reached their values in intact animals

  4. Pre-operative ultrasound identification of thyroiditis helps predict the need for thyroid hormone replacement after thyroid lobectomy.

    Science.gov (United States)

    Morris, Lilah F; Iupe, Isabella M; Edeiken-Monroe, Beth S; Warneke, Carla L; Hansen, Mandy O; Evans, Douglas B; Lee, Jeffrey E; Grubbs, Elizabeth G; Perrier, Nancy D

    2013-01-01

    To evaluate whether pre-operative thyroiditis identified by ultrasound (US) could help predict the need for thyroid hormone replacement (THR) following thyroid lobectomy. Data from patients who underwent thyroid lobectomy in 2006-2011, were not taking THR pre-operatively, and had ≥1 month of follow-up were reviewed retrospectively. THR was prescribed for relatively elevated thyroid-stimulating hormone (TSH) and hypothyroid symptoms. The Kaplan-Meier method was used to estimate the percentage of patients who required THR at 6, 12, 18, and 24 months postoperatively, and Cox proportional hazards regression models were used to evaluate prognostic factors for requiring post-thyroid lobectomy THR. During follow-up, 45 of 98 patients required THR. Median follow-up among patients not requiring THR was 11.6 months (range, 1.2 to 51.3 months). Six months after thyroid lobectomy, 22% of patients were taking THR (95% confidence interval [CI], 15-32%); the proportion increased to 46% at 12 months (95% CI, 36-57%) and 55% at 18 months (95% CI, 43-67%). On univariate analysis, significant prognostic factors for postoperative THR included a pre-operative TSH level >2.5 μ international units [IU]/mL (hazard ratio [HR], 2.8; 95% CI, 1.4-5.5; P = .004) and pathology-identified thyroiditis (HR, 2.4; 95% CI, 1.3-4.3; P = .005). Patients with both pre-operative TSH >2.5 μIU/mL and US-identified thyroiditis had a 5.8-fold increased risk of requiring postoperative THR (95% CI, 2.4-13.9; P2.5 μIU/mL significantly increases the risk of requiring THR after thyroid lobectomy. Thyroiditis can add to that prediction and guide pre-operative patient counseling and surgical decision making. US-identified thyroiditis should be reported and post-thyroid lobectomy patients followed long-term (≥18 months).

  5. Targeting the thyroid gland with thyroid-stimulating hormone (TSH)-nanoliposomes.

    Science.gov (United States)

    Paolino, Donatella; Cosco, Donato; Gaspari, Marco; Celano, Marilena; Wolfram, Joy; Voce, Pasquale; Puxeddu, Efisio; Filetti, Sebastiano; Celia, Christian; Ferrari, Mauro; Russo, Diego; Fresta, Massimo

    2014-08-01

    Various tissue-specific antibodies have been attached to nanoparticles to obtain targeted delivery. In particular, nanodelivery systems with selectivity for breast, prostate and cancer tissue have been developed. Here, we have developed a nanodelivery system that targets the thyroid gland. Nanoliposomes have been conjugated to the thyroid-stimulating hormone (TSH), which binds to the TSH receptor (TSHr) on the surface of thyrocytes. The results indicate that the intracellular uptake of TSH-nanoliposomes is increased in cells expressing the TSHr. The accumulation of targeted nanoliposomes in the thyroid gland following intravenous injection was 3.5-fold higher in comparison to untargeted nanoliposomes. Furthermore, TSH-nanoliposomes encapsulated with gemcitabine showed improved anticancer efficacy in vitro and in a tumor model of follicular thyroid carcinoma. This drug delivery system could be used for the treatment of a broad spectrum of thyroid diseases to reduce side effects and improve therapeutic efficacy. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Resistance to thyroid hormone due to defective thyroid receptor alpha.

    Science.gov (United States)

    Moran, Carla; Chatterjee, Krishna

    2015-08-01

    Thyroid hormones act via nuclear receptors (TRα1, TRβ1, TRβ2) with differing tissue distribution; the role of α2 protein, derived from the same gene locus as TRα1, is unclear. Resistance to thyroid hormone alpha (RTHα) is characterised by tissue-specific hypothyroidism associated with near-normal thyroid function tests. Clinical features include dysmorphic facies, skeletal dysplasia (macrocephaly, epiphyseal dysgenesis), growth retardation, constipation, dyspraxia and intellectual deficit. Biochemical abnormalities include low/low-normal T4 and high/high-normal T3 concentrations, a subnormal T4/T3 ratio, variably reduced reverse T3, raised muscle creatine kinase and mild anaemia. The disorder is mediated by heterozygous, loss-of-function, mutations involving either TRα1 alone or both TRα1 and α2, with no discernible phenotype attributable to defective α2. Whole exome sequencing and diagnostic biomarkers may enable greater ascertainment of RTHα, which is important as thyroxine therapy reverses some metabolic abnormalities and improves growth, constipation, dyspraxia and wellbeing. The genetic and phenotypic heterogeneity of RTHα and its optimal management remain to be elucidated. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Metastatic Follicular Thyroid Carcinoma Secreting Thyroid Hormone and Radioiodine Avid without Stimulation: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Syed A. Abid

    2014-01-01

    Full Text Available Introduction. This is an extremely rare case of a patient with metastatic follicular thyroid cancer who continued to produce thyroid hormone and was iodine scan positive without stimulation after thyroidectomy and radioiodine (I-131 therapy. Patient Findings. A 76-year-old Caucasian male was diagnosed with metastatic follicular thyroid carcinoma on lung nodule biopsy. Total thyroidectomy was performed and he was ablated with 160 mCi of I-131 after recombinant human thyrotropin (rhTSH stimulation. Whole body scan (WBS after treatment showed uptake in bilateral lungs, right sacrum, and pelvis. The thyroglobulin decreased from 2,063 to 965 four months after treatment but rapidly increased to 2,506 eleven months after I-131. Thyroid stimulating hormone (TSH remained suppressed and free T4 remained elevated after I-131 therapy without thyroid hormone supplementation. He was treated with an additional 209 mCi with WBS findings positive in lung and pelvis. Despite I-131, new metastatic lesions were noted in the left thyroid bed and large destructive lesion to the first cervical vertebrae four months after the second I-131 dose. Conclusions. This case is exceptional because of its rarity and also due to the dissociation between tumor differentiation and aggressiveness. The metastatic lesions continued to secrete thyroid hormone and remained radioiodine avid with rapid progression after I-131 therapy.

  8. Chronic food restriction and the circadian rhythms of pituitary-adrenal hormones, growth hormone and thyroid-stimulating hormone.

    Science.gov (United States)

    Armario, A; Montero, J L; Jolin, T

    1987-01-01

    Adult male Sprague-Dawley rats were subjected to food restriction so that they ate 65% of food ingested by control rats. While control rats had free access to food over the 24-hour period, food-restricted rats were provided with food daily at 10 a.m. The experimental period lasted for 34 days. On day 35, rats from both experimental groups were killed at 08.00, 11.00, 14.00, 24.00 and 02.00 h. Food restriction modified the circadian rhythms of ACTH and corticosterone. In addition, total circulating corticosterone throughout the day was higher in food-restricted than in control rats. In contrast, food restriction resulted in depressed secretion of thyroid-stimulating hormone and growth hormone. The results indicate that time of food availability entrained circadian corticosterone rhythm but not thyroid-stimulating hormone and growth hormone rhythms.

  9. Thyroid hormone-like and estrogenic activity of hydroxylated PCBs in cell culture

    International Nuclear Information System (INIS)

    Kitamura, Shigeyuki; Jinno, Norimasa; Suzuki, Tomoharu; Sugihara, Kazumi; Ohta, Shigeru; Kuroki, Hiroaki; Fujimoto, Nariaki

    2005-01-01

    The thyroid hormone-disrupting activity of hydroxylated PCBs was examined. 4-Hydroxy-2,2',3,4',5,5'-hexachlorobiphenyl (4-OH-2,2',3,4',5,5'-HxCB), 4-hydroxy-3,3',4',5-tetrachlorobiphenyl (4-OH-3,3',4',5-TCB) and 4,4'-dihydroxy-3,3',5,5'-tetrachlorobiphenyl (4,4'-diOH-3,3',5,5'-TCB), which have been detected as metabolites of PCBs in animals and humans, and six other 4-hydroxylated PCBs markedly inhibited the binding of triiodothyronine (1 x 10 -10 M) to thyroid hormone receptor (TR) in the concentration range of 1 x 10 -6 to 1 x 10 -4 M. However, 4-hydroxy-2',4',6'-trichlorobiphenyl (4-OH-2',4',6'-TCB), 3-hydroxy-2,2',5,5'-tetrachlorobiphenyl, 4-hydroxy-2,2',5,5'-tetrachlorobiphenyl, 4-hydroxy-2,3,3',4'-tetrachlorobiphenyl, 2,3',5,5'-tetrachlorobiphenyl and 2,3',4',5,5'-pentachlorodiphenyl did not show affinity for TR. The thyroid hormonal activity of PCBs was also examined using rat pituitary cell line GH3 cells, which grow and release growth hormone in a thyroid hormone-dependent manner. 4-OH-2,2',3,4',5,5'-HxCB, 4,4'-diOH-3,3',5,5'-TCB and 4-OH-3,3',4',5-TCB enhanced the proliferation of GH3 cells and stimulated their production of growth hormone in the concentration range of 1 x 10 -7 to 1 x 10 -4 M, while PCBs which had no affinity for thyroid hormone receptor were inactive. In contrast, only 4-OH-2',4',6'-TCB exhibited a significant estrogenic activity using estrogen-responsive reporter assay in MCF-7 cells. However, the 3,5-dichloro substitution of 4-hydroxylated PCBs markedly decreased the estrogenic activity. These results suggest that, at least for the 17 PCB congeners and hydroxylated metabolites tested, a 4-hydroxyl group in PCBs is essential for thyroid hormonal and estrogenic activities, and that 3,5-dichloro substitution favors thyroid hormonal activity, but not estrogenic activity

  10. Thyroid hormones and carcinoembryonic antigen in persons with a high risk of lung cancer

    International Nuclear Information System (INIS)

    Svetukhina, E.S.; Bukhteeva, N.F.; Sapozhkova, L.P.; Maripova, Eh.M.

    1984-01-01

    An attempt was made to study CEA and thyroid hormones in high risk groups as there is evidence of their change in lung cancer patients. A questionnaire to distinguish between 4 types of the probability of lung cancer development and a method of radioimmunoassay to study the concentration of CEA and thyroid hormones in the blood serum were used. A high risk group included 320 practically healthy persons, a control group 108 patients with verified lung cancer. The results of the study have shown that the concentration of CEA and thyroid hormones increases more often in persons of the high risk group with noncancerous diseases than in persons without pathological pulmonary changes. With an increase in the degree of probability the frequency of a high concentration of CEA and thyroid hormones grows. The older the persons with a high risk of lung cancer, the higher the frequency of concentration of the thyroid hormones. Studies of CEA and thyroid hormones can be used for dynamic observation of persons with a high risk of lung cancer

  11. The chicken c-erbA alpha-product induces expression of thyroid hormone-responsive genes in 3,5,3'-triiodothyronine receptor-deficient rat hepatoma cells

    DEFF Research Database (Denmark)

    Muñoz, A; Höppner, W; Sap, J

    1990-01-01

    To determine the capacity of the chicken c-erbA (cTR-alpha) gene product in regulating expression of known thyroid hormone-responsive genes, both the cTR-alpha and the viral v-erbA genes were expressed in FAO cells, a rat hepatoma cell line defective for functional thyroid hormone receptors. Upon...

  12. Concentration of serum thyroid hormone binding proteins after 131I treatment of hyperthyroidism

    International Nuclear Information System (INIS)

    Harrop, J.S.; Hopton, M.R.; Lazarus, J.H.

    1981-01-01

    Serum concentrations of the thyroid hormone binding proteins, thyroxine binding globulin, prealbumin, and albumin were determined in 30 thyrotoxic patients before and after 131 I treatment. Each patient was placed into one of three groups according to response to treatment. The serum concentration of all three proteins rose significantly in 10 patients who became euthyroid, and a greater increase was seen in 10 patients who developed hypothyroidism. There was no significant change in thyroid hormone binding protein concentrations in 10 subjects who remained hyperthyroid. Changes in the concentration of thyroid hormone binding proteins should be borne in mind when total thyroid hormone concentrations are used to monitor the progress of patients receiving treatment for hyperthyroidism. (author)

  13. Changes in thyroid hormones in surgical trauma.

    Directory of Open Access Journals (Sweden)

    Arunabh

    1992-07-01

    Full Text Available A prospective study of 20 patients who underwent elective surgery, is presented reporting the effect of surgical trauma on circulating thyroid hormone levels. Although no increase in the serum T4 levels was observed following surgery, serum T3 values were found to decrease and serum rT3 values were found to increase in the post-operative period, representing activation of an alternate pathway in the peripheral conversion of T4 to T3. Since trauma induces a hypermetabolic state due to hypersecretion of cortisol, alterations in thyroid hormone levels were concluded to represent an appropriate response in trauma to counter the effects of trauma-induced cortisol hypersecretion.

  14. Perfluoroalkyl substances exposure and thyroid hormones in humans: epidemiological observations and implications

    Directory of Open Access Journals (Sweden)

    Jung Eun Lee

    2017-03-01

    Full Text Available Thyroid hormones play crucial roles in normal neurodevelopment of fetus and child. Many chemicals can affect control and homeostasis of thyroid hormones, and eventually lead to various adverse health effects including neurodevelopmental disorders. Perfluoroalkyl substances (PFASs are among the thyroid disrupting chemicals that can be encountered among general human population. Due to their unique physicochemical characteristics, PFASs have been used as surfactants and surface coating materials in many applications. Therefore, PFASs have been frequently detected in humans and environment worldwide. In cross-sectional studies using nationally representative general human populations of United States, several PFASs have shown significant associations with thyroid hormones. Moreover, among pregnant women and their infants, not only major PFASs such as perfluorooctane sulfonic acid and perfluorooctanoic acid, but also those with shorter or longer carbon chains showed significant associations with thyroid hormones. Often demographic characteristics such as sex, age, and disease status appear to influence the associations between PFASs exposure and thyroid hormones. In general, major PFASs showed hypothyroidism effects among pregnant women and infants. As 8 carbon based PFASs have been phased out, those with shorter or longer carbon chains have been used in growing amount as replacement. However, only limited information is available for their occurrences and toxicity among humans. Further investigations on these substituting PFASs are required. In addition, efforts are warranted to identify sources of and mitigate exposure to these thyroid disrupting chemicals especially during pregnancy and early stages of life.

  15. A case of myxedema coma caused by isolated thyrotropin stimulating hormone deficiency and Hashimoto's thyroiditis.

    Science.gov (United States)

    Iida, Keiji; Hino, Yasuhisa; Ohara, Takeshi; Chihara, Kazuo

    2011-01-01

    Myxedema coma (MC) is a rare, but often fatal endocrine emergency. The majority of cases that occur in elderly women with long-standing primary hypothyroidism are caused by particular triggers. Conversely, MC of central origin is extremely rare. Here, we report a case of MC with both central and primary origins. A 56-year-old woman was transferred to our hospital due to loss of consciousness; a chest x-ray demonstrated severe cardiomegaly. Low body temperature, bradycardia, and pericardial effusion suggested the presence of hypothyroidism. Endocrinological examination revealed undetectable levels of serum free thyroxine (T(4)) and free triiodothyronine (T(3)), whereas serum thyroid-stimulating hormone (TSH) levels were not elevated. The woman's serum anti-thyroid peroxidase antibody and anti-thyroglobulin antibody tests were positive, indicating that she had Hashimoto's thyroiditis. Provocative tests to the anterior pituitary revealed that she had TSH and growth hormone (GH) deficiency; however, GH levels were restored after supplementation with levothyroxine for 5 months. This was not only a rare case of MC with TSH deficiency and Hashimoto's thyroiditis; the patient also developed severe osteoporosis and possessed transient elevated levels of serum carcinoembryonic antigen (CEA). This atypical case may suggest the role of anterior pituitary hormone deficiencies, as well as hypothyroidism, in the regulation of bone metabolism.

  16. Thyroid Hormones and Moderate Exposure to Perchlorate during Pregnancy in Women in Southern California.

    Science.gov (United States)

    Steinmaus, Craig; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C; Miller, Mark D; Pearce, Elizabeth N; Valentin-Blasini, Liza; DeLorenze, Gerald; Hoofnagle, Andrew N; Liaw, Jane

    2016-06-01

    Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in the offspring. We evaluated the potential effects of low environmental exposures to perchlorate on thyroid function. Serum thyroid hormones and anti-thyroid antibodies and urinary perchlorate, thiocyanate, nitrate, and iodide concentrations were measured in 1,880 pregnant women from San Diego County, California, during 2000-2003, a period when much of the area's water supply was contaminated from an industrial plant with perchlorate at levels near the 2007 California regulatory standard of 6 μg/L. Linear regression was used to evaluate associations between urinary perchlorate and serum thyroid hormone concentrations in models adjusted for urinary creatinine and thiocyanate, maternal age and education, ethnicity, and gestational age at serum collection. The median urinary perchlorate concentration was 6.5 μg/L, about two times higher than in the general U.S. Adjusted associations were identified between increasing log10 perchlorate and decreasing total thyroxine (T4) [regression coefficient (β) = -0.70; 95% CI: -1.06, -0.34], decreasing free thyroxine (fT4) (β = -0.053; 95% CI: -0.092, -0.013), and increasing log10 thyroid-stimulating hormone (β = 0.071; 95% CI: 0.008, 0.133). These results suggest that environmental perchlorate exposures may affect thyroid hormone production during pregnancy. This could have implications for public health given widespread perchlorate exposure and the importance of thyroid hormone in fetal neurodevelopment. Steinmaus C, Pearl M, Kharrazi M, Blount BC, Miller MD, Pearce EN, Valentin-Blasini L, DeLorenze G, Hoofnagle AN, Liaw J. 2016. Thyroid

  17. Polybrominated diphenyl ethers (PBDEs) and thyroid hormones in cord blood

    International Nuclear Information System (INIS)

    Ding, Guodong; Yu, Jing; Chen, Limei; Wang, Caifeng; Zhou, Yijun; Hu, Yi; Shi, Rong; Zhang, Yan; Cui, Chang; Gao, Yu; Tian, Ying; Liu, Fang

    2017-01-01

    Human exposure to polybrominated diphenyl ethers (PBDEs) has been increasing over the last three decades in China and around the world. Animal studies suggest that PBDEs could reduce blood levels of thyroid hormones, but it is unclear whether PBDEs disrupt thyroid function in humans. We used data from a prospective birth cohort of 123 pregnant women who were enrolled between September 2010 and March 2011 in Shandong, China. We measured the concentrations of eight PBDE congeners (n = 106) and five thyroid hormones (n = 107) in cord serum samples. We examined the relationship between prenatal exposure to PBDEs and thyroid function (n = 90). Median concentrations of BDEs 47, 99, 100, and 153 (detection frequencies > 75%) were 3.96, 8.27, 3.31, and 1.89 ng/g lipid, respectively. A 10-fold increase in BDE-99 and Σ 4 PBDEs (the sum of BDEs 47, 99, 100, and 153) concentrations was associated with a 0.41 μg/dL (95% confidence interval [CI]: 0.10 to 0.72) and 0.37 μg/dL (95% CI: 0.06 to 0.68) increase in total thyroxine levels (TT 4 ), respectively. No associations were found between other individual congeners and any of the five thyroid hormones. Our study suggests that prenatal exposure to PBDEs may be associated with higher TT 4 in cord blood. Given the inconsistent findings across existing studies, our results need to be confirmed in additional studies. - Highlights: • Human exposure to PBDEs has been increased over recent decades in China. • PBDEs reduce thyroid hormones in animal studies, but it is unclear in humans. • We examined the relation of PBDE levels with thyroid hormones in cord blood. • Prenatal exposure to PBDEs is associated with higher total thyroxine levels. • The findings may have implications for fetal development. - Exposure to PBDEs is associated with higher total thyroxine levels in cord blood, and the findings may have implications for fetal development.

  18. SIRT1 Regulates Thyroid-Stimulating Hormone Release by Enhancing PIP5Kgamma Activity through Deacetylation of Specific Lysine Residues in Mammals.

    Directory of Open Access Journals (Sweden)

    Sayaka Akieda-Asai

    Full Text Available BACKGROUND: SIRT1, a NAD-dependent deacetylase, has diverse roles in a variety of organs such as regulation of endocrine function and metabolism. However, it remains to be addressed how it regulates hormone release there. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that SIRT1 is abundantly expressed in pituitary thyrotropes and regulates thyroid hormone secretion. Manipulation of SIRT1 level revealed that SIRT1 positively regulated the exocytosis of TSH-containing granules. Using LC/MS-based interactomics, phosphatidylinositol-4-phosphate 5-kinase (PIP5Kgamma was identified as a SIRT1 binding partner and deacetylation substrate. SIRT1 deacetylated two specific lysine residues (K265/K268 in PIP5Kgamma and enhanced PIP5Kgamma enzyme activity. SIRT1-mediated TSH secretion was abolished by PIP5Kgamma knockdown. SIRT1 knockdown decreased the levels of deacetylated PIP5Kgamma, PI(4,5P(2, and reduced the secretion of TSH from pituitary cells. These results were also observed in SIRT1-knockout mice. CONCLUSIONS/SIGNIFICANCE: Our findings indicated that the control of TSH release by the SIRT1-PIP5Kgamma pathway is important for regulating the metabolism of the whole body.

  19. Characterization of tissue metabolism of thyroid hormones in very premature infants

    International Nuclear Information System (INIS)

    Pavelka, S.; Kopecky, J.; Brauner, P.

    1998-01-01

    Thyroid status was characterized in very preterm infants (gestational age 23-32 wk; n = 61) from birth through day 14; in those infants who died within 16 days of delivery (n = 10) it was also correlated with the metabolism of thyroid hormones in peripheral tissues (brain, liver, kidney, skeletal muscle, and different localities of adipose tissue). The results obtained support the view that peripheral tissues of very premature infants are involved in local generation of triiodothyronine (T 3 ) and inactivation of thyroid hormones, but do not represent a major source of circulating T 3 . In this study observations on postnatal development of plasma thyroid hormone levels in normal and critically ill premature neonates are presented. Enzyme activities of all three types of iodothyronine deiodinases were followed in autopsy samples from brain, liver, kidney, muscle, and adipose tissue depots, to better characterize the relationships between peripheral metabolism of thyroid hormones and thyroid status in critically ill very preterm newborns. Plasma concentrations of total T 3 , total T 4 , and total rT 3 were estimated by competitive radioimmunoassay. Plasma TSH concentrations were measured by microparticle enzyme immunoassay. Measurable activities of deiodinases of type I, II and II were detected post mortem in all tissue samples, except for type II activity in kidney. No correlation between postnatal age and the enzyme activities was found in in different tissues in the group of infants who died by 16 days of age. All activities were the highest in liver and differed significantly in particular tissues. Obtained results suggest tat, in contrast to adults, iodothyronine metabolism in peripheral tissues of premature newborns seems to be dominated by thyroid hormones inactivation, and T 3 production mainly for local use inside tissues. (authors)

  20. Relational Stability of Thyroid Hormones in Euthyroid Subjects and Patients with Autoimmune Thyroid Disease

    Science.gov (United States)

    Hoermann, Rudolf; Midgley, John E.M.; Larisch, Rolf; Dietrich, Johannes W.

    2016-01-01

    Background/Aim Operating far from its equilibrium resting point, the thyroid gland requires stimulation via feedback-controlled pituitary thyrotropin (TSH) secretion to maintain adequate hormone supply. We explored and defined variations in the expression of control mechanisms and physiological responses across the euthyroid reference range. Methods We analyzed the relational equilibria between thyroid parameters defining thyroid production and thyroid conversion in a group of 271 thyroid-healthy subjects and 86 untreated patients with thyroid autoimmune disease. Results In the euthyroid controls, the FT3-FT4 (free triiodothyronine-free thyroxine) ratio was strongly associated with the FT4-TSH ratio (tau = −0.22, p < 0.001, even after correcting for spurious correlation), linking T4 to T3 conversion with TSH-standardized T4 production. Using a homeostatic model, we estimated both global deiodinase activity and maximum thyroid capacity. Both parameters were nonlinearly and inversely associated, trending in opposite directions across the euthyroid reference range. Within the panel of controls, the subgroup with a relatively lower thyroid capacity (<2.5 pmol/s) displayed lower FT4 levels, but maintained FT3 at the same concentrations as patients with higher functional and anatomical capacity. The relationships were preserved when extended to the subclinical range in the diseased sample. Conclusion The euthyroid panel does not follow a homogeneous pattern to produce random variation among thyroid hormones and TSH, but forms a heterogeneous group that progressively displays distinctly different levels of homeostatic control across the euthyroid range. This suggests a concept of relational stability with implications for definition of euthyroidism and disease classification. PMID:27843807

  1. The effect of thyroid hormone on haemostasis and thrombosis

    NARCIS (Netherlands)

    Debeij, Jan

    2014-01-01

    In this thesis the relation between thyroid hormones and the coagulation system will be examined. As an introduction, the hypothalamic-pituitary-thyroid axis, the coagulation system and their interactions will be discussed. A short overview of the literature preceding the research reported in this

  2. Persistent Graves' hyperthyroidism despite rapid negative conversion of thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results: a case report.

    Science.gov (United States)

    Ohara, Nobumasa; Kaneko, Masanori; Kitazawa, Masaru; Uemura, Yasuyuki; Minagawa, Shinichi; Miyakoshi, Masashi; Kaneko, Kenzo; Kamoi, Kyuzi

    2017-02-06

    Graves' disease is an autoimmune thyroid disorder characterized by hyperthyroidism, and patients exhibit thyroid-stimulating hormone receptor antibody. The major methods of measuring circulating thyroid-stimulating hormone receptor antibody include the thyroid-stimulating hormone-binding inhibitory immunoglobulin assays. Although the diagnostic accuracy of these assays has been improved, a minority of patients with Graves' disease test negative even on second-generation and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulins. We report a rare case of a thyroid-stimulating hormone-binding inhibitory immunoglobulin-positive patient with Graves' disease who showed rapid lowering of thyroid-stimulating hormone-binding inhibitory immunoglobulin levels following administration of the anti-thyroid drug thiamazole, but still experienced Graves' hyperthyroidism. A 45-year-old Japanese man presented with severe hyperthyroidism (serum free triiodothyronine >25.0 pg/mL; reference range 1.7 to 3.7 pg/mL) and tested weakly positive for thyroid-stimulating hormone-binding inhibitory immunoglobulins on second-generation tests (2.1 IU/L; reference range hyperthyroidism for more than 8 years, requiring 15 mg/day of thiamazole to correct. During that period, he tested negative on all first-generation, second-generation, and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, but thyroid scintigraphy revealed diffuse and increased uptake, and thyroid ultrasound and color flow Doppler imaging showed typical findings of Graves' hyperthyroidism. The possible explanations for serial changes in the thyroid-stimulating hormone-binding inhibitory immunoglobulin results in our patient include the presence of thyroid-stimulating hormone receptor antibody, which is bioactive but less reactive on thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, or the effect of reduced levels of circulating thyroid

  3. Relationship between thyroid functions and urinary growth hormone secretion in patients with hyper- and hypothyroidism.

    Science.gov (United States)

    Murao, K; Takahara, J; Sato, M; Tamaki, M; Niimi, M; Ishida, T

    1994-10-01

    Thyroid hormone plays an important role in growth hormone (GH) synthesis and secretion. To study the relationship between thyroid function and urinary GH secretion in the hyperthyroid and hypothyroid states, we measured thyroid hormones, simultaneously with serum and urinary GH levels, in 54 patients with thyroid diseases. GH-releasing hormone (GRH) test was performed in 18 patients in order to evaluate serum and urinary GH responses to GRH in hyper- and hypothyroid states. Serum thyroid hormone levels were strongly correlated with the urinary GH levels in the patients, and the correlation was greater than that between serum thyroid hormone and serum GH levels. Urinary GH levels were significantly higher in the hyperthyroid patients than in the euthyroid and hypothyroid patients, although serum GH levels were not significantly different among these three groups. Serum GH response to GRH was significantly decreased in hyperthyroid patients as compared to euthyroid patients. However, urinary GH levels after GRH administration were not decreased in the hyperthyroid patients. These results suggest that hyperthyroid states increase GH in urine and may accelerate the urinary clearance of GH.

  4. Optimized FPGA Implementation of the Thyroid Hormone Secretion Mechanism Using CAD Tools.

    Science.gov (United States)

    Alghazo, Jaafar M

    2017-02-01

    The goal of this paper is to implement the secretion mechanism of the Thyroid Hormone (TH) based on bio-mathematical differential eqs. (DE) on an FPGA chip. Hardware Descriptive Language (HDL) is used to develop a behavioral model of the mechanism derived from the DE. The Thyroid Hormone secretion mechanism is simulated with the interaction of the related stimulating and inhibiting hormones. Synthesis of the simulation is done with the aid of CAD tools and downloaded on a Field Programmable Gate Arrays (FPGAs) Chip. The chip output shows identical behavior to that of the designed algorithm through simulation. It is concluded that the chip mimics the Thyroid Hormone secretion mechanism. The chip, operating in real-time, is computer-independent stand-alone system.

  5. Molecular mechanisms of regulation of growth hormone gene expression in cultured rat pituitary cells by thyroid and glucocorticoid hormones

    International Nuclear Information System (INIS)

    Yaffe, B.M.

    1989-01-01

    In cultured GC cells, a rat pituitary tumor cell line, growth hormone [GH] is induced in a synergistic fashion by physiologic concentrations of thyroid and glucocorticoid hormones. Abundant evidence indicates that these hormones mediate this response via their specific receptors. The purpose of this thesis is to explore the mechanisms by which these hormones affect GH production. When poly (A) + RNA was isolated from cells grown both with and without hormones and translated in a cell-free wheat germ system, the preGH translation products were shown to be proportional to immunoassayable GH production under all combinations of hormonal milieux, indicating that changes in GH production is modulated at a pretranslational level. A cDNA library was constructed from poly (A) + RNA and one clone containing GH cDNA sequences was isolated. This was used to confirm the above results by Northern dot blot analysis. This probe was also used to assess hormonal effects on GH mRNA half-life and synthetic rates as well as GH gene transcription rates in isolated nuclei. Using a pulse-chase protocol in which cellular RNA was labeled in vivo with [ 3 H]uridine, and quantitating [ 3 H]GHmRNA directly by hybridization to GH cDNA bound to nitrocellulose filters, GHmRNA was found to have a half-life of approximately 50 hours, and was not significantly altered by the presence of inducing hormones

  6. A newly development RIA for thyroid hormone autoantibodies (THAAb)

    International Nuclear Information System (INIS)

    Li Fengying; Gu Liqiong; Chen Xiayin; Jin Yan; Chen Shuxian; Zhang Qun; Qiu Hongxia; Yang Jingren; Zhao Yongju; Chen Mingdao

    2004-01-01

    Objective: To report a newly developed RIA for THAAb from this laboratory. Methods: The tested serum samples were cultured with labelled thyroid hormone analogous ( 125 I T 3 , 125 I T 4 ) for 16 hours. Antigen-antibody complex was precipitated with anti-human IgG (immune precipitation method) and radio-activity determined. Results: The mean positive rate of THAAb in healthy euthyroid controls (n=186) was only 1.07%. The mean positive rate in patients with thyroid disorders was 14.4% (mean rate 13.5% in hyperthyroid subjects, n=118 and mean rate 15.2% in hypothyroid subjects, n=72). The serum THAAb titer could be markedly lowered after adding non-labelled thyroid hormones (P 3 and FT 4 would be significantly lowered (P 3 , FT 4 levels. In patients with positive THAAb (about 14.4% in patients with all thyroid disorders), the FT 3 , FT 4 levels were best determined after PEG precipitation. (authors)

  7. Inhibition of the thyroid hormone pathway in Xenopus laevis by 2-mercaptobenzothiazole

    International Nuclear Information System (INIS)

    Tietge, Joseph E.; Degitz, Sigmund J.; Haselman, Jonathan T.; Butterworth, Brian C.; Korte, Joseph J.; Kosian, Patricia A.; Lindberg-Livingston, Annelie J.

    2013-01-01

    Determining the effects of chemicals on the thyroid system is an important aspect of evaluating chemical safety from an endocrine disrupter perspective. Since there are numerous chemicals to test and limited resources, prioritizing chemicals for subsequent in vivo testing is critical. 2-Mercaptobenzothiazole (MBT), a high production volume chemical, was tested and shown to inhibit thyroid peroxidase (TPO) enzyme activity in vitro, a key enzyme necessary for the synthesis of thyroid hormone. To determine the thyroid disrupting activity of MBT in vivo, Xenopus laevis larvae were exposed using 7- and 21-day protocols. The 7-day protocol used 18–357 μg/L MBT concentrations and evaluated: metamorphic development, thyroid histology, circulating T4, circulating thyroid stimulating hormone, thyroidal sodium-iodide symporter gene expression, and thyroidal T4, T3, and related iodo-amino acids. The 21-day protocol used 23–435 μg/L MBT concentrations and evaluated metamorphic development and thyroid histology. Both protocols demonstrated that MBT is a thyroid disrupting chemical at the lowest concentrations tested. These studies complement the in vitro study used to identify MBT as a high priority for in vivo testing, supporting the utility/predictive potential of a tiered approach to testing chemicals for TPO activity inhibition. The 7-day study, with more comprehensive, sensitive, and diagnostic endpoints, provides information at intermediate biological levels that enables linking various endpoints in a robust and integrated pathway for thyroid hormone disruption associated with TPO inhibition.

  8. Maintaining Euthyroidism: Fundamentals of Thyroid Hormone ...

    African Journals Online (AJOL)

    While illnesses related to aberrant thyroid hormone homeostasis are the most prevalent endocrinological ..... The active catalytic center of D1, D2, and D3 contains the amino acid ..... educed appetite; impaired protein metabolism; reduced glucose deposition ..... insulin resistance in patients with type 2 diabetes mellitus.

  9. Thyroid hormone concentrations in dialysate during hemodialysis in children

    International Nuclear Information System (INIS)

    Waters, W.; Bulla, M.; Buschsieweke, U.; Kutzim, H.; Koeln Univ.

    1981-01-01

    Thyroxine (T4) concentration in dialysate in the course of hemodialysis was determined in 15 children. Concentrations were measured by a modified radioimmunoassay. During hemodialysis there was a slight increase in T4 concentration. At the end of hemodialysis T4 concentration was about 50% higher than soon after the onset of hemodialysis. The loss of T4 into dialysate during hemodialysis was 19.2 μg; the loss of T3 was less than 75 ng. The amount of the daily loss of thyroid hormones into dialysate was found to be in the range of normal urinary excretion. The lowering of serum thyroid hormone concentrations in children on hemodialysis cannot be explained by the loss of these hormones into dialysate. (orig.) [de

  10. Suppression of Thyroid Hormone Receptor-Mediated Transcription ...

    African Journals Online (AJOL)

    TH)-induced TR-mediated transcription. We further examined the effects of methamidophos on TR-thyroid hormone response element (TRE) binding using the liquid chemiluminescent DNA pull-down assay (LCDPA), and found no dissociation of ...

  11. Variation of left heart function and thyroid hormone in cirrhosis

    International Nuclear Information System (INIS)

    Liu Junchi; Du Sujun; Mao Shaorong; Lu Jun; Tang Xiaoling

    1996-01-01

    The observation of 52 cases of cirrhosis left heart function indices traced with 113 In m in quiet and motion, and the combining determination of thyroid hormone serum levels with RIA are described. The cirrhosis to the function of liver damage increased, the indices of left heart function has great change. Moreover, the serum levels of T 3 , FT 3 in thyroid hormone are decreased obviously and the serum level of rT 3 is also increased significantly

  12. Thyroid Stimulating Hormone Resistance Syndrome – A Case Report

    Directory of Open Access Journals (Sweden)

    SM Ashrafuzzaman

    2014-01-01

    Full Text Available Resistance to thyrotropin or thyroid stimulating hormone (RTSH can be defined as decreased responsiveness to thyroid stimulating hormone (TSH characterized by high TSH with normal but occasionally low T4 and T3 usually in absence of goiter or ectopic thyroid. It can be diagnosed when TSH is >30 mIU/L but free T4 (FT4 is within normal limit. Patient usually presents in euthyroid state with abnormally high TSH but may also present with mild to overt hypothyroidism. The precise prevalence is not known, but 20-30% infants may show transient mild RTSH. In adults it is rare. Here we report a case of RTSH in which a 19 years old young girl presented in euthyroid state with mild goiter. Ibrahim Med. Coll. J. 2014; 8(1: 32-33

  13. Corticotropin-releasing hormone: Mediator of vertebrate life stage transitions?

    Science.gov (United States)

    Watanabe, Yugo; Grommen, Sylvia V H; De Groef, Bert

    2016-03-01

    Hormones, particularly thyroid hormones and corticosteroids, play critical roles in vertebrate life stage transitions such as amphibian metamorphosis, hatching in precocial birds, and smoltification in salmonids. Since they synergistically regulate several metabolic and developmental processes that accompany vertebrate life stage transitions, the existence of extensive cross-communication between the adrenal/interrenal and thyroidal axes is not surprising. Synergies of corticosteroids and thyroid hormones are based on effects at the level of tissue hormone sensitivity and gene regulation. In addition, in representative nonmammalian vertebrates, corticotropin-releasing hormone (CRH) stimulates hypophyseal thyrotropin secretion, and thus functions as a common regulator of both the adrenal/interrenal and thyroidal axes to release corticosteroids and thyroid hormones. The dual function of CRH has been speculated to control or affect the timing of vertebrate life history transitions across taxa. After a brief overview of recent insights in the molecular mechanisms behind the synergic actions of thyroid hormones and corticosteroids during life stage transitions, this review examines the evidence for a possible role of CRH in controlling vertebrate life stage transitions. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The role of polyhalogenated aromatic hydrocarbons on thyroid hormone disruption and cognitive function: a review.

    Science.gov (United States)

    Builee, T L; Hatherill, J R

    2004-11-01

    Thyroid hormones (TH) are essential to normal brain development, influencing behavior and cognitive function in both adult and children. It is suggested that conditions found in TH abnormalities such as hypothyroidism, hyperthyroidism and generalized resistance to thyroid hormone (GRTH) share symptomatic behavioral impulses found in cases of attention deficit hyperactivity disorder (ADHD) and other cognitive disorders. Disrupters of TH are various and prevalent in the environment. This paper reviews the mechanisms of TH disruption caused by the general class of polyhalogenated aromatic hydrocarbons (PHAH)'s acting as thyroid disrupters (TD). PHAHs influence the hypothalamus-pituitary-thyroid (HPT) axis, as mimicry agents affecting synthesis and secretion of TH. Exposure to PHAH induces liver microsomal enzymes UDP-glucuronosyltransferase (UGT) resulting in accelerated clearance of TH. PHAHs can compromise function of transport and receptor binding proteins such as transthyretin and aryl hydrocarbon receptors (Ahr). Glucose metabolism and catecholamine synthesis are disrupted in the brain by the presence of PHAH. Further, PHAH can alter brain growth and development by perturbing cytoskeletal formation, thereby affecting neuronal migration, elongation and branching. The complex relationships between PHAH and cognitive function are examined in regard to the disruption of T4 regulation in the hypothalamus-pituitary-thyroid axis, blood, brain, neurons, liver and pre and postnatal development.

  15. A Component of Retinal Light Adaptation Mediated by the Thyroid Hormone Cascade

    OpenAIRE

    Bedolla, Diana E.; Torre, Vincent

    2011-01-01

    Analysis with DNA-microrrays and real time PCR show that several genes involved in the thyroid hormone cascade, such as deiodinase 2 and 3 (Dio2 and Dio3) are differentially regulated by the circadian clock and by changes of the ambient light. The expression level of Dio2 in adult rats (2-3 months of age) kept continuously in darkness is modulated by the circadian clock and is up-regulated by 2 fold at midday. When the diurnal ambient light was on, the expression level of Dio2 increased by 4-...

  16. The axolotl (Ambystoma mexicanum), a neotenic amphibian, expresses functional thyroid hormone receptors.

    Science.gov (United States)

    Safi, Rachid; Bertrand, Stéphanie; Marchand, Oriane; Duffraisse, Marilyne; de Luze, Amaury; Vanacker, Jean-Marc; Maraninchi, Marie; Margotat, Alain; Demeneix, Barbara; Laudet, Vincent

    2004-02-01

    Neotenic amphibians such as the axolotl (Ambystoma mexicanum) are often unable to undergo metamorphosis under natural conditions. It is thought that neoteny represents a deviation from the standard course of amphibian ontogeny, affecting the thyroid axis at different levels from the central nervous system to peripheral organs. Thyroid hormone receptors (TRs) that bind the thyroid hormone (TH) T(3) have been described in axolotl. However, the full sequences of TR were needed to better characterize the TH response and to be able to assess their functional capacity at the molecular level. We report that each of the alpha and beta axolotl TRs bind both DNA and TH, and they activate transcription in response to TH in a mammalian cell-based transient transfection assay. Moreover, both TRs are expressed in axolotl tissues. Interestingly, each TR gene generates alternatively spliced isoforms, harboring partial or total deletions of the ligand-binding domain, which are expressed in vivo. Further, we found that in the axolotl, TH regulates the expression of stromelysin 3 and collagenase 3, which are TH target genes in Xenopus. Taken together, these results suggest that axolotl TRs are functional and that the molecular basis of neoteny in the axolotl is not linked to a major defect in TH response in peripheral tissues.

  17. Inhibition of the Thyroid Hormone Pathway in Xenopus by Mercaptobenzothiazole

    Science.gov (United States)

    Amphibian metamorphosis is a thyroid hormone-dependent process that provides a potential model system to assess chemicals for their ability to disrupt the hypothalamic-pituitary-thyroid (HPT) axis. Several studies have demonstrated the sensitivity of this system to a variety of ...

  18. Expansion of microsatellite in the thyroid hormone receptor-alpha1 gene linked to increased receptor expression and less aggressive thyroid cancer

    DEFF Research Database (Denmark)

    Onda, Masamitsu; Li, Daisy; Suzuki, Shinichi

    2002-01-01

    PURPOSE: The purpose of this study was to determine whether the length of the THRA1 microsatellite, which resides in a noncoding portion of the thyroid hormone receptor-alpha1 gene, affects receptor expression and is linked to clinicopathological parameters in thyroid cancer. EXPERIMENTAL DESIGN......: In 30 cases of surgically resected sporadic thyroid cancer, the length of the THRA1 microsatellite was determined by DNA sequence analysis, and expression of thyroid hormone receptor-alpha1 was assessed immunohistochemically in thin sections cut from tumor blocks. The length of THRA1 and expression...... of thyroid hormone receptor-alpha1 were also assessed in seven cancer cell lines. Regression analysis was used to gauge the correlation between the size of THRA1 and receptor expression. Multivariate analysis was used to test for links to the clinical parameters of gender, age, histology, stage, nodal...

  19. Alterations of serum concentrations of thyroid hormones and sex hormone-binding globulin, nuclear binding of tri-iodothyronine and thyroid hormone-stimulated cellular uptake of oxygen and glucose in mononuclear blood cells from patients with non-thyroidal illness

    DEFF Research Database (Denmark)

    Kvetny, J; Matzen, L

    1990-01-01

    Nuclear tri-iodothyronine (T3) binding and thyroid hormone-stimulated oxygen consumption and glucose uptake were examined in mononuclear blood cells from patients with non-thyroidal illness (NTI) in which serum T3 was significantly (P less than 0.05) depressed (0.62 +/- 0.12 (S.D.) nmol/l) compared...

  20. Effects of thyroid hormones on cartilage sulphation in sex-linked dwarf chickens

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, S.; Wakita, M.; Kobayashi, Y. (Faculty of Bioresources, Mie University, Tsu (Japan)); Kakegawa, T.; Suzuki, M. (Institute of Endocrinology, Gunma University, Maebashi (Japan))

    1989-01-01

    The present investigation was undertaken to see if exogenous thyroid hormone could stimulate cartilage sulphation in vivo and in vitro in sex-linked dwarf chickens. L-thyroxine or L-3,5,3'-triiodothyronine injection for 7 consecutive days stimulated in vivo /sup 35/SO/sub 4//sup 2-/ incorporation into trachea cartilages of the dwarf chicken. Both thyroid hormones added to the incubation medium with or without 2,5% dwarf chicken serum also stimulated in vitro /sup 35/SO/sub 4//sup 2-/ incorporation into pelvic rudiment from 11-day chick embryos. These data demonstrate that thyroid hormones, like insulin-like growth factor I, might be responsible for the reduced growth rate of dwarf chickens. (author).

  1. Internal and external quality control in the determinations of the thyroid hormones

    International Nuclear Information System (INIS)

    Rodriguez, S.; Richmond, M.; Gonzalez, L.; Saenz, E.

    1990-01-01

    An evaluation of the thyroid hormone level in young adults and the results of an External Quality Control (EQC) for the thyroid related hormones: Thyroxine (T4), Triidothyronine (T3) and Thyroid Stinulating Hormone (TSH) are presented for Costa Rica. Hormone level in the 1053 sera evaluated range 0,2 to 3,52 nmol/1, from 43 to 207 nmol/1, and from 0 to 6,2 uUl/ml, for the nine radioimmunoassay laboratories that participated in the EQC. The mean variability among laboratories was 19.3%, 18% and 20.5% for T3, T4 and TSH, respectively. The Internal Quality Control (IQC) in the reference laboratory (immunoassay, INCIENSA) showed a mean variability of 5.6%, 6.22% and 6.93% for T3, T4 and TSH, respectively. (author). 19 refs, 4 figs

  2. The Possible Effect Of Tamoxifen Vs Whole Body Irradiation Treatment On Thyroid Hormones in Female Rats Bearing Mammary Tumors Chemically Induced

    International Nuclear Information System (INIS)

    Abdelgawad, M.R.

    2012-01-01

    Breast cancer is the most common malignancy among women in most developed and developing regions of the world. In women, this drug has tissuespecific effects, acting as an estrogen antagonist on the breast, and as an estrogen agonist on bone, lipid metabolism (increasing high-density lipoprotein cholesterol and decreasing low-density lipoprotein cholesterol), and the endometrium. Thyroid hormones act on almost all organs throughout the body and regulate the basal metabolism of the organism. Thyroid hormone can also stimulate the proliferation in vitro of certain tumor cell lines. The aim of the present study is to evaluate the significant value of tamoxifen and/or irradiation treatment on thyroid hormones in breast cancer bearing female rats. Forty two female Sprague-Dawely rats randomly divided into seven groups and the effect of tamoxifen and post-irradiation was studied on breast cancer chemically induced. The results shows a T 4 and estradiol levels not T 3 were altered in different experimental groups. It could be concluded that irradiation-induced changes in the composition of the mammary microenvironment promote the expression of neoplastic potential by affecting both estradiol and thyroid hormones, and tamoxifen may alter the thyroid hormones. Irradiation and tamoxifen administration may have worth effects on T 4 and estradiol levels and it is recommended to further studies towards the bystander effect of radiation and tamoxifen on the tissue culture and molecular biology scale.

  3. Diagnostic significance of the serum thyroid hormone indicies in various thyroid diseases

    International Nuclear Information System (INIS)

    Han, B.H.; Ko, S.M.; Yoon, S.R.; Ro, H.K.

    1980-01-01

    In an attempt to evaluate the diagnostic significance of the serum thyroid hormones in various thyroid function states, the author measured serum T 3 uptake, serum T 3 , serum T 4 , serum free T 4 and free T 4 index in 27 cases of normal subjects, 11 cases of hypothyroidism, 152 cases of euthyroidism and 81 cases of hyperthyroidism by the radioimmunoassay method. The results were as follows: 1) The ranges of serum thyroid hormones in normal subjects were, serum T 3 uptake; 27.4-42.1%, serum T 3 ; 93-245 ng/dl, serum T 4 ; 4.08-12.9 ng/dl and serum free T 4 ; 0.57-1.53 ng/dl (M+-2 S.D.). 2) Free T 4 index and serum T 4 show relatively high diagnostic value in euthyroidism group, and serum T 3 and T 4 in hypothyroidism group, while serum T 3 , free T 4 and T 4 show relatively high diagnostic value in hyperthyroidism group. 3) There were significant correlation between free T 4 index and serum T 4 (r=0.68) and between free T 4 index and serum free T 4 (r=0.67) in hyperthyroidism group. (author)

  4. Thyroid hormone treatment among pregnant women with subclinical hypothyroidism: US national assessment.

    Science.gov (United States)

    Maraka, Spyridoula; Mwangi, Raphael; McCoy, Rozalina G; Yao, Xiaoxi; Sangaralingham, Lindsey R; Singh Ospina, Naykky M; O'Keeffe, Derek T; De Ycaza, Ana E Espinosa; Rodriguez-Gutierrez, Rene; Coddington, Charles C; Stan, Marius N; Brito, Juan P; Montori, Victor M

    2017-01-25

     To estimate the effectiveness and safety of thyroid hormone treatment among pregnant women with subclinical hypothyroidism.  Retrospective cohort study.  Large US administrative database between 1 January 2010 and 31 December 2014.  5405 pregnant women with subclinical hypothyroidism, defined as untreated thyroid stimulating hormone (TSH) concentration 2.5-10 mIU/L.  Thyroid hormone therapy.  Pregnancy loss and other pre-specified maternal and fetal pregnancy related adverse outcomes.  Among 5405 pregnant women with subclinical hypothyroidism, 843 with a mean pre-treatment TSH concentration of 4.8 (SD 1.7) mIU/L were treated with thyroid hormone and 4562 with a mean baseline TSH concentration of 3.3 (SD 0.9) mIU/L were not treated (Ptreatment TSH concentration was 4.1-10 mIU/L (odds ratio 0.45, 0.30 to 0.65) but not if it was 2.5-4.0 mIU/L (0.91, 0.65 to 1.23) (Ptreatment was associated with decreased risk of pregnancy loss among women with subclinical hypothyroidism, especially those with pre-treatment TSH concentrations of 4.1-10 mIU/L. However, the increased risk of other pregnancy related adverse outcomes calls for additional studies evaluating the safety of thyroid hormone treatment in this patient population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Thyroid hormone receptor inhibits hepatoma cell migration through transcriptional activation of Dickkopf 4

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Hsiang-Cheng; Liao, Chen-Hsin [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China); Huang, Ya-Hui [Medical Research Central, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC (China); Wu, Sheng-Ming; Tsai, Chung-Ying; Liao, Chia-Jung; Tseng, Yi-Hsin; Lin, Yang-Hsiang; Chen, Cheng-Yi; Chung, I-Hsiao; Wu, Tzu-I [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China); Chen, Wei-Jan [First Cardiovascular Division, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC (China); Lin, Kwang-Huei, E-mail: khlin@mail.cgu.edu.tw [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China)

    2013-09-13

    Highlights: •T{sub 3} affects DKK4 mRNA and protein expression in HepG2-TR cells. •Regulation of DKK4 by T{sub 3} is at transcriptional level. •DKK4 overexpression suppresses hepatoma cell metastasis. -- Abstract: Triiodothyronine (T{sub 3}) is a potent form of thyroid hormone mediates several physiological processes including cellular growth, development, and differentiation via binding to the nuclear thyroid hormone receptor (TR). Recent studies have demonstrated critical roles of T{sub 3}/TR in tumor progression. Moreover, long-term hypothyroidism appears to be associated with the incidence of human hepatocellular carcinoma (HCC), independent of other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein that antagonizes the canonical Wnt signaling pathway, is induced by T{sub 3} at both mRNA and protein levels in HCC cell lines. However, the mechanism underlying T{sub 3}-mediated regulation of DKK4 remains unknown. In the present study, the 5′ promoter region of DKK4 was serially deleted, and the reporter assay performed to localize the T{sub 3} response element (TRE). Consequently, we identified an atypical direct repeat TRE between nucleotides −1645 and −1629 conferring T{sub 3} responsiveness to the DKK4 gene. This region was further validated using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Stable DKK4 overexpression in SK-Hep-1 cells suppressed cell invasion and metastatic potential, both in vivo andin vitro, via reduction of matrix metalloproteinase-2 (MMP-2) expression. Our findings collectively suggest that DKK4 upregulated by T{sub 3}/TR antagonizes the Wnt signal pathway to suppress tumor cell progression, thus providing new insights into the molecular mechanism underlying thyroid hormone activity in HCC.

  6. Effect of salinity level on TSH and thyroid hormones of grass carp, Ctenophayngodon idella

    OpenAIRE

    Peyghan, Rahim; Enayati, Ala; Sabzevarizadeh, Mostafa

    2013-01-01

    Thyroid hormones (T3, T4) have marked effect on body metabolism and in controlling osmoregulation activity in fish. The aim of this study was to determine the effect of water salinity changes on thyroid hormones level and thyroid-stimulating hormone (TSH) of grass carp. For this purpose 120 grass carp were divided randomly in to four groups (10 fish in each group and three replicates per treatment). Three groups were held in three different salinities at concentrations of 4, 8 and 12 g L-1. T...

  7. [Thyroid proteins in endemic goitre and their relationship to the intrathyroidal thyroid hormone concentration].

    Science.gov (United States)

    Platzer, S; Groebner, P; Hausen, A; Obendorf, L; Riccabona, G

    1980-02-01

    According to several reports we suspected that the pathogenesis of endemic goitre cannot be explained by iodine deficiency only, but that other--partially endogenous--goitrogenic factors must be present. We therefore studied 16 cases of "euthyroid" endemic goitre from the endemic goitre area of the province of Bolzano in Italy. After fractionation of tissue homogenates, T 4 and T 3 were measured by RIA and the I concentration was also termined. Thyroglobulin and its fractions were measured by ultracentrifuge procedures after assessment of the total protein concentration. Evaluation of the present results suggests that an insufficient synthesis of thyroglobulin in the examined goitres induces an inadequate adaptation of the organism to iodine deficiency, which, in turn, decreases the thyroid hormone concentration in thyroid tissue and enhances goitrogenesis. Considering the normal iodine content of the examined tissues, there obviously seems to be two intrathyroidal iodine pools, one of which supplies the body with thyroid hormones under pituitary stimulation even though its thyroglobulin pool is reduced, while a significant amount of the thyroidal iodine pool is bound in metabolically inert protein molecules and therefore increases the goitrogenic effect of iodine deficiency.

  8. Circulating thyroid hormone levels and adequacy of dialysis.

    Science.gov (United States)

    Savdie, E; Stewart, J H; Mahony, J F; Hayes, J M; Lazarus, L; Simons, L A

    1978-02-01

    In vitro thyroid function tests were performed in three groups of patients with chronic renal failure who were receiving, on average, 15, 18 and 27 hours of maintenance hemodialysis per week. Total thyroxine levels were low and total triiodothyronine levels low to normal in those receiving the least dialysis (15 hours), and were significantly higher in those receiving longer dialysis. Free thyroxine levels, as measured by the effective thyroxine ratio, were normal and similar in all three groups, as were serum thyrotrophin levels. All patients were clinically euthyroid. As total hormone levels showed a significant inverse relationship to both urea and creatinine, this study suggests that there is a dialyzable metabolite retained in uremia which competes with thyroid hormones for protein-binding sites.

  9. correlation between cytology and thyroid function test

    African Journals Online (AJOL)

    Damary

    2006-10-01

    Oct 1, 2006 ... the hormones tri-iodothyronine T3 and thyroxine T4, which are in turn regulated by thyroid stimulating hormone (TSH), produced by the anterior pituitary gland. Diseases of the thyroid gland usually result in thyroid enlargement (goiter) which can be due to infections, cystic changes, autoimmune diseases, ...

  10. Thyroid hormone regulates muscle function during cold acclimation in zebrafish (Danio rerio).

    Science.gov (United States)

    Little, Alexander G; Seebacher, Frank

    2013-09-15

    Thyroid hormone (TH) is a universal regulator of growth, development and metabolism during cold exposure in mammals. In zebrafish (Danio rerio), TH regulates locomotor performance and metabolism during cold acclimation. The influence of TH on locomotor performance may be via its effect on metabolism or, as has been shown in mammals, by modulating muscle phenotypes. Our aim was to determine whether TH influences muscle phenotypes in zebrafish, and whether this could explain changes in swimming capacity in response to thermal acclimation. We used propylthiouracil and iopanoic acid to induce hypothyroidism in zebrafish over a 3-week acclimation period to either 18 or 28°C. To verify that physiological changes following hypothyroid treatment were in fact due to the action of TH, we supplemented hypothyroid fish with 3,5-diiodothryronine (T2) or 3,5,3'-triiodothyronine (T3). Cold-acclimated fish had significantly greater sustained swimming performance (Ucrit) but not burst speed. Greater Ucrit was accompanied by increased tail beat frequency, but there was no change in tail beat amplitude. Hypothyroidism significantly decreased Ucrit and burst performance, as well as tail beat frequency and SERCA activity in cold-acclimated fish. However, myofibrillar ATPase activity increased in cold-acclimated hypothyroid fish. Hypothyroid treatment also decreased mRNA concentrations of myosin heavy chain fast isoforms and SERCA 1 isoform in cold-acclimated fish. SERCA 1 mRNA increased in warm-acclimated hypothyroid fish, and SERCA 3 mRNA decreased in both cold- and warm-acclimated hypothyroid fish. Supplementation with either T2 or T3 restored Ucrit, burst speed, tail beat frequency, SERCA activity and myosin heavy chain and SERCA 1 and 3 mRNA levels of hypothyroid fish back to control levels. We show that in addition to regulating development and metabolism in vertebrates, TH also regulates muscle physiology in ways that affect locomotor performance in fish. We suggest that the

  11. Thyroid hormones and cardiac arrhythmias

    Czech Academy of Sciences Publication Activity Database

    Tribulová, N.; Knezl, V.; Shainberg, A.; Seki, S.; Soukup, Tomáš

    2010-01-01

    Roč. 52, 3-4 (2010), s. 102-112 ISSN 1537-1891 R&D Projects: GA ČR(CZ) GA304/08/0256 Grant - others:VEGA(SK) 2/0049/09; APVV(SK) 51-059505; APVV(SK) 51-017905 Institutional research plan: CEZ:AV0Z50110509 Keywords : thyroid hormone * arrhythmias * ion channels * connexin-43 Subject RIV: FA - Cardiovascular Disease s incl. Cardiotharic Surgery Impact factor: 2.174, year: 2010

  12. Hypothyroidism in Pancreatic Cancer: Role of Exogenous Thyroid Hormone in Tumor Invasion—Preliminary Observations

    Directory of Open Access Journals (Sweden)

    Konrad Sarosiek

    2016-01-01

    Full Text Available According to the epidemiological studies, about 4.4% of American general elderly population has a pronounced hypothyroidism and relies on thyroid hormone supplements daily. The prevalence of hypothyroidism in our patients with pancreatic cancer was much higher, 14.1%. A retrospective analysis was performed on patients who underwent pancreaticoduodenectomy (Whipple procedure or distal pancreatectomy and splenectomy (DPS at Thomas Jefferson University Hospital, Philadelphia, from 2005 to 2012. The diagnosis of hypothyroidism was correlated with clinicopathologic parameters including tumor stage, grade, and survival. To further understand how thyroid hormone affects pancreatic cancer behavior, functional studies including wound-induced cell migration, proliferation, and invasion were performed on pancreatic cancer cell lines, MiaPaCa-2 and AsPC-1. We found that hypothyroid patients taking exogenous thyroid hormone were more than three times likely to have perineural invasion, and about twice as likely to have higher T stage, nodal spread, and overall poorer prognostic stage (P<0.05. Pancreatic cancer cell line studies demonstrated that exogenous thyroid hormone treatment increased cell proliferation, migration, and invasion (P<0.05. We conclude that exogenous thyroid hormone may contribute to the progression of pancreatic cancer.

  13. Gene specific actions of thyroid hormone receptor subtypes.

    Directory of Open Access Journals (Sweden)

    Jean Z Lin

    Full Text Available There are two homologous thyroid hormone (TH receptors (TRs α and β, which are members of the nuclear hormone receptor (NR family. While TRs regulate different processes in vivo and other highly related NRs regulate distinct gene sets, initial studies of TR action revealed near complete overlaps in their actions at the level of individual genes. Here, we assessed the extent that TRα and TRβ differ in target gene regulation by comparing effects of equal levels of stably expressed exogenous TRs +/- T(3 in two cell backgrounds (HepG2 and HeLa. We find that hundreds of genes respond to T(3 or to unliganded TRs in both cell types, but were not able to detect verifiable examples of completely TR subtype-specific gene regulation. TR actions are, however, far from identical and we detect TR subtype-specific effects on global T(3 response kinetics in HepG2 cells and many examples of TR subtype specificity at the level of individual genes, including effects on magnitude of response to TR +/- T(3, TR regulation patterns and T(3 dose response. Cycloheximide (CHX treatment confirms that at least some differential effects involve verifiable direct TR target genes. TR subtype/gene-specific effects emerge in the context of widespread variation in target gene response and we suggest that gene-selective effects on mechanism of TR action highlight differences in TR subtype function that emerge in the environment of specific genes. We propose that differential TR actions could influence physiologic and pharmacologic responses to THs and selective TR modulators (STRMs.

  14. Thyroid Stimulating Hormone and Bone Mineral Density

    DEFF Research Database (Denmark)

    van Vliet, Nicolien A; Noordam, Raymond; van Klinken, Jan B

    2018-01-01

    With population aging, prevalence of low bone mineral density (BMD) and associated fracture risk are increased. To determine whether low circulating thyroid stimulating hormone (TSH) levels within the normal range are causally related to BMD, we conducted a two-sample Mendelian randomization (MR...

  15. The evaluation of free thyroid hormones (FT4 and FT3) in the routine diagnosis of thyroid function

    International Nuclear Information System (INIS)

    Passath, A.; Leb, G.; Goebel, R.

    1985-01-01

    The validity of the free thyroid hormone parameters (FT 4 and FT 3 ) was verified in a random sample of 154 ambulatory patients with thyroid conditions. The ''euthyroid range'' of FT 4 was between 15.67 and 30.66 pmol/l; median 21.98 pmol/l. The distribution of the FT 4 readings peaked on the left and sloped to the right (log normal). In our laboratory, the ''euthyroid reference range'' of FT 4 is between 10-28 pmol/l. The ''euthyroid range'' of FT 3 extended from 4.6 to 9.7 pmol/l; median 6.63 pmol/l. The distribution of the readings was likewise log normal. The values of FT 4 and FT 3 are not significantly influenced by TBG concentration anomalies in otherwise healthy thyroid patients. For purposes of discrimination between euthyroidism and hyperthyroidism, FT 3 (95%) and FT 4 (90%) are better suited than the corresponding quotients for the free hormone fraction or the total hormone concentrations. On the other hand, the free hormone parameters are less suitable for the diagnosis of hypothyroidism. These results were deduced theoretically from mathematical function analyses between the TBG-independent free hormone parameters and the TBG-dependent hormone concentrations. (orig.) [de

  16. Persistence of a circadian rhythmicity for thyroid hormones in plasma and thyroid of hibernating male Rana ridibunda.

    Science.gov (United States)

    Kühn, E R; Delmotte, N M; Darras, V M

    1983-06-01

    The presence and circadian rhythmicity of thyroid hormones was studied in plasma and the thyroid gland of male Rana ridibunda before and during hibernation. Hibernating January frogs do have a lower T3 and T4 content of their thyroid gland whereas plasma levels of T3 are maintained and of T4 increased compared to fed September or October frogs. It seems likely that the increased photoperiod in January will be responsible for this increased T4 secretion, since controlled laboratory experiments performed in December did not reveal any influence of low temperature on circulating T3 or T4 levels. Also feeding does not influence circulating levels and thyroid content of thyroid hormones in frogs kept at room temperature during the month of January. A circadian rhythmicity of T3 and T4 in the thyroid gland is present in fed October frogs and in non fed December frogs acclimated at 5 degrees C for 12 days with an acrophase for T3 at approximately 1500 h and for T4 at around 1900 h, whereas in plasma only T3 does have circadian variations (acrophase about midnight) but not T4. When December frogs are acclimated to room temperature for 12 days, frogs are active again, but do not eat and have a lower body weight than frogs hibernating at 5 degrees C. Their T3 content of the thyroid gland has disappeared, but T4 thyroid content and plasma levels of T3 and T4 are maintained. As in hibernating frogs, no circadian variations in T4 plasma concentrations are present whereas the circadian thyroid T4 rhythm disappears. At the same time a dampening in rhythmicity for plasma T3 as judged by the significantly lower amplitude occurs. It is concluded that the persistence of circulating levels of thyroid hormones and of a circadian cyclicity for T3 in plasma in non feeding hibernating frogs may reflect the special metabolic state e.g. availability of food reserves in these animals.

  17. Thyroid hormones and changes in body weight and metabolic parameters in response to weight loss diets: the POUNDS LOST trial.

    Science.gov (United States)

    Liu, G; Liang, L; Bray, G A; Qi, L; Hu, F B; Rood, J; Sacks, F M; Sun, Q

    2017-06-01

    The role of thyroid hormones in diet-induced weight loss and subsequent weight regain is largely unknown. To examine the associations between thyroid hormones and changes in body weight and resting metabolic rate (RMR) in a diet-induced weight loss setting. Data analysis was conducted among 569 overweight and obese participants aged 30-70 years with normal thyroid function participating in the 2-year Prevention of Obesity Using Novel Dietary Strategies (POUNDS) LOST randomized clinical trial. Changes in body weight and RMR were assessed during the 2-year intervention. Thyroid hormones (free triiodothyronine (T3), free thyroxine (T4), total T3, total T4 and thyroid-stimulating hormone (TSH)), anthropometric measurements and biochemical parameters were assessed at baseline, 6 months and 24 months. Participants lost an average of 6.6 kg of body weight during the first 6 months and subsequently regained an average of 2.7 kg of body weight over the remaining period from 6 to 24 months. Baseline free T3 and total T3 were positively associated, whereas free T4 was inversely associated, with baseline body weight, body mass index and RMR. Total T4 and TSH were not associated with these parameters. Higher baseline free T3 and free T4 levels were significantly associated with a greater weight loss during the first 6 months (Ppressure, glucose, insulin, triglycerides and leptin at 6 months and 24 months (all P<0.05). In this diet-induced weight loss setting, higher baseline free T3 and free T4 predicted more weight loss, but not weight regain among overweight and obese adults with normal thyroid function. These findings reveal a novel role of thyroid hormones in body weight regulation and may help identify individuals more responsive to weight loss diets.

  18. Bone loss in long-term suppressive therapy with thyroid hormone

    International Nuclear Information System (INIS)

    Firooznia, H.; Blum, M.; Golimbu, C.; Rafii, M.

    1987-01-01

    The trabecular bone density of the spine was measured with CT in 31 women, aged 39-79 years, who had received an average of 13.5 years of thyroid suppressive therapy. The spinal trabecular bone density values in 24 (77%), 18 (58%), and 13 subjects (42%) were respectively below the mean for healthy age-matched controls, the fifth percentile for healthy premenopausal women, and the fifth percentile for age-matched controls. Cortical and trabecular bone loss occurs in hyperthyroidism. Although the intent is not to cause hyperthyroidism in subjects on suppressive therapy, supraphysical doses of thyroid hormone are usually necessary for suppression of thyroid-stimulating hormone. In this study, bone loss was noted in these subjects. Because most of these patients are middle-aged or postmenopausal women, who are at risk for osteoporosis, it is important to be aware of the risk of additional bone loss induced by thyroid suppressive therapy in them

  19. The interaction between growth hormone and the thyroid axis in hypopituitary patients.

    LENUS (Irish Health Repository)

    Behan, Lucy Ann

    2011-03-01

    Alterations in the hypothalamo-pituitary-thyroid axis have been reported following growth hormone (GH) administration in both adults and children with and without growth hormone deficiency. Reductions in serum free thyroxine (T4), increased tri-iodothyronine (T3) with or without a reduction in serum thyroid-stimulating hormone secretion have been reported following GH replacement, but there are wide inconsistencies in the literature about these perturbations. The clinical significance of these changes in thyroid function remains uncertain. Some authors report the changes are transient and revert to normal after a few months or longer. However, in adult hypopituitary patients, GH replacement has been reported to unmask central hypothyroidism biochemically in 36-47% of apparently euthyroid patients, necessitating thyroxine replacement and resulting in an attenuation of the benefit of GH replacement on quality of life in those who became biochemically hypothyroid after GH replacement. The group at highest risk are those with organic pituitary disease or multiple pituitary hormone deficiencies. It is therefore prudent to monitor thyroid function in hypopituitary patients starting GH therapy to identify those who will develop clinical and biochemical features of central hypothyroidism, thus facilitating optimal and timely replacement.

  20. The interaction between growth hormone and the thyroid axis in hypopituitary patients.

    LENUS (Irish Health Repository)

    Behan, Lucy Ann

    2012-02-01

    Alterations in the hypothalamo-pituitary-thyroid axis have been reported following growth hormone (GH) administration in both adults and children with and without growth hormone deficiency. Reductions in serum free thyroxine (T4), increased tri-iodothyronine (T3) with or without a reduction in serum thyroid-stimulating hormone secretion have been reported following GH replacement, but there are wide inconsistencies in the literature about these perturbations. The clinical significance of these changes in thyroid function remains uncertain. Some authors report the changes are transient and revert to normal after a few months or longer. However, in adult hypopituitary patients, GH replacement has been reported to unmask central hypothyroidism biochemically in 36-47% of apparently euthyroid patients, necessitating thyroxine replacement and resulting in an attenuation of the benefit of GH replacement on quality of life in those who became biochemically hypothyroid after GH replacement. The group at highest risk are those with organic pituitary disease or multiple pituitary hormone deficiencies. It is therefore prudent to monitor thyroid function in hypopituitary patients starting GH therapy to identify those who will develop clinical and biochemical features of central hypothyroidism, thus facilitating optimal and timely replacement.

  1. [Correlations between PBDEs and thyroid hormone concentrations in adults from production source area].

    Science.gov (United States)

    Li, Ming-Yuan; Jin, Jun; Yang, Cong-Qiao; Wang, Ying; Ding, Wen-Wei; Yang, Xian-Feng; Liu, An-Ming

    2011-11-01

    Polybrominated diphenyl ethers (PBDEs) concentrations in 36 resident serum samples from PBDEs production source area were analyzed by gas chromatography/negative chemical ionization/mass spectrometry(GC-NCI-MS) method, and the concentrations of thyroid hormones were determined as well. The sigma5PBDEs (BDE-28, -47, -153, -183, -209) concentrations(lipid weight) in serum ranged from 130.3 to 4 478.4 ng x g(-1), with an average value of 529.9 ng x g(-1). BDE-209 was a dominant PBDE congener, on average accounting for 69.8% of the total PBDEs concentrations. Spearman rank correlation coefficient was calculated between PBDEs and thyroid hormone, it showed that there were high significant negative correlation between BDE-28, -47, -153, -183 and thyroid-stimulating hormone (TSH), and significant negative correlation was also found between BDE-183 and free thyroxine (fT4). Additionally, there were significant positive correlation between BDE-28, -47 and triiodothyronine (T3), as well as between BDE-28, -153, -183 and free triiodothyronine(fT3). In summary, the concentrations of PBDEs in serum in this study were at a high level, and BDE-209 was the predominant congener. The exposure to the PBDEs may affect thyroid hormone levels, and the further research should focus on the relationship between PBDEs and thyroid hormone concentrations.

  2. Characterization of thyroid hormone effects on Na-K pump and membrane potential of cultured rat skeletal myotubes

    International Nuclear Information System (INIS)

    Brodie, C.; Sampson, S.R.

    1988-01-01

    The purpose of this study was to characterize the effects of thyroid hormone on the Na-K pump and resting membrane potential (EM) of rat skeletal myotubes in culture. Myotubes were obtained from fetal (19-21 day) or neonatal rats (1-2 day) by serial trypsinization and maintained in culture for up to 10 days. Cells were treated with T4 or T3 on day 6 or 7, and measurements were made of EM, [ 3 H]ouabain binding, and ouabain-sensitive 86 Rb uptake at various times thereafter. Hormone treatment increased the values of all three variables within 24 h, plateau levels being attained by 48-72 h. Cycloheximide and actinomycin D totally blocked the effects of thyroid hormone when added together to the cells, thus suggesting that protein synthesis is necessary for the effects of these hormones. Scatchard analysis showed that the new receptors have lower ouabain affinity than those in control. Blockade of spontaneously occurring action potentials with tetrodotoxin, which blocks voltage-dependent Na channels, or Na/H antiporter with amiloride, abolished the hormone effects seen after 24 h and significantly reduced those obtained after 48 h of hormone treatment. The results demonstrate that thyroid hormone-induced increased amount and activity of the electrogenic Na-K pump in cultured myotubes occurs, at least in part, in response to an initial effect to increase Na influx. Moreover, the findings are consistent with the concept that the Na-K pump plays an important role in regulation of EM in this preparation

  3. Sex Differences in Brain Thyroid Hormone Levels during Early Post-Hatching Development in Zebra Finch (Taeniopygia guttata.

    Directory of Open Access Journals (Sweden)

    Shinji Yamaguchi

    Full Text Available Thyroid hormones are closely linked to the hatching process in precocial birds. Previously, we showed that thyroid hormones in brain had a strong impact on filial imprinting, an early learning behavior in newly hatched chicks; brain 3,5,3'-triiodothyronine (T3 peaks around hatching and imprinting training induces additional T3 release, thus, extending the sensitive period for imprinting and enabling subsequent other learning. On the other hand, blood thyroid hormone levels have been reported to increase gradually after hatching in altricial species, but it remains unknown how the brain thyroid hormone levels change during post-hatching development of altricial birds. Here, we determined the changes in serum and brain thyroid hormone levels of a passerine songbird species, the zebra finch using radioimmunoassay. In the serum, we found a gradual increase in thyroid hormone levels during post-hatching development, as well as differences between male and female finches. In the brain, there was clear surge in the hormone levels during development in males and females coinciding with the time of fledging, but the onset of the surge of thyroxine (T4 in males preceded that of females, whereas the onset of the surge of T3 in males succeeded that of females. These findings provide a basis for understanding the functions of thyroid hormones during early development and learning in altricial birds.

  4. Sex Differences in Brain Thyroid Hormone Levels during Early Post-Hatching Development in Zebra Finch (Taeniopygia guttata).

    Science.gov (United States)

    Yamaguchi, Shinji; Hayase, Shin; Aoki, Naoya; Takehara, Akihiko; Ishigohoka, Jun; Matsushima, Toshiya; Wada, Kazuhiro; Homma, Koichi J

    2017-01-01

    Thyroid hormones are closely linked to the hatching process in precocial birds. Previously, we showed that thyroid hormones in brain had a strong impact on filial imprinting, an early learning behavior in newly hatched chicks; brain 3,5,3'-triiodothyronine (T3) peaks around hatching and imprinting training induces additional T3 release, thus, extending the sensitive period for imprinting and enabling subsequent other learning. On the other hand, blood thyroid hormone levels have been reported to increase gradually after hatching in altricial species, but it remains unknown how the brain thyroid hormone levels change during post-hatching development of altricial birds. Here, we determined the changes in serum and brain thyroid hormone levels of a passerine songbird species, the zebra finch using radioimmunoassay. In the serum, we found a gradual increase in thyroid hormone levels during post-hatching development, as well as differences between male and female finches. In the brain, there was clear surge in the hormone levels during development in males and females coinciding with the time of fledging, but the onset of the surge of thyroxine (T4) in males preceded that of females, whereas the onset of the surge of T3 in males succeeded that of females. These findings provide a basis for understanding the functions of thyroid hormones during early development and learning in altricial birds.

  5. Hyperactivity and Learning Deficits in Transgenic Mice Bearing a Human Mutant Thyroid Hormone β1 Receptor Gene

    OpenAIRE

    McDonald, Michael P.; Wong, Rosemary; Goldstein, Gregory; Weintraub, Bruce; Cheng, Sheue-yann; Crawley, Jacqueline N.

    1998-01-01

    Resistance to thyroid hormone (RTH) is a human syndrome mapped to the thyroid receptor β (TRβ) gene on chromosome 3, representing a mutation of the ligandbinding domain of the TRβ gene. The syndrome is characterized by reduced tissue responsiveness to thyroid hormone and elevated serum levels of thyroid hormones. A common behavioral phenotype associated with RTH is attention deficit hyperactivity disorder (ADHD). To test the hypothesis that RTH produces attention deficits and/or hyperactivity...

  6. Differential regulation of monocarboxylate transporter 8 expression in thyroid cancer and hyperthyroidism.

    Science.gov (United States)

    Badziong, Julia; Ting, Saskia; Synoracki, Sarah; Tiedje, Vera; Brix, Klaudia; Brabant, Georg; Moeller, Lars Christian; Schmid, Kurt Werner; Fuhrer, Dagmar; Zwanziger, Denise

    2017-09-01

    Thyroid hormone (TH) transporters are expressed in thyrocytes and most play a role in TH release. We asked whether expression of the monocarboxylate transporter 8 (MCT8) and the L-type amino acid transporters LAT2 and LAT4 is changed with thyrocyte dedifferentiation and in hyperfunctioning thyroid tissues. Protein expression and localization of transporters was determined by immunohistochemistry in human thyroid specimen including normal thyroid tissue (NT, n  = 19), follicular adenoma (FA, n  = 44), follicular thyroid carcinoma (FTC, n  = 45), papillary thyroid carcinoma (PTC, n  = 40), anaplastic thyroid carcinoma (ATC, n  = 40) and Graves' disease (GD, n  = 50) by calculating the 'hybrid' (H) score. Regulation of transporter expression was investigated in the rat follicular thyroid cell line PCCL3 under basal and thyroid stimulating hormone (TSH) conditions. MCT8 and LAT4 were localized at the plasma membrane, while LAT2 transporter showed cytoplasmic localization. MCT8 expression was downregulated in benign and malignant thyroid tumours as compared to NT. In contrast, significant upregulation of MCT8, LAT2 and LAT4 was found in GD. Furthermore, a stronger expression of MCT8 was demonstrated in PCCL3 cells after TSH stimulation. Downregulation of MCT8 in thyroid cancers qualifies MCT8 as a marker of thyroid differentiation. The more variable expression of LATs in distinct thyroid malignancies may be linked with other transporter properties relevant to altered metabolism in cancer cells, i.e. amino acid transport. Consistent upregulation of MCT8 in GD is in line with increased TH release in hyperthyroidism, an assumption supported by our in vitro results showing TSH-dependent upregulation of MCT8. © 2017 European Society of Endocrinology.

  7. Thyroid Disorders and Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Mohamed Mohamedali

    2014-01-01

    Full Text Available Thyroid hormones play a very important role regulating metabolism, development, protein synthesis, and influencing other hormone functions. The two main hormones produced by the thyroid are triiodothyronine (T3 and thyroxine (T4. These hormones can also have significant impact on kidney disease so it is important to consider the physiological association of thyroid dysfunction in relation to chronic kidney disease (CKD. CKD has been known to affect the pituitary-thyroid axis and the peripheral metabolism of thyroid hormones. Low T3 levels are the most common laboratory finding followed by subclinical hypothyroidism in CKD patients. Hyperthyroidism is usually not associated with CKD but has been known to accelerate it. One of the most important links between thyroid disorders and CKD is uremia. Patients who are appropriately treated for thyroid disease have a less chance of developing renal dysfunction. Clinicians need to be very careful in treating patients with low T3 levels who also have an elevation in TSH, as this can lead to a negative nitrogen balance. Thus, clinicians should be well educated on the role of thyroid hormones in relation to CKD so that proper treatment can be delivered to the patient.

  8. Effect of neonatal hypothyroidism on prepubertal mouse testis in relation to thyroid hormone receptor alpha 1 (THRα1).

    Science.gov (United States)

    Sarkar, Debarshi; Singh, Shio Kumar

    2017-09-15

    Thyroid hormones (THs) are important for growth and development of many tissues, and altered thyroid status affects various organs and systems. Testis also is considered as a thyroid hormone responsive organ. Though THs play an important role in regulation of testicular steroidogenesis and spermatogenesis, the exact mechanism of this regulation remains poorly understood. The present study, therefore, is designed to examine the effect of neonatal hypothyroidism on prepubertal Parkes (P) strain mice testis in relation to thyroid hormone receptor alpha 1 (THRα1). Hypothyroidism was induced by administration of 6-propyl-2-thiouracil (PTU) in mother's drinking water from birth to day 28; on postnatal day (PND) 21 only pups, and on PND 28, both pups and lactating dams were euthanized. Serum T 3 and T 4 were markedly reduced in pups at PND 28 and in lactating mothers, while serum and intra-testicular testosterone levels were considerably decreased in pups of both age groups. Further, serum and intra-testicular levels of estrogen were significantly increased in hypothyroid mice at PND 28 with concomitant increase in CYP19 expression. Histologically, marked changes were noticed in testes of PTU-treated mice; immunohistochemical and western blot analyses of testes in treated mice also revealed marked decrease in the expression of THRα1 at both age groups. Semiquantitative RT-PCR and western blot analyses also showed reductions in both testicular mRNA and protein levels of SF-1, StAR, CYP11A1 and 3β-HSD in these mice. In conclusion, our results suggest that neonatal hypothyroidism alters localization and expression of THRα1 and impairs testicular steroidogenesis by down-regulating the expression SF-1, thereby affecting spermatogenesis in prepubertal mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Thyroid-hormone concentrations after radioiodine therapy for hyperthyroidism

    International Nuclear Information System (INIS)

    Tamagna, E.I.; Levine, G.A.; Hershman, J.M.

    1979-01-01

    Fourteen hyperthyroid patients (11 men, three women), ages 28 to 66, were followed with serial measurements of serum thyroid hormone levels for 1 mo after therapy with I-131. Twelve patients had diffuse toxic goiters (25 to 70 g in size); two patients had multinodular glands (40 to 100 g). The patients were taking no antithyroid medications; ten patients were treated with propranolol. All patients received the equivalent of 5000 rad, except the two with multinodular glands, who received larger doses. There was no consistent pattern of serum T 4 and T 3 levels after the I-131 therapy. For the entire group, there was no significant increase of the mean serum hormone concentration. One group (three patients) had a mean T 4 increase of 28% and a T 3 increase of 91% above baseline at Days 10--11. Seven patients had minimal increases of hormone levels at Days 2--3, and a third group (four paients) had no increase of thyroid hormones after I-131 therapy. The patients with no rise in hormone concentrations had smaller goiters than the other groups. There was no correlation of the dose of radioactive iodine, or of the initial hormone concentration, with the rises or declines of T 4 and T 3 levels after I-131 therapy. Radioiodine therapy caused no significant increase of serum T 4 and T 3 concentrations in the majority of patients

  10. Myopathy in hyperthyroidism as a consequence of rapid reduction of thyroid hormone

    OpenAIRE

    Li, Qianrui; Liu, Yuping; Zhang, Qianying; Tian, Haoming; Li, Jianwei; Li, Sheyu

    2017-01-01

    Abstract Rationale: Myalgia and elevated creatine kinase (CK) are occasionally observed during the treatment of hyperthyroid patients. Relative hypothyroidism resulted from rapid thyroid hormone reduction had been promoted as a plausible cause of these myopathic changes, however rarely reported. Patient concerns: We hereby presented a 20-year-old female with Grave's disease, who developed myopathy and elevated CK during rapid correction of thyroid hormone. Diagnoses: Relative hypothyroidism-i...

  11. Hypertrophic response of the Association of Thyroid Hormone and Exercise in the Heart of Rats

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fernanda Rodrigues de, E-mail: nandaeduca@yahoo.com.br; Resende, Elmiro Santos; Lopes, Leandro; Gonçalves, Alexandre; Chagas, Rafaella; Fidale, Thiago; Rodrigues, Poliana [UFU - Universidade Federal de Uberlândia, Uberlândia, MG (Brazil)

    2014-02-15

    Cardiac hypertrophy is a component of cardiac remodeling occurring in response to an increase of the activity or functional overload of the heart. Assess hypertrophic response of the association of thyroid hormone and exercise in the rat heart. We used 37 Wistar rats, male, adults were randomly divided into four groups: control, hormone (TH), exercise (E), thyroid hormone and exercise (H + E); the group received daily hormone levothyroxine sodium by gavage at a dose of 20 μg thyroid hormone/100g body weight, the exercise group took swimming five times a week, with additional weight corresponding to 20% of body weight for six weeks; in group H + E were applied simultaneously TH treatment groups and E. The statistics used was analysis of variance, where appropriate, by Tukey test and Pearson correlation test. The T4 was greater in groups TH and H + E. The total weight of the heart was greater in patients who received thyroid hormone and left ventricular weight was greater in the TH group. The transverse diameter of cardiomyocytes increased in groups TH, E and H + E. The percentage of collagen was greater in groups E and H + E Correlation analysis between variables showed distinct responses. The association of thyroid hormone with high-intensity exercise produced cardiac hypertrophy, and generated a standard hypertrophy not directly correlated to the degree of fibrosis.

  12. Guidelines for the treatment of hypothyroidism: prepared by the american thyroid association task force on thyroid hormone replacement.

    Science.gov (United States)

    Jonklaas, Jacqueline; Bianco, Antonio C; Bauer, Andrew J; Burman, Kenneth D; Cappola, Anne R; Celi, Francesco S; Cooper, David S; Kim, Brian W; Peeters, Robin P; Rosenthal, M Sara; Sawka, Anna M

    2014-12-01

    A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy. The purpose of this task force was to review the goals of levothyroxine therapy, the optimal prescription of conventional levothyroxine therapy, the sources of dissatisfaction with levothyroxine therapy, the evidence on treatment alternatives, and the relevant knowledge gaps. We wished to determine whether there are sufficient new data generated by well-designed studies to provide reason to pursue such therapies and change the current standard of care. This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment. Task force members identified 24 questions relevant to the treatment of hypothyroidism. The clinical literature relating to each question was then reviewed. Clinical reviews were supplemented, when relevant, with related mechanistic and bench research literature reviews, performed by our team of translational scientists. Ethics reviews were provided, when relevant, by a bioethicist. The responses to questions were formatted, when possible, in the form of a formal clinical recommendation statement. When responses were not suitable for a formal clinical recommendation, a summary response statement without a formal clinical recommendation was developed. For clinical recommendations, the supporting evidence was appraised, and the strength of each clinical recommendation was assessed, using the American College of Physicians system. The final document was organized so that each topic is introduced with a question, followed by a formal clinical recommendation. Stakeholder input was received at a national meeting, with some subsequent refinement of the clinical questions addressed in the document. Consensus was achieved for all recommendations by the task force. We reviewed the following therapeutic

  13. Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

    Directory of Open Access Journals (Sweden)

    Mayte Alvarez-Crespo

    2016-04-01

    Full Text Available Objective: Classically, metabolic effects of thyroid hormones (THs have been considered to be peripherally mediated, i.e. different tissues in the body respond directly to thyroid hormones with an increased metabolism. An alternative view is that the metabolic effects are centrally regulated. We have examined here the degree to which prolonged, centrally infused triiodothyronine (T3 could in itself induce total body metabolic effects and the degree to which brown adipose tissue (BAT thermogenesis was essential for such effects, by examining uncoupling protein 1 (UCP1 KO mice. Methods: Wildtype and UPC1 KO mice were centrally-treated with T3 by using minipumps. Metabolic measurements were analyzed by indirect calorimetry and expression analysis by RT-PCR or western blot. BAT morphology and histology were studied by immunohistochemistry. Results: We found that central T3-treatment led to reduced levels of hypothalamic AMP-activated protein kinase (AMPK and elevated body temperature (0.7 °C. UCP1 was essential for the T3-induced increased rate of energy expenditure, which was only observable at thermoneutrality and notably only during the active phase, for the increased body weight loss, for the increased hypothalamic levels of neuropeptide Y (NPY and agouti-related peptide (AgRP and for the increased food intake induced by central T3-treatment. Prolonged central T3-treatment also led to recruitment of BAT and britening/beiging (“browning” of inguinal white adipose tissue (iWAT. Conclusions: We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents. Keywords: AMPK, Brown adipose tissue, Hypothalamus, Thyroid hormones, UCP1

  14. Exogenous thyroid hormones regulate the activity of citrate synthase and cytochrome c oxidase in warm- but not cold-acclimated lake whitefish (Coregonus clupeaformis)

    Science.gov (United States)

    Zak, Megan A.; Regish, Amy M.; McCormick, Stephen; Manzon, Richard G.

    2017-01-01

    Thermal acclimation is known to elicit metabolic adjustments in ectotherms, but the cellular mechanisms and endocrine control of these shifts have not been fully elucidated. Here we examined the relationship between thermal acclimation, thyroid hormones and oxidative metabolism in juvenile lake whitefish. Impacts of thermal acclimation above (19 °C) or below (8 °C) the thermal optimum (13 °C) and exposure to exogenous thyroid hormone (60 µg T4/g body weight) were assessed by quantifying citrate synthase and cytochrome c oxidase activities in liver, red muscle, white muscle and heart. Warm acclimation decreased citrate synthase activity in liver and elevated both citrate synthase and cytochrome c oxidase activities in red muscle. In contrast, induction of hyperthyroidism in warm-acclimated fish stimulated a significant increase in liver citrate synthase and heart cytochrome c oxidase activities, and a decrease in the activity of both enzymes in red muscle. No change in citrate synthase or cytochrome c oxidase activities was observed following cold acclimation in either the presence or absence of exogenous thyroid hormones. Collectively, our results indicate that thyroid hormones influence the activity of oxidative enzymes more strongly in warm-acclimated than in cold-acclimated lake whitefish, and they may play a role in mediating metabolic adjustments observed during thermal acclimation.

  15. Exogenous thyroid hormones regulate the activity of citrate synthase and cytochrome c oxidase in warm- but not cold-acclimated lake whitefish (Coregonus clupeaformis).

    Science.gov (United States)

    Zak, Megan A; Regish, Amy M; McCormick, Stephen D; Manzon, Richard G

    2017-06-01

    Thermal acclimation is known to elicit metabolic adjustments in ectotherms, but the cellular mechanisms and endocrine control of these shifts have not been fully elucidated. Here we examined the relationship between thermal acclimation, thyroid hormones and oxidative metabolism in juvenile lake whitefish. Impacts of thermal acclimation above (19°C) or below (8°C) the thermal optimum (13°C) and exposure to exogenous thyroid hormone (60µg T 4 /g body weight) were assessed by quantifying citrate synthase and cytochrome c oxidase activities in liver, red muscle, white muscle and heart. Warm acclimation decreased citrate synthase activity in liver and elevated both citrate synthase and cytochrome c oxidase activities in red muscle. In contrast, induction of hyperthyroidism in warm-acclimated fish stimulated a significant increase in liver citrate synthase and heart cytochrome c oxidase activities, and a decrease in the activity of both enzymes in red muscle. No change in citrate synthase or cytochrome c oxidase activities was observed following cold acclimation in either the presence or absence of exogenous thyroid hormones. Collectively, our results indicate that thyroid hormones influence the activity of oxidative enzymes more strongly in warm-acclimated than in cold-acclimated lake whitefish, and they may play a role in mediating metabolic adjustments observed during thermal acclimation. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Human longevity is characterised by high thyroid stimulating hormone secretion without altered energy metabolism

    OpenAIRE

    Jansen, S. W.; Akintola, A. A.; Roelfsema, F.; van der Spoel, E.; Cobbaert, C. M.; Ballieux, B. E.; Egri, P.; Kvarta-Papp, Z.; Gereben, B.; Fekete, C.; Slagboom, P. E.; van der Grond, J.; Demeneix, B. A.; Pijl, H.; Westendorp, R. G. J.

    2015-01-01

    Few studies have included subjects with the propensity to reach old age in good health, with the aim to disentangle mechanisms contributing to staying healthier for longer. The hypothalamic-pituitary-thyroid (HPT) axis maintains circulating levels of thyroid stimulating hormone (TSH) and thyroid hormone (TH) in an inverse relationship. Greater longevity has been associated with higher TSH and lower TH levels, but mechanisms underlying TSH/TH differences and longevity remain unknown. The HPT a...

  17. Thyroid Disorders Overview

    Science.gov (United States)

    ... body breaks down food and either uses that energy immediately or stores it for the future. In other words, our thyroid hormones regulate our body's metabolism. Another gland, called the pituitary gland, actually controls how well the thyroid works. The pituitary gland ...

  18. Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

    Directory of Open Access Journals (Sweden)

    Debora Lucia Seguro Danilovic

    2011-01-01

    Full Text Available OBJECTIVE: To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C. INTRODUCTION: Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis. METHODS: We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy. RESULTS: Of the patients in our study, 54% had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH levels remained stable. A total of 19% of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16% had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11% remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns. DISCUSSION: Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis. CONCLUSION: Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels, which occur despite stable free T4 and TSH levels. A thyroid

  19. Thyroid Hormone Receptor β (TRβ) and Liver X Receptor (LXR) Regulate Carbohydrate-response Element-binding Protein (ChREBP) Expression in a Tissue-selective Manner*

    Science.gov (United States)

    Gauthier, Karine; Billon, Cyrielle; Bissler, Marie; Beylot, Michel; Lobaccaro, Jean-Marc; Vanacker, Jean-Marc; Samarut, Jacques

    2010-01-01

    Thyroid hormone (TR) and liver X (LXR) receptors are transcription factors involved in lipogenesis. Both receptors recognize the same consensus DNA-response element in vitro. It was previously shown that their signaling pathways interact in the control of cholesterol elimination in the liver. In the present study, carbohydrate-response element-binding protein (ChREBP), a major transcription factor controlling the activation of glucose-induced lipogenesis in liver, is characterized as a direct target of thyroid hormones (TH) in liver and white adipose tissue (WAT), the two main lipogenic tissues in mice. Using genetic and molecular approaches, ChREBP is shown to be specifically regulated by TRβ but not by TRα in vivo, even in WAT where both TR isoforms are expressed. However, this isotype specificity is not found in vitro. This TRβ specific regulation correlates with the loss of TH-induced lipogenesis in TRβ−/− mice. Fasting/refeeding experiments show that TRβ is not required for the activation of ChREBP expression particularly marked in WAT following refeeding. However, TH can stimulate ChREBP expression in WAT even under fasting conditions, suggesting completely independent pathways. Because ChREBP has been described as an LXR target, the interaction of LXR and TRβ in ChREBP regulation was assayed both in vitro and in vivo. Each receptor recognizes a different response element on the ChREBP promoter, located only 8 bp apart. There is a cross-talk between LXR and TRβ signaling on the ChREBP promoter in liver but not in WAT where LXR does not regulate ChREBP expression. The molecular basis for this cross-talk has been determined in in vitro systems. PMID:20615868

  20. BRAFV600E mutation contributes papillary thyroid carcinoma and Hashimoto thyroiditis with resistance to thyroid hormone: A case report and literature review.

    Science.gov (United States)

    Xing, Wanjia; Liu, Xiaohong; He, Qingqing; Zhang, Zongjing; Jiang, Zhaoshun

    2017-09-01

    Resistance to thyroid hormone (RTH) is a rare autosomal hereditary disorder characterized by increased serum thyroid hormone (TH) levels with unsuppressed or increased thyrotropin concentration. It remains unknown whether the coexistence of RTH with papillary thyroid carcinoma (PTC) and Hashimoto thyroiditis (HT) is incidental or whether it possesses a genetic or pathophysiological association. In the present study, a case of RTH with PTC and HT in an 11-year-old Chinese patient was examined and the clinical presentation of RTH with PTC was discussed. In addition, the possible associations between RTH, PTC and HT were determined. HT was confirmed in the patient using an autoimmune assay and thyroid ultrasound. RTH was diagnosed on the basis of clinical manifestations, laboratory information and gene analysis, and PTC was diagnosed according to histological results. Results of BRAF V600E mutation analysis were positive. A literature review of 14 cases of RTH with PTC was included for comparison. The present case report indicates an association of RTH with PTC and HT coexistence in the patient. Close follow-up, histological evaluation and BRAF V600E mutation detection should be performed in each RTH case with HT, since a persistent increase in TSH may be a risk factor for the development of thyroid neoplasm.

  1. Comments to guidelines for the treatment of hypothyroidism prepared by the American thyroid association task force on thyroid hormone replacement

    Directory of Open Access Journals (Sweden)

    Valentin Viktorovich Fadeev

    2015-02-01

    Full Text Available The article is dedicated to the discussion about to guidelines for the treatment of hypothyroidism prepared by the American thyroid association task force on thyroid hormone replacement.

  2. The effect of growth hormone replacement on the thyroid axis in patients with hypopituitarism: in vivo and ex vivo studies.

    Science.gov (United States)

    Glynn, Nigel; Kenny, Helena; Quisenberry, Leah; Halsall, David J; Cook, Paul; Kyaw Tun, Tommy; McDermott, John H; Smith, Diarmuid; Thompson, Christopher J; O'Gorman, Donal J; Boelen, Anita; Lado-Abeal, Joaquin; Agha, Amar

    2017-05-01

    Alterations in the hypothalamic-pituitary-thyroid axis have been reported following growth hormone (GH) replacement. The aim was to examine the relationship between changes in serum concentration of thyroid hormones and deiodinase activity in subcutaneous adipose tissue, before and after GH replacement. A prospective, observational study of patients receiving GH replacement as part of routine clinical care. Twenty adult hypopituitary men. Serum TSH, thyroid hormones - free and total thyroxine (T4) and triiodothyronine (T3) and reverse T3, thyroglobulin and thyroid-binding globulin (TBG) levels were measured before and after GH substitution. Changes in serum hormone levels were compared to the activity of deiodinase isoenzymes (DIO1, DIO2 and DIO3) in subcutaneous adipose tissue. The mean daily dose of growth hormone (GH) was 0·34 ± 0·11 mg (range 0·15-0·5 mg). Following GH replacement, mean free T4 levels declined (-1·09 ± 1·99 pmol/l, P = 0·02). Reverse T3 levels also fell (-3·44 ± 1·42 ng/dl, P = 0·03) and free T3 levels increased significantly (+0·34 ± 0·15 pmol/l, P = 0·03). In subcutaneous fat, DIO2 enzyme activity declined; DIO1 and DIO3 activities remained unchanged following GH substitution. Serum TSH, thyroglobulin and TBG levels were unaltered by GH therapy. In vitro analysis of subcutaneous adipose tissue from hypopituitary human subjects demonstrates that GH replacement is associated with significant changes in deiodinase isoenzyme activity. However, the observed variation in enzyme activity does not explain the changes in the circulating concentration of thyroid hormones induced by GH replacement. It is possible that deiodinase isoenzymes are differentially regulated by GH in other tissues including liver and muscle. © 2016 John Wiley & Sons Ltd.

  3. Variability of Hormonal Stress Markers Collected from a Managed Dolphin Population

    Science.gov (United States)

    2013-09-30

    presence of thyroid stimulating hormone (TSH), which is a peptide hormone produced in the anterior pituitary gland . Thyroid stimulating hormone is 4...releasing hormone (TRH) challenges to characterize the activation of the hypothalamic- pituitary -adrenal (HPA) and hypothalamic- pituitary - thyroid (HPT...triiodothyronine, T3) are released from the thyroid gland and are responsible for regulating the metabolism of an animal and affect the activity of other stress

  4. Quantitative Adverse Outcome Pathway for Neurodevelopmental Effects of Thyroid Peroxidase-Induced Thyroid Hormone Synthesis Inhibition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Adequate levels of thyroid hormones (TH) are needed for proper brain development, deficiencies may lead to adverse neurological outcomes in humans and animal models....

  5. Early Phthalates Exposure in Pregnant Women Is Associated with Alteration of Thyroid Hormones.

    Directory of Open Access Journals (Sweden)

    Po-Chin Huang

    Full Text Available Previous studies revealed that phthalate exposure could alter thyroid hormones during the last trimester of pregnancy. However, thyroid hormones are crucial for fetal development during the first trimester. We aimed to clarify the effect of phthalate exposure on thyroid hormones during early pregnancy.We recruited 97 pregnant women who were offered an amniocentesis during the early trimester from an obstetrics clinic in southern Taiwan from 2013 to 2014. After signing an informed consent form, we collected amniotic fluid and urine samples from pregnant women to analyze 11 metabolites, including mono-ethyl phthalate (MEP, mono-(2-ethyl-5-carboxypentyl phthalate (MECPP, mono-(2-ethylhexyl phthalate (MEHP, mono-butyl phthalate (MnBP, of 9 phthalates using liquid chromatography/ tandem mass spectrometry. We collected blood samples from each subject to analyze serum thyroid hormones including thyroxine (T4, free T4, and thyroid-binding globulin (TBG.Three phthalate metabolites were discovered to be >80% in the urine samples of the pregnant women: MEP (88%, MnBP (81% and MECPP (86%. Median MnBP and MECPP levels in pregnant Taiwanese women were 21.5 and 17.6 μg/g-creatinine, respectively, that decreased after the 2011 Taiwan DEHP scandal. Results of principal component analysis suggested two major sources (DEHP and other phthalates of phthalates exposure in pregnant women. After adjusting for age, gestational age, TBG, urinary creatinine, and other phthalate metabolites, we found a significantly negative association between urinary MnBP levels and serum T4 (β = -5.41; p-value = 0.012; n = 97 in pregnant women using Bonferroni correction.We observed a potential change in the thyroid hormones of pregnant women during early pregnancy after DnBP exposure. Additional study is necessitated to clarify these associations.

  6. Analysis of thyroid hormone receptor βA mRNA expression in Xenopus laevis tadpoles as a means to detect agonism and antagonism of thyroid hormone action

    International Nuclear Information System (INIS)

    Opitz, Robert; Lutz, Ilka; Nguyen, Ngoc-Ha; Scanlan, Thomas S.; Kloas, Werner

    2006-01-01

    Amphibian metamorphosis represents a unique biological model to study thyroid hormone (TH) action in vivo. In this study, we examined the utility of thyroid hormone receptors α (TRα) and βA (TRβA) mRNA expression patterns in Xenopus laevis tadpoles as molecular markers indicating modulation of TH action. During spontaneous metamorphosis, only moderate changes were evident for TRα gene expression whereas a marked up-regulation of TRβA mRNA occurred in hind limbs (prometamorphosis), head (late prometamorphosis), and tail tissue (metamorphic climax). Treatment of premetamorphic tadpoles with 1 nM 3,5,3'-triiodothyronine (T3) caused a rapid induction of TRβA mRNA in head and tail tissue within 6 to 12 h which was maintained for at least 72 h after initiation of T3 treatment. Developmental stage had a strong influence on the responsiveness of tadpole tissues to induce TRβA mRNA during 24 h treatment with thyroxine (0, 1, 5, 10 nM T4) or T3 (0, 1, 5, 10 nM). Premetamorphic tadpoles were highly sensitive in their response to T4 and T3 treatments, whereas sensitivity to TH was decreased in early prometamorphic tadpoles and strongly diminished in late prometamorphic tadpoles. To examine the utility of TRβA gene expression analysis for detection of agonistic and antagonistic effects on T3 action, mRNA expression was assessed in premetamorphic tadpoles after 48 h of treatment with the synthetic agonist GC-1 (0, 10, 50, 250 nM), the synthetic antagonist NH-3 (0, 40, 200, 1000 nM), and binary combinations of NH-3 (0, 40, 200, 1000 nM) and T3 (1 nM). All tested concentrations of GC-1 as well as the highest concentration of NH-3 caused an up-regulation of TRβA expression. Co-treatment with NH-3 and T3 revealed strong antagonistic effects by NH-3 on T3-induced TRβA mRNA up-regulation. Results of this study suggest that TRβA mRNA expression analysis could serve as a sensitive molecular testing approach to study effects of environmental compounds on the thyroid system in

  7. Interrelación entre hormonas tiroideas y crecimiento: importancia clínica Interrelation between thyroid hormones and growth: clinical importance

    Directory of Open Access Journals (Sweden)

    Daysi A. Navarro Despaigne

    2005-12-01

    Full Text Available En la práctica clínica correspondiente a la endocrinología pediátrica, los trastornos del crecimiento son motivo frecuente de consulta y es la hipofunción tiroidea su causa más común. Por esta razón nos propusimos revisar aspectos teóricos relacionados con la función tiroidea, que pudieran explicar el mecanismo mediante el cual las hormonas tiroideas intervienen en el desarrollo del cartílago de crecimiento y del sistema nervioso central. Se revisa brevemente el mecanismo de regulación de las hormonas tiroideas y del efecto de los factores de crecimiento, tanto en la vida intrauterina como en la etapa posnatal. Se expone una hipótesis para explicar cómo ocurre la interrelación entre hormonas tiroideas (factores de crecimiento. Al final se hace referencia al impacto clínico del déficit de hormonas tiroideas durante la infancia.In the clinical practice of pediatric endocrinology, growth disorders is the most frequent reason to go to the doctor´s , being thyroid hypofunction the most common cause of this problem. For this reason, we intended to review theoretical aspects of thyroid function that could explain the mechanism by which thyroid hormones intervene in the development of growth cartilage and of the central nervous system. The regulating thyroid hormone mechanism along with the effect of growth factors on both intrauterine and postnatal life stages was briefly examined. A hypothesis of how the interrelation between thyroid hormones (growth factors occurs was presented. Finally, reference was made on the clinical impact of thyroid hormone deficit in childhood.

  8. Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement

    Science.gov (United States)

    Bianco, Antonio C.; Bauer, Andrew J.; Burman, Kenneth D.; Cappola, Anne R.; Celi, Francesco S.; Cooper, David S.; Kim, Brian W.; Peeters, Robin P.; Rosenthal, M. Sara; Sawka, Anna M.

    2014-01-01

    Background: A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy. The purpose of this task force was to review the goals of levothyroxine therapy, the optimal prescription of conventional levothyroxine therapy, the sources of dissatisfaction with levothyroxine therapy, the evidence on treatment alternatives, and the relevant knowledge gaps. We wished to determine whether there are sufficient new data generated by well-designed studies to provide reason to pursue such therapies and change the current standard of care. This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment. Methods: Task force members identified 24 questions relevant to the treatment of hypothyroidism. The clinical literature relating to each question was then reviewed. Clinical reviews were supplemented, when relevant, with related mechanistic and bench research literature reviews, performed by our team of translational scientists. Ethics reviews were provided, when relevant, by a bioethicist. The responses to questions were formatted, when possible, in the form of a formal clinical recommendation statement. When responses were not suitable for a formal clinical recommendation, a summary response statement without a formal clinical recommendation was developed. For clinical recommendations, the supporting evidence was appraised, and the strength of each clinical recommendation was assessed, using the American College of Physicians system. The final document was organized so that each topic is introduced with a question, followed by a formal clinical recommendation. Stakeholder input was received at a national meeting, with some subsequent refinement of the clinical questions addressed in the document. Consensus was achieved for all recommendations by the task force. Results: We reviewed the

  9. The Role of the Multiple Hormonal Dysregulation in the Onset of “Anemia of Aging”: Focus on Testosterone, IGF-1, and Thyroid Hormones

    Directory of Open Access Journals (Sweden)

    Marcello Maggio

    2015-01-01

    Full Text Available Anemia is a multifactorial condition whose prevalence increases in both sexes after the fifth decade of life. It is a highly represented phenomenon in older adults and in one-third of cases is “unexplained.” Ageing process is also characterized by a “multiple hormonal dysregulation” with disruption in gonadal, adrenal, and somatotropic axes. Experimental studies suggest that anabolic hormones such as testosterone, IGF-1, and thyroid hormones are able to increase erythroid mass, erythropoietin synthesis, and iron bioavailability, underlining a potential role of multiple hormonal changes in the anemia of aging. Epidemiological data more consistently support an association between lower testosterone and anemia in adult-older individuals. Low IGF-1 has been especially associated with anemia in the pediatric population and in a wide range of disorders. There is also evidence of an association between thyroid hormones and abnormalities in hematological parameters under overt thyroid and euthyroid conditions, with limited data on subclinical statuses. Although RCTs have shown beneficial effects, stronger for testosterone and the GH-IGF-1 axis and less evident for thyroid hormones, in improving different hematological parameters, there is no clear evidence for the usefulness of hormonal treatment in improving anemia in older subjects. Thus, more clinical and research efforts are needed to investigate the hormonal contribution to anemia in the older individuals.

  10. Hormone assay

    International Nuclear Information System (INIS)

    Eisentraut, A.M.

    1977-01-01

    An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

  11. The effects of thyroid hormones on brown adipose tissue in humans: a PET-CT study.

    Science.gov (United States)

    Zhang, Qiongyue; Miao, Qing; Ye, Hongying; Zhang, Zhaoyun; Zuo, Chuantao; Hua, Fengchun; Guan, Yihui; Li, Yiming

    2014-09-01

    Brown adipose tissue (BAT) is important for energy expenditure through thermogenesis, although its regulatory factors are not well known in humans. There is evidence suggesting that thyroid hormones affect BAT functions in some mammals, but the effects of thyroid hormones on BAT activity in humans are still unclear. The aim of this study was to investigate the effects of thyroid hormones on glucose metabolism of BAT and other organs in humans. Nine Graves' disease-caused hyperthyroid patients who were newly diagnosed and untreated were studied. Putative brown adipose tissue activity was determined by the integrated ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron-emission tomography and computed tomography (PET-CT). All hyperthyroid patients were treated with methimazole and had been monitored until their symptoms disappeared and thyroid hormone levels returned to normal. At the end, a second PET-CT scan was performed. The average follow-up period was 77 days. Meanwhile, compared with a group of seventy-five brown adipose tissue-negative controls, thyroid hormones of seventy-five BAT-positive healthy subjects were measured. Active brown adipose tissue was not present in any of the hyperthyroid patients. However, one patient with normalized thyroid function showed active BAT after therapy. The free T3 levels and free T4 levels were significantly lower in the 75 BAT-positive subjects than in the BAT-negative subjects. All hyperthyroid patients showed symmetrically increased uptake of fluorodeoxyglucose in skeletal muscles before treatment, whereas, the standardized uptake value was substantially decreased after treatment. Abnormally high circulating thyroid hormone levels may not increase brown adipose tissue activity, which may be limited by the increased obligatory thermogenesis of muscle in adult humans. Copyright © 2014 John Wiley & Sons, Ltd.

  12. WOMEN IN CANCER THEMATIC REVIEW: Thyroid-stimulating hormone in thyroid cancer: does it matter?

    Science.gov (United States)

    Nieto, Hannah; Boelaert, Kristien

    2016-11-01

    Differentiated thyroid cancer is the most common endocrine malignancy and the incidence is increasing rapidly worldwide. Appropriate diagnosis and post-treatment monitoring of patients with thyroid tumours are critical. Fine needle aspiration cytology remains the gold standard for diagnosing thyroid cancer, and although there have been significant refinements to this technique, diagnostic surgery is often required for patients suspected to have malignancy. Serum thyroid-stimulating hormone (TSH) is higher in patients with malignant thyroid nodules than in those with benign disease, and TSH is proportionally increased in more aggressive tumours. Importantly, we have shown that the pre-operative serum TSH concentration independently predicts the presence of malignancy in subjects presenting with thyroid nodules. Establishing the use of TSH measurements in algorithms identifying high-risk thyroid nodules in routine clinical practice represents an exciting, cost-efficient and non-invasive approach to optimise thyroid cancer diagnosis. Binding of TSH to receptors on thyrocytes stimulates a number of growth promoting pathways both in normal and malignant thyroid cells, and TSH suppression with high doses of levothyroxine is routinely used after thyroidectomy to prevent cancer recurrence, especially in high-risk tumours. This review examines the relationship between serum TSH and thyroid cancer and reflects on the clinical potential of TSH measurements in diagnosis and disease monitoring. © 2016 Society for Endocrinology.

  13. Thyroid hormone coordinately regulates Na sup + -K sup + -ATPase. alpha. - and. beta. -subunit mRNA levels in kidney

    Energy Technology Data Exchange (ETDEWEB)

    McDonough, A.A.; Brown, T.A.; Horowitz, B.; Chiu, R.; Schlotterbeck, J.; Bowen, J.; Schmitt, C.A. (Univ. of Southern California School of Medicine, Los Angeles (USA))

    1988-02-01

    Synthesis of the sodium pump, Na{sup +}-K{sup +}-ATPase, is regulated by thyroid hormone in responsive tissues. The purpose of this study was to determine if triiodothyronine (T{sub 3}) regulates the concentration of the mRNAs coding for the two enzyme subunits, {alpha} and {beta}, and the time course of the response. A single dose of T{sub 3} was administered to hypothyroid rats that were killed at various times after injection. In the kidney cortexes of the T{sub 3}-injected animals, as well as hypothyroid and euthyroid rats, {alpha}- and {beta}-mRNA concentrations were measured by dot blot using cDNAs corresponding to the two mRNAs; {alpha}-subunit abundance was measured by Western blot using antibodies to the enzyme, and Na{sup +}-K{sup +}-ATPase activity was measured enzymatically. {alpha}- and {beta}-mRNAs increased coordinately to 1.6-fold over hypothyroid levels by 12 h after T{sub 3}. The authors conclude that T{sub 3} regulates Na{sup +}-K{sup +}-ATPase synthesis and activity by coordinately increasing the mRNAs of both the {alpha}- and {beta}-subunits of the enzyme.

  14. Impaired transport of thyroid hormones into livers of obese (ob/ob) mice

    International Nuclear Information System (INIS)

    Hillgartner, F.B.; Romsos, D.R.

    1988-01-01

    Obese (ob/ob) mice exhibit impaired hepatic thyroid hormone action that is mediated, at least in part, by a reduced nuclear 3,5,3'-triiodothyronine (T 3 ) receptor occupancy. The possibility that lowered occupancy in obese mice may be caused by decreased transport of T 3 across the hepatic plasma membrane was examined by measuring the unidirectional influx of [ 125 I]T 3 into livers of 8- to 10-wk-old obese and lean mice using a tissue-sampling portal vein-injection technique. Influx of [ 125 I]thyroxine (T 4 ), a substrate for T 4 5'-deiodinase, was also measured. Unidirectional clearance of T 3 and T 4 was 64 and 80% lower, respectively, in obese mice than in lean mice. Hepatic T 3 and T 4 uptake was nonsaturable in both lean and obese mice, suggesting that transport occurs by lipid-mediated free diffusion. Clearance of another lipid-soluble hormone, hydrocortisone, was also lower in obese mice than in lean mice. Decreased membrane permeability to the above hormones in obese mice may result from reported changes in membrane lipid composition. In conclusion, decreased hepatic thyroid hormone uptake may contribute to impaired thyroid hormone action and T 3 production in livers of obese mice

  15. Methodologic and clinical aspects of free thyroid hormone assay

    International Nuclear Information System (INIS)

    Hermans, J.; Baldewyns, P.; Beauduin, M.

    1984-01-01

    The diagnostic value of free thyroid hormones measures depends on used technic. The results gived by two different kits are compared: - Kit Le Petit with chromatographic separation, - Kit Amersham which uses an analogue [fr

  16. The immediate and late effects of thyroid hormone (triiodothyronine) on murine coagulation gene transcription.

    Science.gov (United States)

    Salloum-Asfar, Salam; Boelen, Anita; Reitsma, Pieter H; van Vlijmen, Bart J M

    2015-01-01

    Thyroid dysfunction is associated with changes in coagulation. The aim of our study was to gain more insight into the role of thyroid hormone in coagulation control. C57Black/6J mice received a low-iodine diet and drinking water supplemented with perchlorate to suppress endogenous triiodothyronine (T3) and thyroxine (T4) production. Under these conditions, the impact of exogenous T3 on plasma coagulation, and hepatic and vessel-wall-associated coagulation gene transcription was studied in a short- (4 hours) and long-term (14 days) setting. Comparing euthyroid conditions (normal mice), with hypothyroidism (conditions of a shortage of thyroid hormone) and those with replacement by incremental doses of T3, dosages of 0 and 0.5 μg T3/mouse/day were selected to study the impact of T3 on coagulation gene transcription. Under these conditions, a single injection of T3 injection increased strongly hepatic transcript levels of the well-characterized T3-responsive genes deiodinase type 1 (Dio1) and Spot14 within 4 hours. This coincided with significantly reduced mRNA levels of Fgg, Serpinc1, Proc, Proz, and Serpin10, and the reduction of the latter three persisted upon daily treatment with T3 for 14 days. Prolonged T3 treatment induced a significant down-regulation in factor (F) 2, F9 and F10 transcript levels, while F11 and F12 levels increased. Activity levels in plasma largely paralleled these mRNA changes. Thbd transcript levels in the lung (vessel-wall-associated coagulation) were significantly up-regulated after a single T3 injection, and persisted upon prolonged T3 exposure. Two-week T3 administration also resulted in increased Vwf and Tfpi mRNA levels, whereas Tf levels decreased. These data showed that T3 has specific effects on coagulation, with Fgg, Serpinc1, Proc, Proz, Serpin10 and Thbd responding rapidly, making these likely direct thyroid hormone receptor targets. F2, F9, F10, F11, F12, Vwf, Tf and Tfpi are late responding genes and probably indirectly

  17. Kcne2 deletion uncovers its crucial role in thyroid hormone biosynthesis

    OpenAIRE

    Roepke, Torsten K.; King, Elizabeth C.; Reyna-Neyra, Andrea; Paroder, Monika; Purtell, Kerry; Koba, Wade; Fine, Eugene; Lerner, Daniel J.; Carrasco, Nancy; Abbott, Geoffrey W.

    2009-01-01

    Thyroid dysfunction affects 1?4% of the population worldwide, causing defects including neurodevelopmental disorders, dwarfism and cardiac arrhythmia. Here, we show that KCNQ1 and KCNE2 form a TSH-stimulated, constitutively-active, thyrocyte K+ channel required for normal thyroid hormone biosynthesis. Targeted disruption of Kcne2 impaired thyroid iodide accumulation up to 8-fold, impaired maternal milk ejection and halved milk T4 content, causing hypothyroidism, 50% reduced litter size, dwarf...

  18. Effects of Thyroid Dysfunction on Reproductive Hormones in Female Rats.

    Science.gov (United States)

    Liu, Juan; Guo, Meng; Hu, Xusong; Weng, Xuechun; Tian, Ye; Xu, Kaili; Heng, Dai; Liu, Wenbo; Ding, Yu; Yang, Yanzhou; Zhang, Cheng

    2018-05-10

    Thyroid hormones (THs) play a critical role in the development of ovarian cells. Although the effects of THs on female reproduction are of great interest, the mechanism remains unclear. We investigated the effects of TH dysregulation on reproductive hormones in rats. Propylthiouracil (PTU) and L-thyroxine were administered to rats to induce hypo- and hyper-thyroidism, respectively, and the reproductive hormone profiles were analyzed by radioimmunoassay. Ovarian histology was evaluated with H&E staining, and gene protein level or mRNA content was analyzed by western blotting or RT-PCR. The serum levels of gonadotropin releasing hormone (GnRH) and follicle stimulating hormone (FSH) in both rat models were significantly decreased on day 21, although there were no significant changes at earlier time points. There were no significant differences in luteinizing hormone (LH) or progesterone levels between the treatment and the control groups. Both PTU and L-thyroxine treatments downregulated estradiol concentrations; however, the serum testosterone level was increased only in hypothyroid rats at day 21. In addition, the expression levels of FSH receptor, cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic acute regulatory protein were decreased in both rat models. Moreover, the onset of puberty was significantly delayed in the hypothyroid group. These results provide evidence that TH dysregulation alters reproductive hormone profiles, and that the initiation of the estrous cycle is postponed in hypothyroidism.

  19. The effect of thyroid hormone and bone metablism-associated growth factor on the patients of hyperthyreosis

    International Nuclear Information System (INIS)

    Chen Wenhan; Xie Rongxing; Chen Shaozhu

    2008-01-01

    Objective: To evaluate the effect of high concentration of thyroid hormone and cell growth factor content on the bone metabolism of hyperthyreosis. Methods: Radiation immunological test and chemiluminescence methods are employed to determinate the content of free triiodothyronine (FT 3 ), free thyroxine (FT 4 ), thyroid stimulating hormone (TSH), insulin-like growth factor II(IGF-II), calcitonic (CT), interleukin-6 (IL-6) and tumor necrosis factor (TNF) of serum in health adult and parts of hyperthyreosis patients. Results: Hyperthyreosis patients have a higher content of FT 4 , FT 3 and IL-6 than those of health adult (t was 16.69,11.33,7.92, respectively, P<0.01), while the content of TSH, IGF-II, CT, TNF are obvious decreasing (t was 13.08, 8.34, 5.29, 8.75, respectively, P<0.01). Conclusion: In patients with hyperthyreosis, high concentration thyroid hormone cause accentuation of protein metabolism, decrease calcium homeostasis by disorders of phosphorus and calcium metabolism, high concentration thyroid hormone and low level CT resulted in bone loss. Decreased ICF-II may be the main cause of osteoporosis as the result of high concentration thyroid hormone. (authors)

  20. Regulation of porcine skeletal muscle nuclear 3,5,3'-tri-iodothyronine receptor binding capacity by thyroid hormones: modification by energy balance.

    Science.gov (United States)

    Morovat, A; Dauncey, M J

    1995-02-01

    Thyroid hormones have been implicated in the regulation of nuclear 3,5,3'-tri-iodothyronine (T3) receptor binding capacity (Bmax) but, despite numerous in vivo and in vitro studies, there is considerable controversy regarding their exact role. Since changes in thyroid status alter energy balance and hence may influence T3 receptor numbers, the effects of chronic hypothyroidism and T4 treatment have been studied in young pigs under conditions of controlled energy intake. Four groups of animals comprising a hypothyroid, a euthyroid and a hyperthyroid group, all on the same level of food intake, and a hyperthyroid group on twice the amount of food were used. After 3 weeks on the treatment regimes, both the hypothyroid animals on the same level of food intake and the hyperthyroid animals on twice the amount of food had significantly increased Bmax values (97% and 137% higher respectively) compared with euthyroid controls. However, there was no difference between controls and the hyperthyroid animals on the same level of food intake. In a second study, the effects of short-term treatment of euthyroid animals with T3 was investigated. Results showed that in two groups of controls that received intravenous saline, those on a higher food intake had higher Bmax values (76% increase). Intravenous T3 administration to animals on a low food intake did not change the receptor numbers. In none of the studies was there any change in the dissociation constant of the receptors as a result of different treatments. It is suggested that, at least in postnatal life, thyroid hormones per se have no significant effect on nuclear T3 receptor numbers in skeletal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Thyroid hormones and menstrual cycle function in a longitudinal cohort of premenopausal women.

    Science.gov (United States)

    Jacobson, Melanie H; Howards, Penelope P; Darrow, Lyndsey A; Meadows, Juliana W; Kesner, James S; Spencer, Jessica B; Terrell, Metrecia L; Marcus, Michele

    2018-03-08

    Previous studies have reported that hyperthyroid and hypothyroid women experience menstrual irregularities more often compared with euthyroid women, but reasons for this are not well-understood and studies on thyroid hormones among euthyroid women are lacking. In a prospective cohort study of euthyroid women, this study characterised the relationship between thyroid hormone concentrations and prospectively collected menstrual function outcomes. Between 2004-2014, 86 euthyroid premenopausal women not lactating or taking hormonal medications participated in a study measuring menstrual function. Serum thyroid hormones were measured before the menstrual function study began. Women then collected first morning urine voids and completed daily bleeding diaries every day for three cycles. Urinary oestrogen and progesterone metabolites (estrone 3-glucuronide (E 1 3G) and pregnanediol 3-glucuronide (Pd3G)) and follicle-stimulating hormone were measured and adjusted for creatinine (Cr). Total thyroxine (T 4 ) concentrations were positively associated with Pd3G and E 1 3G. Women with higher (vs lower) T 4 had greater luteal phase maximum Pd3G (Pd3G = 11.7 μg/mg Cr for women with high T 4 vs Pd3G = 9.5 and 8.1 μg/mg Cr for women with medium and low T 4 , respectively) and greater follicular phase maximum E 1 3G (E 1 3G = 41.7 ng/mg Cr for women with high T 4 vs E 1 3G = 34.3 and 33.7 ng/mg Cr for women with medium and low T 4 , respectively). Circulating thyroid hormone concentrations were associated with subtle differences in menstrual cycle function outcomes, particularly sex steroid hormone levels in healthy women. Results contribute to the understanding of the relationship between thyroid function and the menstrual cycle, and may have implications for fertility and chronic disease. © 2018 John Wiley & Sons Ltd.

  2. Transcriptional activation by the thyroid hormone receptor through ligand-dependent receptor recruitment and chromatin remodelling.

    Science.gov (United States)

    Grøntved, Lars; Waterfall, Joshua J; Kim, Dong Wook; Baek, Songjoon; Sung, Myong-Hee; Zhao, Li; Park, Jeong Won; Nielsen, Ronni; Walker, Robert L; Zhu, Yuelin J; Meltzer, Paul S; Hager, Gordon L; Cheng, Sheue-yann

    2015-04-28

    A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co-repressors and facilitates recruitment of co-activators to activate transcription. Here we show that in addition to hormone-independent TR occupancy, ChIP-seq against endogenous TR in mouse liver tissue demonstrates considerable hormone-induced TR recruitment to chromatin associated with chromatin remodelling and activated gene transcription. Genome-wide footprinting analysis using DNase-seq provides little evidence for TR footprints both in the absence and presence of hormone, suggesting that unliganded TR engagement with repressive complexes on chromatin is, similar to activating receptor complexes, a highly dynamic process. This dynamic and ligand-dependent interaction with chromatin is likely shared by all steroid hormone receptors regardless of their capacity to repress transcription in the absence of ligand.

  3. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development

    International Nuclear Information System (INIS)

    Veldhoen, Nik; Skirrow, Rachel C.; Osachoff, Heather; Wigmore, Heidi; Clapson, David J.; Gunderson, Mark P.; Van Aggelen, Graham; Helbing, Caren C.

    2006-01-01

    We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) α and β, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10 -11 mol/g body weight 3,5,3'-triiodothyronine (T 3 ) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10 nM T 3 . Tadpoles pretreated with triclosan concentrations as low as 0.15 ± 0.03 μg/L for 4 days showed increased hindlimb development and a decrease in total body weight following T 3 administration. Triclosan exposure also resulted in decreased T 3 -mediated TRβ mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T 3 treatment whereas TRα and BTEB were unaffected. Triclosan alone altered thyroid hormone receptor α transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T 3 plus nominal concentrations of triclosan as low as 0.03 μg/L for 24 h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development

  4. Selective thyroid hormone receptor modulators

    Directory of Open Access Journals (Sweden)

    Girish Raparti

    2013-01-01

    Full Text Available Thyroid hormone (TH is known to have many beneficial effects on vital organs, but its extrapolation to be used therapeutically has been restricted by the fact that it does have concurrent adverse effects. Recent finding of various thyroid hormone receptors (TR isoforms and their differential pattern of tissue distribution has regained interest in possible use of TH analogues in therapeutics. These findings were followed by search of compounds with isoform-specific or tissue-specific action on TR. Studying the structure-activity relationship of TR led to the development of compounds like GC1 and KB141, which preferentially act on the β1 isoform of TR. More recently, eprotirome was developed and has been studied in humans. It has shown to be effective in dyslipidemia by the lipid-lowering action of TH in the liver and also in obesity. Another compound, 3,5-diiodothyropropionic acid (DITPA, binds to both α- and β-type TRs with relatively low affinity and has been shown to be effective in heart failure (HF. In postinfarction models of HF and in a pilot clinical study, DITPA increased cardiac performance without affecting the heart rate. TR antagonists like NH3 can be used in thyrotoxicosis and cardiac arrhythmias. However, further larger clinical trials on some of these promising compounds and development of newer compounds with increased selectivity is required to achieve higher precision of action and avoid adverse effects seen with TH.

  5. Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland.

    Science.gov (United States)

    Katarzyńska, Dorota; Hrabia, Anna; Kowalik, Kinga; Sechman, Andrzej

    2015-03-01

    The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Analysis of thyroid hormones in biological samples using stable isotope dilution liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    This poster presentation will describe analytical chemistry methods for measuring thyroid hormones and related precursors and metabolites in very small tissue or plasma samples. These methods are amenable to measure thyroid hormones in amphibian tadpoles or small mammals used as ...

  7. Rat enterohepatic circulation and intestinal distribution of enterally infused thyroid hormones

    International Nuclear Information System (INIS)

    DiStefano, J.J. III; Sternlicht, M.; Harris, D.R.

    1988-01-01

    The enterohepatic circulation (recycling), intestinal (gut) distribution, metabolism, and excretion of enterally infused thyroid hormones were studied in the intact rat under approximately normal physiological steady state conditions. Rats with 7-day osmotic minipumps implanted ip received constant intraduodenal infusions to steady state of very small trace doses of either 125I-labeled T3 (T3*) or T4 (T4*). Enterohepatic and other pathways remained open to normal function, and in particular, there was no biliary diversion or ligation. Complete feces and urine were collected daily, to assess daily distributions of radioactivity and establishment of the steady state, which occurred by day 3. On day 7, rats were anesthetized, blood was sampled, whole intestine and minipumps were removed, and the gut was separated into six segments. Fecal samples and the contents of each gut section were homogenized, ethanol extracted, evaporated, and reconstituted in NaOH for quantitative aqueous chromatography along with infusate, urine, and plasma samples, on Sephadex G-25 columns. No T3* or T4* was found in urine, but feces contained 39% of the T3* infused and 36% of the T4* infused in steady state. Statistically significant amounts of both T3* and T4* in systemic plasma on day 7 clearly indicated absorption of the hormones from the intestine, distinctly demonstrating an enterohepatic circulation of T3 and T4 under experimental conditions closely approximating the physiological steady state. This also establishes the intestine (with its contents) as an exchangeable hormone pool, physiologically internal to the system regulating thyroid hormones and their distribution. Gut contents contained 52 times more T3* and 4.34 times more T4* than corresponding plasma pools in steady state

  8. Effects of 1-year growth hormone replacement therapy on thyroid volume and function of the children and adolescents with idiopathic growth hormone deficiency.

    Science.gov (United States)

    Keskin, Meliksah; Bayramoglu, Elvan; Aycan, Zehra

    2017-10-26

    There are different opinions about the effects of growth hormone replacement therapy (GHRT) on thyroid function and volume. This study aimed to assess the effects of GHRT on thyroid volume and function in the children and adolescents with growth hormone (GH) deficiency. A total of 29 patients diagnosed with GH deficiency were enrolled in the study. The control group consisted of 29 cases matched for age, gender and pubertal period with the patients. Thyroid function tests and insulin-like growth factor levels were measured, simultaneously thyroid volumes were assessed by ultrasonography at the initiation period and at the end of GHRT. Thyroid volumes of the patient group was -0.55±1.1 standard deviations (SDs) initially; whereas at the end of 1 year it was found to be -0.29±1.29 SDs and both SDs of thyroid volumes did not differ significantly. The SDs of thyroid volume of the control group was -0.85±1.03 SDs initially and -0.72±0.85 SDs at the end of 1 year; and they did not differ significantly. On the other hand, after GHRT of 1 year, thyroid stimulating hormone (TSH) and free thyroxine (T4) levels decreased. It was observed that SDs of thyroid gland volumes did not change in GH deficient children and adolescents after GHRT.

  9. A genome-wide association study of thyroid stimulating hormone and free thyroxine in Danish children and adolescents

    DEFF Research Database (Denmark)

    Nielsen, Tenna Ruest Haarmark; Appel, Emil Vincent Rosenbaum; Svendstrup, Mathilde

    2017-01-01

    BackgroundHypothyroidism is associated with obesity, and thyroid hormones are involved in the regulation of body composition, including fat mass. Genome-wide association studies (GWAS) in adults have identified 19 and 6 loci associated with plasma concentrations of thyroid stimulating hormone (TSH......) and free thyroxine (fT4), respectively.ObjectiveThis study aimed to identify and characterize genetic variants associated with circulating TSH and fT4 in Danish children and adolescents and to examine whether these variants associate with obesity.MethodsGenome-wide association analyses of imputed genotype...... data with fasting plasma concentrations of TSH and fT4 from a population-based sample of Danish children, adolescents, and young adults, and a group of children, adolescents, and young adults with overweight and obesity were performed (N = 1,764, mean age = 12.0 years [range 2.5-24.7]). Replication...

  10. Thyroid Hormone Role and Economy in the Developing Testis.

    Science.gov (United States)

    Hernandez, Arturo

    2018-01-01

    Thyroid hormones (TH) exhibit pleiotropic regulatory effects on growth, development, and metabolism, and it is becoming increasingly apparent that the developing testis is an important target for them. Testicular development is highly dependent on TH status. Both hypo- and hyperthyroidism affect testis size and the proliferation and differentiation of Sertoli, Leydig, and germ cells, with consequences for steroidogenesis, spermatogenesis, and male fertility. These observations suggest that an appropriate content of TH and by implication TH action in the testis, whether the result of systemic hormonal levels or regulatory mechanisms at the local level, is critical for normal testicular and reproductive function. The available evidence indicates the presence in the developing testis of a number of transporters, deiodinases and receptors that could play a role in the timely delivery of TH action on testicular cells. These include the thyroid hormone receptor alpha (THRA), the MCT8 transporter, the TH-activating deiodinase DIO2, and the TH-inactivating deiodinase DIO3, all of which appear to modulate testicular TH economy and testis outcomes. © 2018 Elsevier Inc. All rights reserved.

  11. Transcriptomic and phenotypic profiling in developing zebrafish exposed to thyroid hormone receptor agonists

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, Derik E.; Noyes, Pamela D.; Waters, Katrina M.; Tanguay, Robert L.

    2018-04-01

    There is a need to develop novel, high-throughput screening and prioritization methods to identify chemicals with adverse estrogen, androgen, and thyroid activity to protect human health and the environment and is of interest to the Endocrine Disruptor Screening Program. The current aim is to explore the utility of zebrafish as a testing paradigm to classify endocrine activity using phenotypically anchored transcriptome profiling. Transcriptome analysis was conducted on embryos exposed to 25 estrogen-, androgen-, or thyroid-active chemicals at a concentration that elicited adverse malformations or mortality at 120 hours post-fertilization in 80% of the animals exposed. Analysis of the top 1000 significant differentially expressed transcripts across all treatments identified a unique transcriptional and phenotypic profile for thyroid hormone receptor agonists, which can be used as a biomarker screen for potential thyroid hormone agonists.

  12. Clinical study on the changes of perioperative serum thyroid hormone during heart surgery

    International Nuclear Information System (INIS)

    Xu Zhonghua; Qian Yongyue; Liu Zengli; Wu Jinchang; Yang Chen

    2002-01-01

    To observe the changes of perioperative serum thyroid hormone and their clinical significance, blood samples were obtained from 20 patients before, during and after heart operations. Thyroid hormones were measured by radioimmunoassay. The results showed that serum T 3 , T 4 and FT 3 levels significantly declined during cardiopulmonary bypass (CPB) and thereafter. Serum T 3 and T 4 concentrations reached their nadir at the lowest hypothermia of CPB. TSH and FT 4 levels remained normal ranges at postoperative sampling times. Conclusions: CPB would severely affect patients' thyroid function, thus simulated a 'low T 3 syndrome', and low T 3 syndrome would produce side effects on postoperative heart function

  13. Novel neural pathways for metabolic effects of thyroid hormone

    NARCIS (Netherlands)

    Fliers, Eric; Klieverik, Lars P.; Kalsbeek, Andries

    2010-01-01

    The relation between thyrotoxicosis, the clinical syndrome resulting from exposure to excessive thyroid hormone concentrations, and the sympathetic nervous system remains enigmatic. Nevertheless, beta-adrenergic blockers are widely used to manage severe thyrotoxicosis. Recent experiments show that

  14. Placental Transfer of Perfluoroalkyl Substances and Associations with Thyroid Hormones: Beijing Prenatal Exposure Study

    Science.gov (United States)

    Yang, Lin; Li, Jingguang; Lai, Jianqiang; Luan, Hemi; Cai, Zongwei; Wang, Yibaina; Zhao, Yunfeng; Wu, Yongning

    2016-02-01

    Perfluoroalkyl substances (PFASs) have been detected in wildlife and human samples worldwide. Toxicology research showed that PFASs could interfere with thyroid hormone homeostasis. In this study, eight PFASs, fifteen PFAS precursors and five thyroid hormones were analyzed in 157 paired maternal and cord serum samples collected in Beijing around delivery. Seven PFASs and two precursors were detected in both maternal and cord sera with significant maternal-fetal correlations (r = 0.336 to 0.806, all P < 0.001). The median ratios of major PFASs concentrations in fetal versus maternal serum were from 0.25:1 (perfluorodecanoic acid, PFDA) to 0.65:1 (perfluorooctanoic acid, PFOA). Spearman partial correlation test showed that maternal thyroid stimulating hormone (TSH) was negatively correlated with most maternal PFASs (r = -0.261 to -0.170, all P < 0.05). Maternal triiodothyronin (T3) and free T3 (FT3) showed negative correlations with most fetal PFASs (r = -0.229 to -0.165 for T3; r = -0.293 to -0.169 for FT3, all P < 0.05). Our results suggest prenatal exposure of fetus to PFASs and potential associations between PFASs and thyroid hormone homeostasis in humans.

  15. [Painless thyroiditis].

    Science.gov (United States)

    Okamura, Ken; Fujikawa, Megumi; Bandai, Sachiko

    2006-12-01

    Painless thyroiditis is characterized by painless low-uptake thyrotoxicosis (thyrotoxicosis without hyperthyroidism). Destructive damage of the thyroid has been thought to be the mechanism for self-limited thyrotoxicosis. However, hydrolysis of thyroglobulin must be responsible for the release of excessive thyroid hormone. Low-uptake of iodine and excessive release of thyroid hormone suggest the uncoupling of hormone synthesis and hormone secretion in the thyroid gland. Suppressed serum TSH level, various cytokines or growth factors including TGFbeta1, and thyroglobulin itself may be responsible for the suppressed hormone synthesis. The mechanism for persistent hormone release despite suppressed hormone synthesis should be clarified. Quantitative TSH binding inhibitor immunoglobulin assay is helpful for the differential diagnosis of painless thyroiditis and Graves' hyperthyroidism.

  16. Thyroid hormone and adrenergic signaling interact to control pineal expression of the dopamine receptor D4 gene (Drd4)

    DEFF Research Database (Denmark)

    Kim, Jong-So; Bailey, Michael J; Weller, Joan L

    2009-01-01

    is circadian in nature and under photoneural control. Whereas most rhythmically expressed genes in the pineal are controlled by adrenergic/cAMP signaling, Drd4 expression also requires thyroid hormone. This advance raises the questions of whether Drd4 expression is regulated by this mechanism in other systems...

  17. Interferences in estimation of free thyroid hormones with special reference to antiiodothyronine autoantibodies in serum

    Energy Technology Data Exchange (ETDEWEB)

    Beck-Peccoz, P; Romelli, P B; Cattaneo, M G; Medri, G; Persani, L; Piscitelli, G; Faglia, G

    1985-11-01

    The aim of the present study is to evaluate the accuracy of the most commonly used 'new' techniques in some of the above circumstances. Particular emphasis will be placed on the possible interferences due to the presence of circulating antiiodothyronine autoantibodies (both anti-T/sub 4/ and anti-T/sub 3/), as, from a theoretical view point, the free thyroid hormone determination in this condition should be more appropriate than total thyroid hormone to correctly assess the thyroid state of the patient.

  18. Resistance to thyroid hormone associated with a novel mutation of the thyroid β receptor gene in a four-year-old female

    Directory of Open Access Journals (Sweden)

    Breuer Christopher K

    2011-06-01

    Full Text Available Abstract Resistance to thyroid hormone (RTH is a rare syndrome of reduced responsiveness of target tissues to thyroid hormone and is caused mutation in the thyroid β receptor gene. We report a novel mutation, E445X, causing RTH in a 4-year old girl. The patient exhibited extreme signs and symptoms of RTH at an early age, and had a large compressive goiter. Following total extracapsular thyroidectomy, upper airway compression was relieved and symptoms of hyperthyroidism improved. This case appears to be the youngest child recorded to have undergone total thyroidectomy for RTH. Post-operative TSH elevations were managed with every-other-day triiodothyronine therapy.

  19. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Nik [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Skirrow, Rachel C. [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Osachoff, Heather [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Wigmore, Heidi [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Clapson, David J. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Gunderson, Mark P. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Van Aggelen, Graham [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Helbing, Caren C. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada)]. E-mail: chelbing@uvic.ca

    2006-12-01

    We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) {alpha} and {beta}, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10{sup -11} mol/g body weight 3,5,3'-triiodothyronine (T{sub 3}) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10 nM T{sub 3}. Tadpoles pretreated with triclosan concentrations as low as 0.15 {+-} 0.03 {mu}g/L for 4 days showed increased hindlimb development and a decrease in total body weight following T{sub 3} administration. Triclosan exposure also resulted in decreased T{sub 3}-mediated TR{beta} mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T{sub 3} treatment whereas TR{alpha} and BTEB were unaffected. Triclosan alone altered thyroid hormone receptor {alpha} transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T{sub 3} plus nominal concentrations of triclosan as low as 0.03 {mu}g/L for 24 h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development.

  20. Thyroid-stimulating hormone elevation misdiagnosed as subclinical hypothyroidism following non-convulsive status epilepticus: a case report

    Directory of Open Access Journals (Sweden)

    Kunii Yasuto

    2011-09-01

    Full Text Available Abstract Introduction Non-convulsive status epilepticus is a form of epileptic seizure that occurs without convulsions. Recent reviews suggest that the diagnosis of non-convulsive status epilepticus remains difficult. Here, we report the case of a patient with thyroid-stimulating hormone elevation misdiagnosed as subclinical hypothyroidism following non-convulsive status epilepticus. Case presentation Our patient was a 68-year-old Japanese woman. The results of endocrine testing after her first episode of non-convulsive status epilepticus suggested latent subclinical hypothyroidism: she had elevated thyroid-stimulating hormone with normal levels of free tri-iodothyronine and free thyroxine. On examination, a diagnosis of thyroid disorder was not supported by other test results and our patient remained untreated. A follow-up examination revealed that her thyroid-stimulating hormone levels had spontaneously normalized. When she consulted another doctor for confusion, the transient increase in thyroid-stimulating hormone levels following non-convulsive status epilepticus was mistaken for subclinical hypothyroidism, and unfortunately treated with levothyroxine. Our patient then experienced levothyroxine-induced non-convulsive status epilepticus. Conclusions In this report, we suggested possible mechanisms for latent hypothyroid-like hormone abnormality following epileptic seizures and the possibility of provoking epileptic seizures by administering levothyroxine for misdiagnosed subclinical hypothyroidism.

  1. Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

    International Nuclear Information System (INIS)

    Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

    1987-01-01

    Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

  2. Clinical significance of bone metabolic parameters and serum thyroid hormone levels in patients with hyperthyroidism

    International Nuclear Information System (INIS)

    Xiao Jinhua; Wang Yaping; Sun Junming; Hua Wenjing

    2002-01-01

    To study the changes in bone metabolic parameters and serum thyroid hormone levels in patients with hyperthyroidism, seventy patients with hyperthyroidism and sixty healthy controls were investigated by means of radioimmunoassay (RIA) for serum ICTP, chemiluminescent immunoassay for BAP and serum thyroid hormone and meanwhile bone mineral density was measured. The results showed that the levels of serum BAP, ICTP and thyroid hormone in patients with hyperthyroidism were dramatically higher than those in control group (all P<0.01), BMD was significantly decreased in the study group (P<0.01). The correlation analysis showed that both BAP and ICTP were negatively correlated with BMD (all P<0.05). The results from this investigation indicated that increased bone turnover is significantly associated with an increased thyroid hormone in patients with hyperthyroidism, and bone resorption is greater than formation resulting in a bone mass loss. Measurement of serum BAP and ICTP levels may be of help to judge the severity of bone metabolism, study the state of an illness in hyperthyroidism

  3. Methylation of the thyroid stimulating hormone receptor: diagnostic marker of malignity in thyroid cancer

    International Nuclear Information System (INIS)

    Marrero Rodriguez, Maria Teresa

    2007-01-01

    The methylation state of the gene promoter for the receptor of the thyroid stimulating hormone (TSH) in the diagnosis of thyroid tumors of epithelial origin was analyzed. The study was conducted in thyroid tissue obtained from paraffin blocks of different thyroid pathologies (papillary, follicular and undifferentiated carcinoma and follicular adenomas). The work was done by using the DNA modification technique with sodium bisulfite, and polymerase chain reaction was applied to analyze the gene methylation state. Methylation of the promoter for the gene of the TSH receptor was found in the papillary carcinomas (33 of 40; 82.5 %), in 10 undifferentiated carcinomas (100 %), and in 10 of the 15 follicular carcinomas analyzed (66.6 %). No methylation was observed in the 8 follicular adenomas under study. The methylation of the gene for the TSH receptor was proposed as a new diagnostic marker of malignity and as a basis for using demethylating agents together with radioiodine therapy in patients with thyroid cancer of epithelial origin that do not respond to therapy. (Author)

  4. Hormonal causes of male sexual dysfunctions and their management (hyperprolactinemia, thyroid disorders, GH disorders, and DHEA).

    Science.gov (United States)

    Maggi, Mario; Buvat, Jaques; Corona, Giovanni; Guay, André; Torres, Luiz Otavio

    2013-03-01

    Besides hypogonadism, other endocrine disorders have been associated with male sexual dysfunction (MSD). To review the role of the pituitary hormone prolactin (PRL), growth hormone (GH), thyroid hormones, and adrenal androgens in MSD. A systematic search of published evidence was performed using Medline (1969 to September 2011). Oxford Centre for Evidence-Based Medicine-Levels of Evidence (March 2009) was applied when possible. The most important evidence regarding the role played by PRL, GH, thyroid, and adrenal hormone was reviewed and discussed. Only severe hyperprolactinemia (>35 ng/mL or 735 mU/L), often related to a pituitary tumor, has a negative impact on sexual function, impairing sexual desire, testosterone production, and, through the latter, erectile function due to a dual effect: mass effect and PRL-induced suppression on gonadotropin secretion. The latter is PRL-level dependent. Emerging evidence indicates that hyperthyroidism is associated with an increased risk of premature ejaculation and might also be associated with erectile dysfunction (ED), whereas hypothyroidism mainly affects sexual desire and impairs the ejaculatory reflex. However, the real incidence of thyroid dysfunction in subjects with sexual problems needs to be evaluated. Prevalence of ED and decreased libido increase in acromegalic patients; however, it is still a matter of debate whether GH excess (acromegaly) may create effects due to a direct overproduction of GH/insulin-like growth factor 1 or because of the pituitary mass effects on gonadotropic cells, resulting in hypogonadism. Finally, although dehydroepiandrosterone (DHEA) and its sulfate have been implicated in a broad range of biological derangements, controlled trials have shown that DHEA administration is not useful for improving male sexual function. While the association between hyperprolactinemia and hypoactive sexual desire is well defined, more studies are needed to completely understand the role of other hormones in

  5. Association between organophosphate pesticides exposure and thyroid hormones in floriculture workers

    International Nuclear Information System (INIS)

    Lacasana, Marina; Lopez-Flores, Inmaculada; Rodriguez-Barranco, Miguel; Aguilar-Garduno, Clemente; Blanco-Munoz, Julia; Perez-Mendez, Oscar; Gamboa, Ricardo; Bassol, Susana; Cebrian, Mariano E.

    2010-01-01

    The ability of organophosphate pesticides to disturb thyroid gland function has been demonstrated by experimental studies on animal, but evidence of such effects on human remains scarce. The aim of this study was to assess the association between exposure to organophosphate compounds and serum levels of thyroid hormones in floriculture workers. A longitudinal study was conducted on 136 male subjects from the State of Mexico and Morelos, Mexico, occupationally exposed to organophosphate pesticides, during agricultural periods of high (rainy season) and low (dry season) levels of pesticide application. Using a structured questionnaire, a survey was carried out on sociodemographic characteristics, anthropometry, clinical history, alcohol and tobacco consumption, residential chemical exposure, and occupational history. Urine and blood samples were taken the day after pesticide application to determine urine dialkylphosphate (DAP) levels, serum levels of TSH, total T 3 , total T 4 , serum PON1 activity, and serum p,p'-DEE levels. The analysis of the association between DAP levels and thyroid hormonal profile was carried out using multivariate generalized estimating equation (GEE) models. Our results showed an increase in both TSH and T 4 hormones in serum associated with a increase in total dimethylphosphate levels (ΣDMP) in urine (p-trend 3 serum levels with an increase of ΣDMP levels in the urine (p-trend = 0.053). These results suggest that exposure to organophosphate pesticides may be responsible of increasing TSH and T 4 serum hormone levels and decreasing T 3 serum hormone levels, therefore supporting the hypothesis that organophosphate pesticides act as endocrine disruptors in humans.

  6. Near-lethal respiratory failure after recombinant human thyroid-stimulating hormone use in a patient with metastatic thyroid carcinoma.

    Science.gov (United States)

    Goffman, Thomas; Ioffe, Vladimir; Tuttle, Michael; Bowers, John T; Mason, M Elizabeth

    2003-08-01

    A patient with widely metastatic differentiated thyroid cancer who had been heavily pretreated with (131)I was given recombinant human thyroid stimulating hormone (rhTSH) prior to (131)I treatment. Clinical and physical data from both this case and the literature suggest that the recombinant hormone, not the (131)I, may have caused a significant portion of the tumor swelling, which in turn was the most likely cause of the patient's symptoms. The potential effect of (131)I-induced tumor swelling and direct radiation effect on the lung is also analyzed. We review the potential hazards associated with rhTSH in patients with metastasis and propose means of minimizing this risk.

  7. Quantitative Adverse Outcome Pathway for Neurodevelopmental Effects of Thyroid Peroxidase-Induced Thyroid Hormone Synthesis Inhibition

    Science.gov (United States)

    Adequate levels of thyroid hormones (TH) are needed for proper brain development and deficiencies lead to adverse neurological outcomes in humans and in animal models. Environmental chemicals have been shown to disrupt TH levels, yet the relationship between developmental exposur...

  8. Interrelation of hormonal regulation parameters and metabolic processes in children from the families with radiation risk

    International Nuclear Information System (INIS)

    Korenjev, M.M.; Kashkalda, D.A.; Borisko, G.O.; Cherevatova, S.Kh.; Bondarenko, V.A.; Kalmikova, N.V.; Spyivak, T.V.

    2010-01-01

    Interrelations of the indices of lipid peroxidation and antioxidant system with hormone level were investigated in teenagers born from the parents who participated in Chornobyl accident clean-up. Multiple inter-systemic relations indicating participation of hormonal regulation mechanisms in promotion of redox processes were revealed. In girls from the families of Chornobyl accident clean-up participants, LP and AOP processes dependent significantly on the level of steroid hormones. In boys, the relations with thyroid system dominated.

  9. Effect of salinity level on TSH and thyroid hormones of grass carp, Ctenophayngodon idella

    Directory of Open Access Journals (Sweden)

    Rahim Peyghan

    2013-09-01

    Full Text Available Thyroid hormones (T3, T4 have marked effect on body metabolism and in controlling osmoregulation activity in fish. The aim of this study was to determine the effect of water salinity changes on thyroid hormones level and thyroid-stimulating hormone (TSH of grass carp. For this purpose 120 grass carp were divided randomly in to four groups (10 fish in each group and three replicates per treatment. Three groups were held in three different salinities at concentrations of 4, 8 and 12 g L-1. The fourth group was reared in fresh water and considered as control. After three weeks blood samples were collected from the caudal peduncle vein. Then serum was separated and serum thyroid hormones and TSH were measured by LISA on Microwell plates. Our results indicated that the average of T3 levels in 4, 8 and 12 g L-1 groups were 0.43 ± 0.11, 0.22 ± 0.04 and 0.21 ± 0.04 μg dL-1, respectively. T3 levels in all experimental groups were significantly lower than those of control group (p 0.05. The level of TSH in salinities of 4 and 8 g L-1 groups was significantly higher than that of control group (p < 0.05. The results showed that increasing water salinity can have significant effect on thyroid activity by decreasing T3 and increasing T4 level in serum of grass carp in experimental condition.

  10. [Thyroid emergencies : Thyroid storm and myxedema coma].

    Science.gov (United States)

    Spitzweg, C; Reincke, M; Gärtner, R

    2017-10-01

    Thyroid emergencies are rare life-threatening endocrine conditions resulting from either decompensated thyrotoxicosis (thyroid storm) or severe thyroid hormone deficiency (myxedema coma). Both conditions develop out of a long-standing undiagnosed or untreated hyper- or hypothyroidism, respectively, precipitated by an acute stress-associated event, such as infection, trauma, or surgery. Cardinal features of thyroid storm are myasthenia, cardiovascular symptoms, in particular tachycardia, as well as hyperthermia and central nervous system dysfunction. The diagnosis is made based on clinical criteria only as thyroid hormone measurements do not differentiate between thyroid storm and uncomplicated hyperthyroidism. In addition to critical care measures therapy focusses on inhibition of thyroid hormone synthesis and secretion (antithyroid drugs, perchlorate, Lugol's solution, cholestyramine, thyroidectomy) as well as inhibition of thyroid hormone effects in the periphery (β-blocker, glucocorticoids).Cardinal symptoms of myxedema coma are hypothermia, decreased mental status, and hypoventilation with risk of pneumonia and hyponatremia. The diagnosis is also purely based on clinical criteria as measurements of thyroid hormone levels do not differ between uncomplicated severe hypothyroidism and myxedema coma. In addition to substitution of thyroid hormones and glucocorticoids, therapy focusses on critical care measures to treat hypoventilation and hypercapnia, correction of hyponatremia and hypothermia.Survival of both thyroid emergencies can only be optimized by early diagnosis based on clinical criteria and prompt initiation of multimodal therapy including supportive measures and treatment of the precipitating event.

  11. The role of thyroid hormone calorigenesis in the redox regulation of gene expression

    Directory of Open Access Journals (Sweden)

    PATRICIA VARELA

    2006-01-01

    Full Text Available Thyroid hormone (TH; 3,3',5-triiodothyronine, T3 is required for the normal function of most tissues, with major effects on 0(2 consumption and metabolic rate. These are due to transcriptional activation of respiratory genes through the interaction of T3-liganded TH receptors with TH response elements or the activation of intermediate factors, with the consequent higher production of reactive 0(2 species (ROS and antioxidant depletion. T3-induced oxidative stress in the liver triggers the redox upregulation of the expression of cytokines (tumor necrosis factor-á [TNF-á], interleukin-10, enzymes (inducible nitric oxide synthase, manganese superoxide dismutase, and anti-apoptotic proteins (Bcl-2, via a cascade initiated by TNF-á produced by Kupffer cells, involving inhibitor of κB phosphorylation and nuclear factor-κB activation. Thus, TH calorigenesis triggers an expression pattern that may represent an adaptive mechanism to re-establish redox homeostasis and promote cell survival under conditions of ROS toxicity secondary to TH-induced oxidative stress. Mechanisms of expression of respiratory and redox-sensitive genes may be functionally integrated, which could be of importance to understand the complexities of TH action and the outcome of thyroid gland dysfunction

  12. Do unliganded thyroid hormone receptors have physiological functions?

    Science.gov (United States)

    Chassande, O

    2003-08-01

    Thyroid hormone (TH) is required for the development of vertebrates and exerts numerous homeostatic functions in adults. TH acts through nuclear receptors which control the transcription of target genes. Unliganded and liganded thyroid hormone receptors (TRs) have been shown to exert opposite effects on the transcription of target genes in vitro. However, the occurance of an aporeceptor activity in vivo and its potential physiological significance has not been clearly addressed. Several data generated using experimental hypothyroidism and thyrotoxicosis in wild type and TR knockout mice support the notion that apoTRs have an intrinsic activity in several tIssues. ApoTRs, and in particular TRalpha1, are predominant during the early stages of vertebrate development and must be turned into holoTRs for post-natal development to proceed normally. However, the absence of striking alterations of embryonic and fetal development in mice devoid of TRs indicates that apoTRs do not play a fundamental role. During development, as well as in adults, apoTRs rather appears as a system which increases the range of transcriptional responses to moderate variations of T3.

  13. Evaluation of two over-the-counter natural thyroid hormone preparations in human volunteers.

    Science.gov (United States)

    Csako, G; Corso, D M; Kestner, J; Bokser, A D; Kennedy, P E; Pucino, F

    1992-04-01

    To determine the pharmacologic activity of over-the-counter (OTC) thyroid preparations. In vitro analysis and a prospective, crossover study in vivo. Tertiary care center. Two healthy adult volunteers. Three OTC preparations (Thyrotrophin PMG [bovine thyroid PMG extract], Thyro Forte [thyroid lymphogland concentrate with synergistic complex], and Thyro Complex [thyroid lyophilized gland concentrate with synergistic complex]) were analyzed in vitro. Volunteers were administered two times the manufacturer's maximum recommended daily dose of either Thyrotrophin PMG or Thyro Forte for one week, washed out for four to five weeks, and crossed over to receive the opposite tablet preparation for an additional week. The triiodothyronine (T3) and thyroxine (T4) contents of OTC preparations were measured by HPLC. Vital signs, serum total and free T4, total T3, thyroid stimulating hormone, thyroxine binding globulin, thyroglobulin, and general chemistry tests (including glucose and cholesterol) were monitored before, during, and between administration of the products. HPLC analysis of the three OTC preparations showed no T4 but did show possible T3 in two of these products. We found no definite clinical or laboratory evidence of thyroid hormone excess with either product. Healthcare professionals should advise against the use of these scientifically unsound and relatively expensive OTC thyroid preparations, of which the therapeutic efficacy is unknown.

  14. Effects of graded doses of goitrin, a goitrogen in rapeseed, on synthesis and release of thyroid hormone in chicks

    International Nuclear Information System (INIS)

    Akiba, Yukio; Matsumoto, Tatsuro

    1977-01-01

    Intrathyroidal metabolism in synthesis and release of thyroid hormone was investigated in chicks administered three different levels of goitrin (0.0125, 0.025 and 0.05% in the diet) for 14 days. Thyroid glands were enlarged to 2-5 times as large as that of the control in proportion to the goitrin content of the diet. Typical high radioiodine uptake goiter was demonstrated in the goitrin-administered chicks. Total thyroid 125 I content increased about twice as much as that of the control in the goitrin-administered chicks though it was depressed in 0.0065% PUT-administered chicks. Decrease of plasma PB 125 I (approximately a half of the control) was ascertained by the estimation of plasma thyroxine by radiostereoassay. In the intrathyroidal metabolism of iodine, synthesis of iodothyronines and iodination of MIT were suppressed by goitrin, but monoiodination of tyrosine was rather accelerated. The elevated ratio of thyroid iodothyronines/plasma PBI (1.5-1.7 times as much as that of the control) reveals that the depression of plasma level of thyroid hormone is more striking than the decrease in thyroid hormone in the gland in the goitrin-administered chicks. It is, therefore, suggested that goitrin has inhibitory effects not only on the biosynthesis of thyroid hormone in the gland but also on the release of thyroid hormone from the gland. (auth.)

  15. Thyroid hormone levels in patients with chronic renal failure under haemodialysis

    International Nuclear Information System (INIS)

    Khalid, Ahmed Shukralla M.

    1998-06-01

    This study was conducted with three main objectives, to study thyroid hormones (T 4 , T 3 ) and TSH levels in patients with CRF under haemodialysis and to compare them with normal subjects, to study best means of treatment and to compare these findings with results from other parts of the world. This study was done on 61 patients with renal failure in Khartoum dialysis and kidney transplant centre U of K, 45 males and 16 females with ages ranging from 17-75 years and 42 symptoms-free subjects 14 males and 23 females with age ranging from 16-60 years. The radioimmunoassay (RIA) technique was used for the determination of serum T 4 , T 3 and TSH. By using t-test found that the mean concentrations of T 4 , T 3 of normal subjects were much higher than those of the patients (p 0.05). These results also illustrated that 45.9% of patients with renal failure of low T 4 , and 91.8%, 90.26 of patients had T 3 and TSH hormone levels in the normal range, respectively. No significant difference was observed in the mean of thyroid hormones (T 4 , T 3 ) and thyroid-stimulating hormones between males and females (p>0.05). The T 3 and T '4 concentrations in patients at all age groups (year) was less than the age groups of the control group, and this decrease was statistically significant (p 0.05).(Author)

  16. Methimazole-Induced Goitrogenesis in an Adult Patient With the Syndrome of Resistance to Thyroid Hormone

    Directory of Open Access Journals (Sweden)

    Kathleen Glymph DO

    2014-10-01

    Full Text Available Patients with the syndrome of resistance to thyroid hormone (RTH have clinical (tachycardia and anxiety and biochemical (elevated thyroid hormones level features of hyperthyroidism. Based on previous reports in pediatric patients with the RTH, antithyroid treatment in these patients is not indicated. Clinical and biochemical sequel of antithyroid therapy in an adult patient with RTH was not previously reported. A 63-year-old African American female with history of RTH was treated with a therapy consisting of methimazole 15 mg daily and atenolol. Methimazole treatment resulted in reduction in thyroid hormone level while the patient’s TSH increased with a peak of 24.88 mIU/L. Having achieved biochemical euthyroidism, the patient developed thyroid gland enlargement associated with progressive symptoms of dysphagia and dyspnea. Examination demonstrated globally enlarged firm thyroid gland with areas of nodularity in both lobes. A computed tomography of the neck showed enlarged thyroid gland with extension around bilateral sternocleidomastoid muscles and compression onto the trachea. Methimazole therapy was discontinued and patient was treated just on atenolol. Over 12 months following discontinuation of methimazole, the patient experienced marked clinical and radiographic improvement of the goiter size associated with TSH reduction to 1.26 mIU/L and modest free thyroxine increase as expected in RTH. It seems appealing to treat patients with the RTH with antithyroid medications. However, in these patients decrease in thyroid hormone levels will stimulate TSH production, which can, in turn, predispose to goiter formation. Our report supports prior observations in children with RTH that treatment with methimazole is not indicated in adult patients with RTH.

  17. A meta-analysis of thyroid-related traits reveals novel loci and gender-specific differences in the regulation of thyroid function.

    Directory of Open Access Journals (Sweden)

    Eleonora Porcu

    Full Text Available Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3 and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2. Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2 show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64% and 2.30% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism.

  18. A Meta-Analysis of Thyroid-Related Traits Reveals Novel Loci and Gender-Specific Differences in the Regulation of Thyroid Function

    Science.gov (United States)

    Volpato, Claudia B.; Wilson, Scott G.; Cappola, Anne R.; Bos, Steffan D.; Deelen, Joris; den Heijer, Martin; Freathy, Rachel M.; Lahti, Jari; Liu, Chunyu; Lopez, Lorna M.; Nolte, Ilja M.; O'Connell, Jeffrey R.; Tanaka, Toshiko; Trompet, Stella; Arnold, Alice; Bandinelli, Stefania; Beekman, Marian; Böhringer, Stefan; Brown, Suzanne J.; Buckley, Brendan M.; Camaschella, Clara; de Craen, Anton J. M.; Davies, Gail; de Visser, Marieke C. H.; Ford, Ian; Forsen, Tom; Frayling, Timothy M.; Fugazzola, Laura; Gögele, Martin; Hattersley, Andrew T.; Hermus, Ad R.; Hofman, Albert; Houwing-Duistermaat, Jeanine J.; Jensen, Richard A.; Kajantie, Eero; Kloppenburg, Margreet; Lim, Ee M.; Masciullo, Corrado; Mariotti, Stefano; Minelli, Cosetta; Mitchell, Braxton D.; Nagaraja, Ramaiah; Netea-Maier, Romana T.; Palotie, Aarno; Persani, Luca; Piras, Maria G.; Psaty, Bruce M.; Räikkönen, Katri; Richards, J. Brent; Rivadeneira, Fernando; Sala, Cinzia; Sabra, Mona M.; Sattar, Naveed; Shields, Beverley M.; Soranzo, Nicole; Starr, John M.; Stott, David J.; Sweep, Fred C. G. J.; Usala, Gianluca; van der Klauw, Melanie M.; van Heemst, Diana; van Mullem, Alies; H.Vermeulen, Sita; Visser, W. Edward; Walsh, John P.; Westendorp, Rudi G. J.; Widen, Elisabeth; Zhai, Guangju; Cucca, Francesco; Deary, Ian J.; Eriksson, Johan G.; Ferrucci, Luigi; Fox, Caroline S.; Jukema, J. Wouter; Kiemeney, Lambertus A.; Pramstaller, Peter P.; Schlessinger, David; Shuldiner, Alan R.; Slagboom, Eline P.; Uitterlinden, André G.; Vaidya, Bijay; Visser, Theo J.; Wolffenbuttel, Bruce H. R.; Meulenbelt, Ingrid; Rotter, Jerome I.; Spector, Tim D.; Hicks, Andrew A.; Toniolo, Daniela; Sanna, Serena; Peeters, Robin P.; Naitza, Silvia

    2013-01-01

    Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3) and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2). Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2) show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64% and 2.30% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism. PMID:23408906

  19. Thyroid Hormone in the CNS: Contribution of Neuron-Glia Interaction.

    Science.gov (United States)

    Noda, Mami

    2018-01-01

    The endocrine system and the central nervous system (CNS) are intimately linked. Among hormones closely related to the nervous system, thyroid hormones (THs) are critical for the regulation of development and differentiation of neurons and neuroglia and hence for development and function of the CNS. T3 (3,3',5-triiodothyronine), an active form of TH, is important not only for neuronal development but also for differentiation of astrocytes and oligodendrocytes, and for microglial development. In adult brain, T3 affects glial morphology with sex- and age-dependent manner and therefore may affect their function, leading to influence on neuron-glia interaction. T3 is an important signaling factor that affects microglial functions such as migration and phagocytosis via complex mechanisms. Therefore, dysfunction of THs may impair glial function as well as neuronal function and thus disturb the brain, which may cause mental disorders. Investigations on molecular and cellular basis of hyperthyroidism and hypothyroidism will help us to understand changes in neuron-glia interaction and therefore consequent psychiatric symptoms. © 2018 Elsevier Inc. All rights reserved.

  20. Obtaining of stimulating hormone of the thyroid (hTSH) of Human Hypophysis

    International Nuclear Information System (INIS)

    Ayala, Jorge H; Carvajal G, Claudia; Anzola V, Cecilia; Gomez de, Myrian

    1993-01-01

    Thyroid-stimulating hormone (TSH) was extracted from human frozen pituitary glands using a method for the integral extraction of most hormones present in the gland. A specific immunoradiometric method (IRMA) was standardized and used for the analysis of TSH content. The immunology potency of the final TSH preparation was 1365 mUI/mg by IRMA. Characterization by SDS-PAGE demonstrated the multicomponent nature of the hormone

  1. Vascular and renal function in experimental thyroid disorders.

    Science.gov (United States)

    Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

    2006-02-01

    This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

  2. A genome-wide association study of thyroid stimulating hormone and free thyroxine in Danish children and adolescents

    DEFF Research Database (Denmark)

    Nielsen, Tenna Ruest Haarmark; Appel, Emil Vincent Rosenbaum; Svendstrup, Mathilde

    2017-01-01

    BackgroundHypothyroidism is associated with obesity, and thyroid hormones are involved in the regulation of body composition, including fat mass. Genome-wide association studies (GWAS) in adults have identified 19 and 6 loci associated with plasma concentrations of thyroid stimulating hormone (TSH...... data with fasting plasma concentrations of TSH and fT4 from a population-based sample of Danish children, adolescents, and young adults, and a group of children, adolescents, and young adults with overweight and obesity were performed (N = 1,764, mean age = 12.0 years [range 2.5-24.7]). Replication...... associated with TSH in adults were confirmed in this study population (PDE10A (rs2983511: beta = 0.112SD, p = 4.8.10(-16)), FOXE1 (rs7847663: beta = 0.223SD, p = 1.5 . 10(-20)), NR3C2 (rs9968300: beta = 0.194SD), p = 2.4 . 10(-11)), VEGFA (rs2396083: beta = 0.088SD, p = 2.2 . 10(-10))). Effect sizes...

  3. (−) Arctigenin and (+) Pinoresinol Are Antagonists of the Human Thyroid Hormone Receptor β

    Science.gov (United States)

    2015-01-01

    Lignans are important biologically active dietary polyphenolic compounds. Consumption of foods that are rich in lignans is associated with positive health effects. Using modeling tools to probe the ligand-binding pockets of molecular receptors, we found that lignans have high docking affinity for the human thyroid hormone receptor β. Follow-up experimental results show that lignans (−) arctigenin and (+) pinoresinol are antagonists of the human thyroid hormone receptor β. The modeled complexes show key plausible interactions between the two ligands and important amino acid residues of the receptor. PMID:25383984

  4. Thyroid disorders in Multan, Pakistan, and hormone levels during Ramadan

    International Nuclear Information System (INIS)

    Khan, S.M.; Abbas, H.G.; Sabih, D.E.

    1986-01-01

    Patients with thyroid disorders were analyzed in 1984 with respect to their clinical state, thyroid hormone levels in the blood and the speciality of the referring clinician. There were 815 patients (304 men, 511 women) with ages from 3 months to 80 years. Analysis showed that 310 (38%) of the patients were euthyroid without goitre, the male:female ratio being 3:2; 260 (31.9%) of the patients were euthyroid with goitre, the male:female ratio being 1:5; 61 (7.5%) patients were hypothyroid, with a male:female ratio of 3:4; 175 (21.5%) were thyrotoxic, the ratio being 1:3; and 9 (1.1%) had thyroid carcinoma, the ratio being 1:2. Sources of referral were also taken into account. In June of the same year, another study was conducted to find the effect of fasting on various hormones during Ramadan. One female and 32 male volunteers without thyroid disorders, between 12 and 65 years of age, gave blood samples. Each volunteer gave two blood samples: the first was collected during fasting and the second after fasting. Serum T 3 , T 4 and prolactin (PRL) were measured using radioimmunoassay. Statistical analysis showed that variations in T 3 and T 4 were not significant but that there was a significant increase in PRL during fasting (p<0.05). (author)

  5. Exercise training versus T3 and T4 hormones treatment: The differential benefits of thyroid hormones on the parasympathetic drive of infarcted rats.

    Science.gov (United States)

    Teixeira, Rayane Brinck; Zimmer, Alexsandra; de Castro, Alexandre Luz; Carraro, Cristina Campos; Casali, Karina Rabello; Dias, Ingrid Gonçalves Machuca; Godoy, Alessandra Eifler Guerra; Litvin, Isnard Elman; Belló-Klein, Adriane; da Rosa Araujo, Alex Sander

    2018-03-01

    This study aimed to investigate whether beneficial effects of thyroid hormones are comparable to those provided by the aerobic exercise training, to verify its applicability as a therapeutic alternative to reverse the pathological cardiac remodeling post-infarction. Male rats were divided into SHAM-operated (SHAM), myocardial infarction (MI), MI subjected to exercise training (MIE), and MI who received T3 and T4 treatment (MIH) (n = 8/group). MI, MIE and MIH groups underwent an infarction surgery while SHAM was SHAM-operated. One-week post-surgery, MIE and MIH groups started the exercise training protocol (moderate intensity on treadmill), or the T3 (1.2 μg/100 g/day) and T4 (4.8 μg/100 g/day) hormones treatment by gavage, respectively, meanwhile SHAM and MI had no intervention for 9 weeks. The groups were accompanied until 74 days after surgery, when all animals were anesthetized, left ventricle echocardiography and femoral catheterization were performed, followed by euthanasia and left ventricle collection for morphological, oxidative stress, and intracellular kinases expression analysis. Thyroid hormones treatment was more effective in cardiac dilation and infarction area reduction, while exercise training provided more protection against fibrosis. Thyroid hormones treatment increased the lipoperoxidation and decreased GSHPx activity as compared to MI group, increased the t-Akt2 expression as compared to SHAM group, and increased the vascular parasympathetic drive. Thyroid hormones treatment provided differential benefits on the LV function and autonomic modulation as compared to the exercise training. Nevertheless, the redox unbalance induced by thyroid hormones highlights the importance of more studies targeting the ideal duration of this treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Thyroid-Stimulating Hormone Receptor Antibodies in Pregnancy: Clinical Relevance

    Science.gov (United States)

    Bucci, Ines; Giuliani, Cesidio; Napolitano, Giorgio

    2017-01-01

    Graves’ disease is the most common cause of thyrotoxicosis in women of childbearing age. Approximately 1% of pregnant women been treated before, or are being treated during pregnancy for Graves’ hyperthyroidism. In pregnancy, as in not pregnant state, thyroid-stimulating hormone (TSH) receptor (TSHR) antibodies (TRAbs) are the pathogenetic hallmark of Graves’ disease. TRAbs are heterogeneous for molecular and functional properties and are subdivided into activating (TSAbs), blocking (TBAbs), or neutral (N-TRAbs) depending on their effect on TSHR. The typical clinical features of Graves’ disease (goiter, hyperthyroidism, ophthalmopathy, dermopathy) occur when TSAbs predominate. Graves’ disease shows some peculiarities in pregnancy. The TRAbs disturb the maternal as well as the fetal thyroid function given their ability to cross the placental barrier. The pregnancy-related immunosuppression reduces the levels of TRAbs in most cases although they persist in women with active disease as well as in women who received definitive therapy (radioiodine or surgery) before pregnancy. Changes of functional properties from stimulating to blocking the TSHR could occur during gestation. Drug therapy is the treatment of choice for hyperthyroidism during gestation. Antithyroid drugs also cross the placenta and therefore decrease both the maternal and the fetal thyroid hormone production. The management of Graves’ disease in pregnancy should be aimed at maintaining euthyroidism in the mother as well as in the fetus. Maternal and fetal thyroid dysfunction (hyperthyroidism as well as hypothyroidism) are in fact associated with several morbidities. Monitoring of the maternal thyroid function, TRAbs measurement, and fetal surveillance are the mainstay for the management of Graves’ disease in pregnancy. This review summarizes the biochemical, immunological, and therapeutic aspects of Graves’ disease in pregnancy focusing on the role of the TRAbs in maternal and fetal

  7. Thyroid-Stimulating Hormone Receptor Antibodies in Pregnancy: Clinical Relevance

    Directory of Open Access Journals (Sweden)

    Ines Bucci

    2017-06-01

    Full Text Available Graves’ disease is the most common cause of thyrotoxicosis in women of childbearing age. Approximately 1% of pregnant women been treated before, or are being treated during pregnancy for Graves’ hyperthyroidism. In pregnancy, as in not pregnant state, thyroid-stimulating hormone (TSH receptor (TSHR antibodies (TRAbs are the pathogenetic hallmark of Graves’ disease. TRAbs are heterogeneous for molecular and functional properties and are subdivided into activating (TSAbs, blocking (TBAbs, or neutral (N-TRAbs depending on their effect on TSHR. The typical clinical features of Graves’ disease (goiter, hyperthyroidism, ophthalmopathy, dermopathy occur when TSAbs predominate. Graves’ disease shows some peculiarities in pregnancy. The TRAbs disturb the maternal as well as the fetal thyroid function given their ability to cross the placental barrier. The pregnancy-related immunosuppression reduces the levels of TRAbs in most cases although they persist in women with active disease as well as in women who received definitive therapy (radioiodine or surgery before pregnancy. Changes of functional properties from stimulating to blocking the TSHR could occur during gestation. Drug therapy is the treatment of choice for hyperthyroidism during gestation. Antithyroid drugs also cross the placenta and therefore decrease both the maternal and the fetal thyroid hormone production. The management of Graves’ disease in pregnancy should be aimed at maintaining euthyroidism in the mother as well as in the fetus. Maternal and fetal thyroid dysfunction (hyperthyroidism as well as hypothyroidism are in fact associated with several morbidities. Monitoring of the maternal thyroid function, TRAbs measurement, and fetal surveillance are the mainstay for the management of Graves’ disease in pregnancy. This review summarizes the biochemical, immunological, and therapeutic aspects of Graves’ disease in pregnancy focusing on the role of the TRAbs in maternal and

  8. Graves' disease: an analysis of thyroid hormone levels and hyperthyroid signs and symptoms.

    Science.gov (United States)

    Trzepacz, P T; Klein, I; Roberts, M; Greenhouse, J; Levey, G S

    1989-11-01

    Assessment of disease severity for patients with hyperthyroidism involves clinical evaluation and laboratory testing. To determine if there is a correlation between symptoms and thyroid function test results, we prospectively studied hyperthyroid patients using a standardized symptom rating scale and serum thyroid function parameters. We examined 25 patients with untreated, newly diagnosed Graves' disease using the Hyperthyroid Symptom Scale (HSS) and serum levels of thyroxine (T4), triiodothyronine (T3) relative insulin area (RIA), and estimates of free thyroxine index (FTI). In addition, we compared thyroid hormone levels with standard measures of depression and anxiety in these patients. When regression analyses controlling for age were performed, none of these symptom ratings were associated with FTI or T3 RIA. The HSS was correlated with goiter size and anxiety ratings and was inversely correlated with age. The present study suggests that there is no relationship between the clinical assessment of disease severity and serum levels of thyroid hormone in untreated Graves' disease.

  9. Developmental Thyroid Hormone Disruption: Prevalence, Environmental Contaminants and Neurodevelopmental Consequences

    Science.gov (United States)

    Thyroid hormones (TH) are critical for growth and development and particularly brain development. There are numerous environmental agents that lead to marginal reductions of circulating TH. Although it is clear that severe developmental hypothyroidism is profoundly detrimental to...

  10. Thyroid hormone levels in the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex.

    OpenAIRE

    Tang, W W; Kaptein, E M

    1989-01-01

    Hypothalamic-pituitary dysfunction and thyroid gland cytomegalovirus inclusions have been described in patients with the acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC). We evaluated 80 patients with AIDS or ARC for the frequency of hypothalamic-pituitary or thyroid gland failure and altered serum thyroid hormone levels due to nonthyroidal disorders. One patient had subclinical hypothyroidism. Of these patients, 60% had low free triiodothyronine (T3) index values and ...

  11. Utilizing mass spectrometry imaging to map the thyroid hormones triiodothyronine and thyroxine in Xenopus tropicalis tadpoles.

    Science.gov (United States)

    Goto-Inoue, Naoko; Sato, Tomohiko; Morisasa, Mizuki; Kashiwagi, Akihiko; Kashiwagi, Keiko; Sugiura, Yuki; Sugiyama, Eiji; Suematsu, Makoto; Mori, Tsukasa

    2018-02-01

    Thyroid hormones are not only responsible for thermogenesis and energy metabolism in animals, but also have an important role in cell differentiation and development. Amphibian metamorphosis provides an excellent model for studying the remodeling of the body. This metamorphic organ remodeling is induced by thyroid hormones, and a larval body is thus converted into an adult one. The matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS) imaging technology is expected to be a suitable tool for investigating small bioreactive molecules. The present study describes the distribution of the thyroid hormones, i.e., triiodothyronine (T3) and thyroxine (T4) and their inactive form reverse T3 (rT3) in Xenopus tropicalis tadpoles using two different types of imaging techniques, MS/MS and Fourier transform (FT)-MS imaging. As a result of MS/MS imaging, we demonstrated that T3 was mainly distributed in the gills. T4 was faintly localized in the eyes, inner gills, and intestine during metamorphosis. The intensity of T3 in the gills and the intensity of T4 in the body fluids were increased during metamorphosis. Moreover, the localization of the inactive form rT3 was demonstrated to be separate from T3, namely in the intestine and muscles. In addition, FT-MS imaging could utilize simultaneous imaging including thyroid hormone. This is the first report to demonstrate the molecular distribution of thyroid hormones themselves and to discriminate T3, T4, and rT3 in animal tissues.

  12. Thyroid Stimulating Hormone values from cord blood in neonates ...

    African Journals Online (AJOL)

    Objectives: To determine thyroid stimulating hormone (TSH) levels from cord blood in neonates and to establish the practice for possible application of congenital hypothyroidism screening in Ethiopia. Methods: TSH was measured from cord blood of 1207 consecutive new-borns in the maternal wards of St. Paul, Ghandi ...

  13. Noncanonical thyroid hormone signaling mediates cardiometabolic effects in vivo

    DEFF Research Database (Denmark)

    Hönes, G. Sebastian; Rakov, Helena; Logan, John

    2017-01-01

    Thyroid hormone (TH) and TH receptors (TRs) α and β act by binding to TH response elements (TREs) in regulatory regions of target genes. This nuclear signaling is established as the canonical or type 1 pathway for TH action. Nevertheless, TRs also rapidly activate intracellular second-messenger s...

  14. Effect of thyroid hormone on the protein turnover rate of mouse pancreas

    International Nuclear Information System (INIS)

    He Xinjun; Zhou Hui; Wang Shizhen; Zhou Zhonming; Li Liangxue; Wei Huaiwei; Sun Xiaomiao; Wang Yanli

    1986-01-01

    The effects of thyroid hormone on the protein turnover of pancreas in mice were studied using labelled amino acid incorporation, double isotopic and labelled protein decay methods. After injection of L-thyroxine (100 μ g/mouse) for 5 days, the amino acid incorporation into pancreatic proteins of mice was profoundly decreased, the ratio of 3 H/ 14 C in labelled proteins and the fractional turnover rate of pancreatic proteins were also decreased, the protein half-lives being consequently prolonged. These findings suggest that large doses of thyroid hormone may reduce the trunover rate of pancreatic proteins, by inhibiting not only the synthesis but also the degradation

  15. Thyroid Hormones and Thyroid Function status in each clinical phase of Korean Hemorrhagic Fever

    International Nuclear Information System (INIS)

    Shin, Young Tae; Jeon, Byung Sook; Yoon, Sung Yeul; Lee, Houn Young; Kim, Sam Yong; Ro, Heung Kyu

    1983-01-01

    Fifteen cases of Korean hemorrhagic fever who were admitted Chungnam National University Hospital from October 1981 to December 1981 were analysed on the evaluation of metabolic changes of the thyroid hormones, and thyroid function status in each clinical phase. 1) Serum T 3 , T 4 concentration, FT 4 I and T 4 /TBG ratio were significantly lower (p 4 , TSH and TBG concentration were within normal range in all phase of KHF. Thus in Korean hemorrhagic fever, euthyroidism is probably maintained by normal or elevated serum FT 4 . 2) T 4 /T 3 and rT 3 /T 3 ratio (p 4 to T 3 in oliguric and early diuretic phase.

  16. Nuclear Import and Export of the Thyroid Hormone Receptor.

    Science.gov (United States)

    Zhang, Jibo; Roggero, Vincent R; Allison, Lizabeth A

    2018-01-01

    The thyroid hormone receptors, TRα1 and TRβ1, are members of the nuclear receptor superfamily that forms one of the most abundant classes of transcription factors in multicellular organisms. Although primarily localized to the nucleus, TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm. The fine balance between nuclear import and export of TRs has emerged as a critical control point for modulating thyroid hormone-responsive gene expression. Mutagenesis studies have defined two nuclear localization signal (NLS) motifs that direct nuclear import of TRα1: NLS-1 in the hinge domain and NLS-2 in the N-terminal A/B domain. Three nuclear export signal (NES) motifs reside in the ligand-binding domain. A combined approach of shRNA-mediated knockdown and coimmunoprecipitation assays revealed that nuclear entry of TRα1 is facilitated by importin 7, likely through interactions with NLS-2, and importin β1 and the adapter importin α1 interacting with both NLS-1 and NLS-2. Interestingly, TRβ1 lacks NLS-2 and nuclear import depends solely on the importin α1/β1 heterodimer. Heterokaryon and fluorescence recovery after photobleaching shuttling assays identified multiple exportins that play a role in nuclear export of TRα1, including CRM1 (exportin 1), and exportins 4, 5, and 7. Even single amino acid changes in TRs dramatically alter their intracellular distribution patterns. We conclude that mutations within NLS and NES motifs affect nuclear shuttling activity, and propose that TR mislocalization contributes to the development of some types of cancer and Resistance to Thyroid Hormone syndrome. © 2018 Elsevier Inc. All rights reserved.

  17. Scintigraphy in benign thyroid disorders

    International Nuclear Information System (INIS)

    Mahlstedt, J.

    2004-01-01

    For diagnosis, therapy and prognosis of benign thyroidal disorders thyroidal scintigraphy has to be seen in full strength in relation to thyroid hormone metabolism and regulation. Thyroidal iodine avidity can easily be assessed by TcTU ( 99m Tc-thyroid-up-take 20 min p.inj.), as the well known standard measure for the service of goiter patients. TcTU and TSH show concordance, i.e. direct correlation, when thyroid regulation is intact, however there is no correlation, i.e. discordance, in disorders such as destruction, autonomy oder immunogenic stimulation. The strategy to evaluate concordance/discordance of TcTU and TSH in outpatient routine work (''one stop shop'') is demonstrated in a variety of clinical situations being not always conform to current guide lines and recommendations. (orig.)

  18. Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

    Science.gov (United States)

    Alvarez-Crespo, Mayte; Csikasz, Robert I.; Martínez-Sánchez, Noelia; Diéguez, Carlos; Cannon, Barbara; Nedergaard, Jan; López, Miguel

    2016-01-01

    Objective Classically, metabolic effects of thyroid hormones (THs) have been considered to be peripherally mediated, i.e. different tissues in the body respond directly to thyroid hormones with an increased metabolism. An alternative view is that the metabolic effects are centrally regulated. We have examined here the degree to which prolonged, centrally infused triiodothyronine (T3) could in itself induce total body metabolic effects and the degree to which brown adipose tissue (BAT) thermogenesis was essential for such effects, by examining uncoupling protein 1 (UCP1) KO mice. Methods Wildtype and UPC1 KO mice were centrally-treated with T3 by using minipumps. Metabolic measurements were analyzed by indirect calorimetry and expression analysis by RT-PCR or western blot. BAT morphology and histology were studied by immunohistochemistry. Results We found that central T3-treatment led to reduced levels of hypothalamic AMP-activated protein kinase (AMPK) and elevated body temperature (0.7 °C). UCP1 was essential for the T3-induced increased rate of energy expenditure, which was only observable at thermoneutrality and notably only during the active phase, for the increased body weight loss, for the increased hypothalamic levels of neuropeptide Y (NPY) and agouti-related peptide (AgRP) and for the increased food intake induced by central T3-treatment. Prolonged central T3-treatment also led to recruitment of BAT and britening/beiging (“browning”) of inguinal white adipose tissue (iWAT). Conclusions We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents. PMID:27069867

  19. Increased insulin sensitivity in intrauterine growth retarded newborns--do thyroid hormones play a role?

    Science.gov (United States)

    Setia, Sajita; Sridhar, M G; Koner, B C; Bobby, Zachariah; Bhat, Vishnu; Chaturvedula, Lata

    2007-02-01

    Thyroid hormones are necessary for normal brain development. We studied thyroid hormone profile and insulin sensitivity in intrauterine growth retarded (IUGR) newborns to find correlation between insulin sensitivity and thyroid status in IUGR newborns. Fifty IUGR and fifty healthy control infants were studied at birth. Cord blood was collected for determination of T(3), T(4), TSH, glucose and insulin levels. IUGR newborns had significantly lower insulin, mean+/-S.D., 5.25+/-2.81 vs. 11.02+/-1.85microU/ml, but significantly higher insulin sensitivity measured as glucose to insulin ratio (G/I), 9.80+/-2.91 vs. 6.93+/-1.08 compared to healthy newborns. TSH was also significantly higher 6.0+/-2.70 vs. 2.99+/-1.05microU/ml with significantly lower T(4), 8.65+/-1.95 vs. 9.77+/-2.18microg/dl, but similar T(3) levels, 100.8+/-24.36 vs. 101.45+/-23.45ng/dl. On stepwise linear regression analysis in IUGR infants, insulin sensitivity was found to have a significant negative association with T(4) and significant positive association with TSH. Thyroid hormones may play a role in increased insulin sensitivity at birth in IUGR.

  20. Analysis of thyroid hormones in gland and serum using liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Thyroid hormones (THs), which are critical for growth and development in all vertebrates, can be impacted through chemical perturbation of the hypothalamic-pituitary-thyroid (HPT)-axis. Amphibian and mammalian models are being used to address this research priority within US EPA...

  1. Chemical Hybridization of Glucagon and Thyroid Hormone Optimizes Therapeutic Impact for Metabolic Disease

    DEFF Research Database (Denmark)

    Finan, Brian; Clemmensen, Christoffer; Zhu, Zhimeng

    2016-01-01

    Glucagon and thyroid hormone (T3) exhibit therapeutic potential for metabolic disease but also exhibit undesired effects. We achieved synergistic effects of these two hormones and mitigation of their adverse effects by engineering chemical conjugates enabling delivery of both activities within on...

  2. Nitric oxide and thyroid hormone receptor alpha 1 contribute to ovarian follicular development in immature hyper- and hypo-thyroid rats.

    Science.gov (United States)

    Zheng, Kaizhi; Sulieman, Fedail Jaafar; Li, Junrong; Wei, Quanwei; Xu, Mulin; Shi, Fangxiong

    2015-03-01

    Thyroid dysfunction can cause ovarian cycle and ovulatory disturbances, however, the molecular link(s) between these two disorders remains largely unknown. In the current study, we examined the roles of nitric oxide synthase (NOS) and thyroid hormone receptor alpha 1 (TRα1) in these disorders using immature hyper-thyroid (hyper-T) and hypo-thyroid (hypo-T) rats. In comparison to controls, hyper-T rats had higher serum concentrations of triiodothyronine (T3) and thyroxine (T4), whereas hypo-T rats had lower serum T3 and T4. Serum estradiol (E2) level was decreased in both hyper-T and hypo-T animals and serum E2 in hyper-T rats were lower than in hypo-T rats. We found that neuronal NOS (nNOS) and TRα1 were present in oocytes, granulosa cells and theca cells of all examined rat groups. Ovarian nitric oxide (NO) content and the constitutive NOS (cNOS) activity in hyper-T rats were significantly decreased compared with control or hypo-T rats. Moreover, the number of large antral follicles was reduced in hyper-T rats, and number of primordial follicles was decreased in hypo-T rats compared with control rats. In conclusion, we observed an association between thyroid hormone and NO signaling pathways during the process of ovarian follicular development in immature rats. In hyperthyroidism, thyroid hormones induced an estrogen deficiency that inhibited the function of nNOS, resulting in the inhibition of NO synthesis and suppressed development of large antral follicles, while in hypothyroidism only development of primordial follicles was inhibited. Copyright © 2014 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  3. Analysis and functional characterization of sequence variations in ligand binding domain of thyroid hormone receptors in autism spectrum disorder (ASD) patients.

    Science.gov (United States)

    Kalikiri, Mahesh Kumar; Mamidala, Madhu Poornima; Rao, Ananth N; Rajesh, Vidya

    2017-12-01

    Autism spectrum disorder (ASD) is a neuro developmental disorder, reported to be on a rise in the past two decades. Thyroid hormone-T3 plays an important role in early embryonic and central nervous system development. T3 mediates its function by binding to thyroid hormone receptors, TRα and TRβ. Alterations in T3 levels and thyroid receptor mutations have been earlier implicated in neuropsychiatric disorders and have been linked to environmental toxins. Limited reports from earlier studies have shown the effectiveness of T3 treatment with promising results in children with ASD and that the thyroid hormone levels in these children was also normal. This necessitates the need to explore the genetic variations in the components of the thyroid hormone pathway in ASD children. To achieve this objective, we performed genetic analysis of ligand binding domain of THRA and THRB receptor genes in 30 ASD subjects and in age matched controls from India. Our study for the first time reports novel single nucleotide polymorphisms in the THRA and THRB receptor genes of ASD individuals. Autism Res 2017, 10: 1919-1928. ©2017 International Society for Autism Research, Wiley Periodicals, Inc. Thyroid hormone (T3) and thyroid receptors (TRα and TRβ) are the major components of the thyroid hormone pathway. The link between thyroid pathway and neuronal development is proven in clinical medicine. Since the thyroid hormone levels in Autistic children are normal, variations in their receptors needs to be explored. To achieve this objective, changes in THRA and THRB receptor genes was studied in 30 ASD and normal children from India. The impact of some of these mutations on receptor function was also studied. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

  4. Increased Procurement of Thoracic Donor Organs After Thyroid Hormone Therapy.

    Science.gov (United States)

    Novitzky, Dimitri; Mi, Zhibao; Collins, Joseph F; Cooper, David K C

    2015-01-01

    Hormonal therapy to the brain-dead organ donor can include thyroid hormone (triiodothyronine [T3] or levothyroxine [T4]), antidiuretic hormone, corticosteroids, or insulin. There has been a controversy on whether thyroid hormone enables more organs to be procured. Data on 63,593 donors of hearts and lungs (2000-2009) were retrospectively reviewed. Documentation on T3/T4 was available in all donors (study 1), and in 40,124 details of all 4 hormones were recorded (study 2). In this cohort, group A (23,022) received T3/T4 and group B (17,102) no T3/T4. Univariate analyses and multiple regressions were performed. Posttransplant graft and recipient survival at 1 and 12 months were compared. In study 1, 30,962 donors received T3/T4, with 36.59% providing a heart and 20.05% providing 1 or both lungs. Of the 32,631 donors who did not receive T3/T4, only 29.62% provided a heart and 14.61% provided lungs, an increase of 6.97% hearts and 5.44% lungs from T3/T4-treated donors (both P donor was associated with either improved posttransplant graft and recipient survival or no difference in survival. T3/T4 therapy results in more transplantable hearts and lungs, with no detriment to posttransplant graft or recipient survival. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Study protocol; Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism - a randomised placebo controlled Trial (TRUST)

    NARCIS (Netherlands)

    Stott, D.J.; Gussekloo, J.; Kearney, P.M.; Rodondi, N.; Westendorp, R.G.; Mooijaart, S.; Kean, S.; Quinn, T.J.; Sattar, N.; Hendry, K.; Puy, R. Du; Elzen, W.P. den; Poortvliet, R.K.; Smit, J.W.A.; Jukema, J.W.; Dekkers, O.M.; Blum, M.; Collet, T.H.; McCarthy, V.; Hurley, C.; Byrne, S.; Browne, J.; Watt, T.; Bauer, D.; Ford, I.

    2017-01-01

    BACKGROUND: Subclinical hypothyroidism (SCH) is a common condition in elderly people, defined as elevated serum thyroid-stimulating hormone (TSH) with normal circulating free thyroxine (fT4). Evidence is lacking about the effect of thyroid hormone treatment. We describe the protocol of a large

  6. Selenium deficiency inhibits the conversion of thyroidal thyroxine (T4) to triiodothyronine (T3) in chicken thyroids.

    Science.gov (United States)

    Lin, Shi-lei; Wang, Cong-wu; Tan, Si-ran; Liang, Yang; Yao, Hai-dong; Zhang, Zi-wei; Xu, Shi-wen

    2014-12-01

    Selenium (Se) influences the metabolism of thyroid hormones in mammals. However, the role of Se deficiency in the regulation of thyroid hormones in chickens is not well known. In the present study, we examined the levels of thyroidal triiodothyronine (T3), thyroidal thyroxine (T4), free triiodothyronine, free thyroxine (FT4), and thyroid-stimulating hormone in the serum and the mRNA expression levels of 25 selenoproteins in chicken thyroids. Then, principal component analysis (PCA) was performed to analyze the relationships between the selenoproteins. The results indicated that Se deficiency influenced the conversion of T4 to T3 and induced the accumulation of T4 and FT4. In addition, the mRNA expression levels of the selenoproteins were generally decreased by Se deficiency. The PCA showed that eight selenoproteins (deiodinase 1 (Dio1), Dio2, Dio3, thioredoxin reductase 2 (Txnrd2), selenoprotein i (Seli), selenoprotein u (Selu), glutathione peroxidase 1 (Gpx1), and Gpx2) have similar trends, which indicated that they may play similar roles in the metabolism of thyroid hormones. The results showed that Se deficiency inhibited the conversion of T4 to T3 and decreased the levels of the crucial metabolic enzymes of the thyroid hormones, Dio1, Dio2, and Dio3, in chickens. In addition, the decreased selenoproteins (Dio1, Dio2, Dio3, Txnrd2, Seli, Selu, Gpx1, and Gpx2) induced by Se deficiency may indirectly limit the conversion of T4 to T3 in chicken thyroids. The information presented in this study is helpful to understand the role of Se in the thyroid function of chickens.

  7. The evaluation of CLIA, RIA and MSP-ELISA for measurement of thyroid hormones

    International Nuclear Information System (INIS)

    Jing Hua; Li Dan; Chen Yiguang; Zhou Huiqin; Xu Liyan

    2005-01-01

    To compare the characteristics of chemiluminescent immunoassay (CLIA), RIA and magnetic solid phase enzyme-linked immnosorbent assay (MSP-ELISA) in measuring thyroid hormones, TT 3 , TT 4 , FT 3 , FT 4 and TSH were tested in 40 samples of human serum and in standard samples of thyroid hormones by CLIA, RIA and MSP-ELISA respectively. The linearity, relativiy, precision, recovery of these three met hods were compared. The result showed that there were no statistical differences between CLIA, RIA and MSP-ELISA in linearity and relativity. CLIA was better than RIA and MSP-ELISA in precision and accuracy. (authors)

  8. Histological structure and hormonal profile of pituitary and thyroid ...

    African Journals Online (AJOL)

    This study aims to evaluate the effects of castration and iodine supplementaion on the histological structure of pituitary and thyroid glands and their related hormones in NZW male rabbits. Animals were randomly divided into two groups. The first group was supplemented with iodine as potassium iodide at a level of 400 ppm ...

  9. Thyroid Hormone and Blood Metabolites Concentration of Gilts Superovulated Prior to Mating

    Directory of Open Access Journals (Sweden)

    RA Mege

    2009-05-01

    Full Text Available An experiment was conducted to study injection of pregnant mare serum gonadotrophin (PMSG and human chorionic gonadotrophin (hCG as superovulation agent in gilts to improve thyroid hormone and blood metabolites concentraton. In this experiment, 48 gilts were assigned into four groups of twelve gilts injected with PMSG dan hCG dose levels of 0, 600, 1200 and 1800 IU/gilt. Injections were conducted three days before estrus. During gestation, gilts were placed in colony pigpen. On days 15, 35, and 70 of gestation blood collected to determine triiodothyronine, tetraiodothyronine, tryglicerides, glucose, protein and bood nitrogen urea concentration. The resuts showed that superovulation dose levels of 600 to 1200 IU/gilt increased concentration of thyroid hormone (triiodothyronine and tetraiodothyronine/thyroxin and blood metabolite (triglycerides, glucose, and protein, but decreased blood urea nitrogen in gestation ages 15, 35, and 70 days. It is concluded that superovulation with dose of 600 to 1200 IU can improve of gilts metabolite hormone and blood metabolites. (Animal Production 11(2: 88-95 (2009Key Words: gilts, superovulation, metabolite hormone, blood metabolites

  10. Short-chain chlorinated paraffins (SCCPs) induced thyroid disruption by enhancement of hepatic thyroid hormone influx and degradation in male Sprague Dawley rats.

    Science.gov (United States)

    Gong, Yufeng; Zhang, Haijun; Geng, Ningbo; Xing, Liguo; Fan, Jingfeng; Luo, Yun; Song, Xiaoyao; Ren, Xiaoqian; Wang, Feidi; Chen, Jiping

    2018-06-01

    Short-chain chlorinated paraffins (SCCPs) are known to disturb thyroid hormone (TH) homeostasis in rodents. However, the mechanism remains to be fully characterized. In this study, male Sprague Dawley rats received SCCPs (0, 1, 10, or 100mg/kg/day) via gavage once a day for consecutive 28days. Plasma and hepatic TH concentrations, thyrocyte structure, as well as thyroid and hepatic mRNA and protein levels of genes associated with TH homeostasis were examined. Moreover, we performed molecular docking to predict interactions between constitutive androstane receptor (CAR), a key regulator in xenobiotic-induced TH metabolism, with different SCCP molecules. Exposure to SCCPs significantly decreased the circulating free thyroxine (T 4 ) and triiodothyronine (T 3 ) levels, but increased thyroid-stimulating hormone (TSH) levels by a feedback mechanism. Decreased hepatic T 4 and increased hepatic T 3 levels were also seen after 100mg/kg/day SCCPs exposure. SCCPs didn't show any significant effects on the expression of thyroid TH synthesis genes or thyrocyte structure. However, stimulation effects were observed for mRNA and protein levels of hepatic uridine diphosphoglucuronosyl transferase (UGT) 1A1 and organic anion transporter 2, suggesting an accelerated TH metabolism in rat liver. The increased cytochrome P450 2B1 but not 1A1 mRNA and protein levels indicated that the CAR signaling was activated by SCCPs exposure. According to docking analysis, SCCPs form hydrophobic interactions with CAR and the binding affinity shows dependency on chlorine content. Overall, our data showed that CAR implicated enhancement of hepatic TH influx and degradation could be the main cause for SCCPs induced TH deficiency in male rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Effect of race, gender and age on thyroid and thyroid stimulating hormone levels in north west frontier province, Pakistan

    International Nuclear Information System (INIS)

    Ahmed, Z.; Khan, M.A.; Haq, A.U.

    2009-01-01

    Thyroid is one of the ductless endocrine gland, which is located immediately below the larynx on either side of and anterior to the trachea. The principal hormones of thyroid gland are thyroxine (T4) and triiodothyronine (T3). The current study was carried out to investigate the impact of race, gender and area on the levels of Thyroxine (T4), Triiodothyronine (T3) and Thyroid Stimulating Hormone (TSH) in normal healthy individuals. Methods: Serum levels of T4, T3 and TSH in 498 normal healthy individuals belonging to different districts of North West Frontier Province, Pakistan, were examined. Serum T4 and T3 were analysed by Radio Immuno Assay (RIA) method whereas TSH was estimated by Immunoradiometric assay (IRMA) method. Results: Levels of T4, T3 and TSH ranged from 53 to 167 m mu mol/L and 0.3-4.8 mu mol/L respectively. The levels of these hormones show significant change from the reference values that are used in clinical laboratories as well as in Institute of Rauclear Medicine (IRNUM), Peshawar, Pakistan. Conclusion: It is concluded that the age, gender, race and area, all have an appreciable effect on the levels T4, T3 and TSH. (author)

  12. Higher Thyroid-Stimulating Hormone, Triiodothyronine and Thyroxine Values Are Associated with Better Outcome in Acute Liver Failure.

    Science.gov (United States)

    Anastasiou, Olympia; Sydor, Svenja; Sowa, Jan-Peter; Manka, Paul; Katsounas, Antonios; Syn, Wing-Kin; Führer, Dagmar; Gieseler, Robert K; Bechmann, Lars P; Gerken, Guido; Moeller, Lars C; Canbay, Ali

    2015-01-01

    Changes in thyroid hormone levels, mostly as non-thyroidal illness syndrome (NTIS), have been described in many diseases. However, the relationship between acute liver failure (ALF) and thyroid hormone levels has not yet been clarified. The present study evaluates potential correlations of select thyroid functional parameters with ALF. 84 consecutively recruited ALF patients were grouped according to the outcome of ALF (spontaneous recovery: SR; transplantation or death: NSR). TSH, free thyroxine (fT4), free triiodothyronine (fT3), T4, and T3 were determined. More than 50% of patients with ALF presented with abnormal thyroid parameters. These patients had greater risk for an adverse outcome than euthyroid patients. SR patients had significantly higher TSH, T4, and T3 concentrations than NSR patients. Albumin concentrations were significantly higher in SR than in NSR. In vitro T3 treatment was not able to rescue primary human hepatocytes from acetaminophen induced changes in mRNA expression. In patients with ALF, TSH and total thyroid hormone levels differed significantly between SR patients and NSR patients. This might be related to diminished liver-derived transport proteins, such as albumin, in more severe forms of ALF. Thyroid parameters may serve as additional indicators of ALF severity.

  13. D2-Thr92Ala, thyroid hormone levels and biochemical hypothyroidism in preeclampsia.

    Science.gov (United States)

    Procopciuc, Lucia Maria; Caracostea, Gabriela; Hazi, Georgeta; Nemeti, Georgiana; Stamatian, Florin

    2017-02-01

    To identify if there is a relationship between the deiodinase D2-Thr92Ala genetic variant, thyroid hormone levels and biochemical hypothyroidism in preeclampsia. We genotyped 125 women with preeclampsia and 131 normal pregnant women using PCR-RFLP. Serum thyroid hormone levels were determined using ELISA. Our study showed higher TSH and FT4 levels and lower FT3 levels in women with preeclampsia compared to normal pregnant women, with statistical significance for women with mild and severe preeclampsia. The risk to develop pregnancy-induced hypertension (PIH), mild or severe preeclampsia was increased in carriers of at least one D2-Ala92 allele. TSH and FT4 levels were significantly higher and FT3 levels were significantly lower in preeclamptic women with severe preeclampsia if they carried the D2-Ala92 allele compared to non-carriers. Pregnant women with PIH and mild preeclampsia, carriers of at least one D2-Ala92 allele, delivered at lower gestational age neonates with a lower birth weight compared to non-carriers, but the results were statistically significant only in severe preeclampsia. The D2-Thr92Ala genetic variant is associated with the severity and the obstetric outcome of preeclampsia, and it also influences thyroid hormone levels. The study demonstrates non-thyroidal biochemical hypothyroidism - as a result of deiodination effects due to D2 genotypes.

  14. Gestational urinary bisphenol A and maternal and newborn thyroid hormone concentrations: The HOME Study

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Megan E., E-mail: megan_romano@brown.edu [Department of Epidemiology, Brown University School of Public Health, Providence, RI (United States); Webster, Glenys M. [Child and Family Research Institute, BC Children' s and Women' s Hospital and Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia (Canada); Vuong, Ann M. [Division of Epidemiology and Biostatistics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Thomas Zoeller, R. [Department of Biology, University of Massachusetts, Amherst, MA (United States); Chen, Aimin [Division of Epidemiology and Biostatistics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Hoofnagle, Andrew N. [Department of Laboratory Medicine, University of Washington, Seattle, WA (United States); Calafat, Antonia M. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Karagas, Margaret R. [Children' s Environmental Health and Disease Prevention Research Center and Department of Community and Family Medicine, Geisel School of Medicine at Dartmouth, Hanover, NH (United States); Yolton, Kimberly [Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Lanphear, Bruce P. [Child and Family Research Institute, BC Children' s and Women' s Hospital and Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia (Canada); Braun, Joseph M. [Department of Epidemiology, Brown University School of Public Health, Providence, RI (United States)

    2015-04-15

    Bisphenol A (BPA), an endocrine disruptor used in consumer products, may perturb thyroid function. Prenatal BPA exposure may have sex-specific effects on thyroid hormones (THs). Our objectives were to investigate whether maternal urinary BPA concentrations during pregnancy were associated with THs in maternal or cord serum, and whether these associations differed by newborn sex or maternal iodine status. We measured urinary BPA concentrations at 16 and 26 weeks gestation among pregnant women in the HOME Study (2003–2006, Cincinnati, Ohio). Thyroid stimulating hormone (TSH) and free and total thyroxine (T{sub 4}) and triiodothyronine (T{sub 3}) were measured in maternal serum at 16 weeks (n=181) and cord serum at delivery (n=249). Associations between BPA concentrations and maternal or cord serum TH levels were estimated by multivariable linear regression. Mean maternal urinary BPA was not associated with cord THs in all newborns, but a 10-fold increase in mean BPA was associated with lower cord TSH in girls (percent change=−36.0%; 95% confidence interval (CI): −58.4, −1.7%), but not boys (7.8%; 95% CI: −28.5, 62.7%; p-for-effect modification=0.09). We observed no significant associations between 16-week BPA and THs in maternal or cord serum, but 26-week maternal BPA was inversely associated with TSH in girls (−42.9%; 95% CI: −59.9, −18.5%), but not boys (7.6%; 95% CI: −17.3, 40.2%; p-for-effect modification=0.005) at birth. The inverse BPA–TSH relation among girls was stronger, but less precise, among iodine deficient versus sufficient mothers. Prenatal BPA exposure may reduce TSH among newborn girls, particularly when exposure occurs later in gestation. - Highlights: • Examined associations of BPA with thyroid hormones in pregnant women and newborns. • Assessed effect modification of BPA–thyroid hormone associations by newborn sex. • Greater BPA related to decreased thyroid stimulating hormone in girls' cord serum. • Results may

  15. Gestational urinary bisphenol A and maternal and newborn thyroid hormone concentrations: The HOME Study

    International Nuclear Information System (INIS)

    Romano, Megan E.; Webster, Glenys M.; Vuong, Ann M.; Thomas Zoeller, R.; Chen, Aimin; Hoofnagle, Andrew N.; Calafat, Antonia M.; Karagas, Margaret R.; Yolton, Kimberly; Lanphear, Bruce P.; Braun, Joseph M.

    2015-01-01

    Bisphenol A (BPA), an endocrine disruptor used in consumer products, may perturb thyroid function. Prenatal BPA exposure may have sex-specific effects on thyroid hormones (THs). Our objectives were to investigate whether maternal urinary BPA concentrations during pregnancy were associated with THs in maternal or cord serum, and whether these associations differed by newborn sex or maternal iodine status. We measured urinary BPA concentrations at 16 and 26 weeks gestation among pregnant women in the HOME Study (2003–2006, Cincinnati, Ohio). Thyroid stimulating hormone (TSH) and free and total thyroxine (T 4 ) and triiodothyronine (T 3 ) were measured in maternal serum at 16 weeks (n=181) and cord serum at delivery (n=249). Associations between BPA concentrations and maternal or cord serum TH levels were estimated by multivariable linear regression. Mean maternal urinary BPA was not associated with cord THs in all newborns, but a 10-fold increase in mean BPA was associated with lower cord TSH in girls (percent change=−36.0%; 95% confidence interval (CI): −58.4, −1.7%), but not boys (7.8%; 95% CI: −28.5, 62.7%; p-for-effect modification=0.09). We observed no significant associations between 16-week BPA and THs in maternal or cord serum, but 26-week maternal BPA was inversely associated with TSH in girls (−42.9%; 95% CI: −59.9, −18.5%), but not boys (7.6%; 95% CI: −17.3, 40.2%; p-for-effect modification=0.005) at birth. The inverse BPA–TSH relation among girls was stronger, but less precise, among iodine deficient versus sufficient mothers. Prenatal BPA exposure may reduce TSH among newborn girls, particularly when exposure occurs later in gestation. - Highlights: • Examined associations of BPA with thyroid hormones in pregnant women and newborns. • Assessed effect modification of BPA–thyroid hormone associations by newborn sex. • Greater BPA related to decreased thyroid stimulating hormone in girls' cord serum. • Results may suggest

  16. Three-compartmental analysis of effects of D-propranolol on thyroid hormone kinetics

    International Nuclear Information System (INIS)

    Van Der Heijden, J.T.M.; Krenning, E.P.; Van Toor, H.; Hennemann, G.; Docter, R.

    1988-01-01

    Tracer thyroxine (T 4 ), 3,3',5-triiodothyronine (T 3 ), and 3,3',5'-triiodothyronine (rT 3 ) kinetic studies were performed in normal T 4 substituted subjects before and during oral D-propranolol treatment to determine whether changes in thyroid hormone metabolism in a propranolol-induced low-T 3 syndrome result from inhibition of 5'-deiodination or inhibition of transport of iodothyronines into tissues. Data were analyzed according to a three-compartmental model of distribution and metabolism. No changes were observed in size of the three T 4 compartments or in fractional and mass transfer rates of T 4 from plasma to the rapidly (REP) and slowly (SEP) equilibrating pools. Serum T 3 , free T 3 , T 3 plasma pool, T 3 mass transfer rate to REP and SEP, and the T 3 pool masses were all significantly decreased during propranolol to a similar extent as the T 3 plasma production rate (PR). It is concluded that the D-propranolol-induced changes in thyroid hormone metabolism, resulting in a low-T 3 syndrome, are due to inhibition of thyroid hormone deiodination. This is in contrast to the low-T 3 syndrome during caloric deprivation, which results from inhibition of transport of iodothyronines into the liver

  17. Effects of thyroid hormone status on metabolic pathways of arachidonic acid in mice and humans: A targeted metabolomic approach.

    Science.gov (United States)

    Yao, Xuan; Sa, Rina; Ye, Cheng; Zhang, Duo; Zhang, Shengjie; Xia, Hongfeng; Wang, Yu-cheng; Jiang, Jingjing; Yin, Huiyong; Ying, Hao

    2015-01-01

    Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Differences in Brain Glucose Metabolism During Preparation for 131I Ablation in Thyroid Cancer Patients: Thyroid Hormone Withdrawal Versus Recombinant Human Thyrotropin.

    Science.gov (United States)

    Jeong, Hyeonseok S; Choi, Eun Kyoung; Song, In-Uk; Chung, Yong-An; Park, Jong-Sik; Oh, Jin Kyoung

    2017-01-01

    In preparation for 131 I ablation, temporary withdrawal of thyroid hormone is commonly used in patients with thyroid cancer after total thyroidectomy. The current study aimed to investigate brain glucose metabolism and its relationships with mood or cognitive function in these patients using 18 F-fluoro-2-deoxyglucose positron emission tomography ( 18 F-FDG-PET). A total of 40 consecutive adult patients with thyroid carcinoma who had undergone total thyroidectomy were recruited for this cross-sectional study. At the time of assessment, 20 patients were hypothyroid after two weeks of thyroid hormone withdrawal, while 20 received thyroid hormone replacement therapy and were euthyroid. All participants underwent brain 18 F-FDG-PET scans and completed mood questionnaires and cognitive tests. Multivariate spatial covariance analysis and univariate voxel-wise analysis were applied for the image data. The hypothyroid patients were more anxious and depressed than the euthyroid participants. The multivariate covariance analysis showed increases in glucose metabolism primarily in the bilateral insula and surrounding areas and concomitant decreases in the parieto-occipital regions in the hypothyroid group. The level of thyrotropin was positively associated with the individual expression of the covariance pattern. The decreased 18 F-FDG uptake in the right cuneus cluster from the univariate analysis was correlated with the increased thyrotropin level and greater depressive symptoms in the hypothyroid group. These results suggest that temporary hypothyroidism, even for a short period, may induce impairment in glucose metabolism and related affective symptoms.

  19. Serum concentration of thyroxin and thyroid stimulating hormone in children suspected of thyroid dysfunction

    International Nuclear Information System (INIS)

    Elahi, S.; Syed, Z.; Rasheed, H.; Aman, Z.; Yasmeen, R.

    2010-01-01

    This study was planned to investigate serum concentration of free thyroxin (FT/sub 4/) and thyroid stimulating hormone (TSH) as well as thyroid dysfunctions in children attending CENUM, Mayo Hospital Lahore. A total of 227 children (131 female and 96 male) were selected for this study. Their age range was 1 to 12 years (mean 7.6 +- 3.4 years). 45 (19.8%) children had goiter with significantly more frequency in female as compared to male children (28.2% V s 8.3%; p<0.05). More than 70% of the children had F/sub 4/ and TSH within their respective normal ranges (euthyroid). Thyroid dysfunctions were detected in 11.0% children (7.5% hypothyroidism; 3.5% hyperthyroidism). Only the incidence of hyperthyroidism was significantly more in goiterous children. There was no significant difference in the incidence of hyperthyroidism but hypothyroidism was significant (p<0.05) more common in female children. (author)

  20. Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails

    Directory of Open Access Journals (Sweden)

    DANILO LUSTRINO

    Full Text Available ABSTRACT The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

  1. Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails.

    Science.gov (United States)

    Lustrino, Danilo; Silva, Alba C M; Araujo, Iracema G; Tunholi, Victor M; Tunholi-Alves, Vinícius M; Castro, Rosane N; Carvalho, Denise P; Pinheiro, Jairo; Marassi, Michelle P

    2017-01-01

    The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

  2. Dependency of maximum goitrogenic response on some minimal level of thyroid hormone production

    International Nuclear Information System (INIS)

    March, B.E.; Poon, R.

    1981-01-01

    Thyroidal activity was studied in chicks given dietary thiouracil in conjunction with daily doses of thyroxine and with diets adequate and deficient in iodine. DL-thyroxine administered at doses up to 1.0 microgram per day for 10 to 12 days had no effect or slightly increased thyroid weight. Both the epithelial and colloid components of the thyroid gland were increased in response to thiouracil and to thiouracil in combination with low dosages of exogenous thyroxine. Radioiodine uptake was increased above the control with thiouracil and with thiouracil in conjunction with .5 and 1.0 microgram DL-thyroxine given daily. Birds receiving thiouracil, with and without exogenous thyroxine, showed a different pattern of radioiodine uptake and release than the control birds. Thiouracil-treated birds showed a rapid uptake of iodine following its administration, which was followed by a rapid decline immediately after peak accumulation, whereas in control birds thyroidal radioiodine concentration reached a plateau at the maximum concentration attained. The goitrogenic response to thiouracil was much greater when the diet was supplemented with iodine than when the diet was iodine-deficient. Thyroids under iodine deficiency contained greater percentages of epithelial tissue than with iodine-supplemented diets. Thyroid glands of chicks given thiouracil in an iodine-supplemented diet contained much more colloid than glands from iodine-deficient chicks with or without thiouracil. DL-thyroxine at a dosage of .5 microgram per day to chicks given thiouracil in an iodine-adequate diet increased, whereas higher dosages decreased thyroidal colloid. It is concluded that some minimal concentration of thyroid hormone is required for maximum goitrogenic response. It is not clear whether the response is entirely due to an effect on thyrotropin production or whether there is an effect of thyroid hormone on the thyroid gland itself

  3. Thyroiditis: an integrated approach.

    Science.gov (United States)

    Sweeney, Lori B; Stewart, Christopher; Gaitonde, David Y

    2014-09-15

    Thyroiditis is a general term that encompasses several clinical disorders characterized by inflammation of the thyroid gland. The most common is Hashimoto thyroiditis; patients typically present with a nontender goiter, hypothyroidism, and an elevated thyroid peroxidase antibody level. Treatment with levothyroxine ameliorates the hypothyroidism and may reduce goiter size. Postpartum thyroiditis is transient or persistent thyroid dysfunction that occurs within one year of childbirth, miscarriage, or medical abortion. Release of preformed thyroid hormone into the bloodstream may result in hyperthyroidism. This may be followed by transient or permanent hypothyroidism as a result of depletion of thyroid hormone stores and destruction of thyroid hormone-producing cells. Patients should be monitored for changes in thyroid function. Beta blockers can treat symptoms in the initial hyperthyroid phase; in the subsequent hypothyroid phase, levothyroxine should be considered in women with a serum thyroid-stimulating hormone level greater than 10 mIU per L, or in women with a thyroid-stimulating hormone level of 4 to 10 mIU per L who are symptomatic or desire fertility. Subacute thyroiditis is a transient thyrotoxic state characterized by anterior neck pain, suppressed thyroid-stimulating hormone, and low radioactive iodine uptake on thyroid scanning. Many cases of subacute thyroiditis follow an upper respiratory viral illness, which is thought to trigger an inflammatory destruction of thyroid follicles. In most cases, the thyroid gland spontaneously resumes normal thyroid hormone production after several months. Treatment with high-dose acetylsalicylic acid or nonsteroidal anti-inflammatory drugs is directed toward relief of thyroid pain.

  4. Developmental thyroid hormone insufficiency and brain development: A role for brain-derived neurotrophic factor (BDNF)?*

    Science.gov (United States)

    Thyroid hormones (TH) are essential for normal brain development. Even subclinical hypothyroidism experienced in utero can result in neuropsychological deficits in children despite normal thyroid status at birth. Neurotrophins have been implicated in a host of brain cellular func...

  5. Comparison Between the Effects of the Alcholic Extract of Mellissia Officinalis and Atorvastatin on Serum Levels of Thyroid Hormones in Hypercholesterolemic Male Rats

    Directory of Open Access Journals (Sweden)

    Ali Zarei

    2013-08-01

    Full Text Available Background: Consumption of unsaturated fats reduces the serum level of lipids and leptin. Thyroid hormones and leptin play pivotal roles in metabolism and their amounts are inter-related. This study was done to compare the effects of Mellissia officinalis extract and atorvastatin on the serum levels of thyroid hormones in hypercholesterolemia rats.Materials and Methods: Consumption of unsaturated fats reduces the serum level of lipids and leptin. Thyroid hormones and leptin play pivotal roles in metabolism and their amounts are inter-related. This study was done to compare the effects of Mellissia officinalis extract and atorvastatin on the serum levels of thyroid hormones in hypercholesterolemia rats.Results: The results showed that in experimental groups receiving the plant extract and atorvastatin, the concentration of thyroid hormones increased, whereas the amount of the thyroid-stimulating hormone showed a significant decrease (p<0.05.Conclusion: Mellissia officinalis extract decreases TSH but it increases T3 and T4. Further studies are required for applying this extract to the treatment of hyperthyroidism.

  6. Examining recombinant human TSH primed 131I therapy protocol in patients with metastatic differentiated thyroid carcinoma: comparison with the traditional thyroid hormone withdrawal protocol

    International Nuclear Information System (INIS)

    Rani, Deepa; Kaisar, Sushma; Awasare, Sushma; Kamaldeep; Abhyankar, Amit; Basu, Sandip

    2014-01-01

    Recombinant human thyroid-stimulating hormone (rhTSH)-based protocol is a promising recent development in the management of differentiated thyroid carcinoma (DTC). The objectives of this prospective study were: (1) to assess the feasibility and efficacy of the rhTSH primed 131 I therapy protocol in patients with DTC with distant metastatic disease, (2) to perform lesional dosimetry in this group of patients compared to the traditional protocol, (3) to document the practical advantages (patient symptoms and hospital stay) of the rhTSH protocol compared to the traditional thyroid hormone withdrawal protocol, (4) to document and record any adverse effect of this strategy, (5) to compare the renal function parameters, and (6) to compare the serum TSH values achieved in either of the protocols in this group of patients. The study included 37 patients with metastatic DTC having lung or skeletal metastases or both. A comparison of lesional radiation absorbed dose, hospital stay, renal function tests, and symptom profile was undertaken between the traditional thyroid hormone withdrawal protocol and rhTSH-based therapy protocol. Dosimetric calculations of metastatic lesions were performed using lesion uptake and survey meter readings for calculation of effective half-life. Non-contrast-enhanced CT was used for assessment of tumor volume. Quality of life was assessed using the European Organization for Research and Treatment of Cancer (EORTC) QOL forms. A comparison of pretreatment withdrawal thyroglobulin (TG) was done with the withdrawal TG level 3 months after treatment. The mean effective half-life of 131 I in metastatic lesions was less during the rhTSH protocol (29.49 h) compared to the thyroid hormone withdrawal protocol (35.48 h), but the difference was not statistically significant (p = 0.056). The mean 24-h % uptake of the lesions during the traditional protocol (4.84 %) was slightly higher than the 24-h % uptake during the rhTSH protocol (3.56 %), but the

  7. Correlative link ages between indices of bone metabolism and thyroid hormones in rats with periodontitis

    Directory of Open Access Journals (Sweden)

    Vitaliy Shcherba

    2017-12-01

    Full Text Available Introduction: It has been established that changes in the bone tissue of the jaw are present in all cases where there are at least small pathological inflammatory changes in the mucous membrane of the oral cavity. This suggests a significantly greater pathogenetic relationship between inflammatory changes in the mucosa and changes in the bone part of the periodontal disease. Despite a large number of studies, the molecular mechanisms of the influence of thyroid hormones on the bone metabolism have not been completely studied.  The aim of study: to clarify mechanisms of the periodontitis development in rats with thyroid dysfunction based on a comparative analysis of the correlations between the bone metabolism indices and the concentration of  thyroid stimulating hormone,  free thyroxine and free triiodothyronine. Material and methods: Experimental studies were conducted on male, nonliner, white rats of around 4 months of age.  The experimental animals were divided into the following groups: І – control animals;  ІІ – animals with periodontitis; ІІІ – animals with periodontitis combined with hyperthyroidism; IV – animals with periodontitis combined with hypothyroidism. Total calcium, ionized calcium, phosphorus, osteocalcin concentration and  activity of phosphatases were measured. Correlation analysis was performed between all the studied indices. Coefficient of linear correlation (r and its fidelity (p was calculated that was accordingly denoted in the tables (correlation matrices. The correlation coefficient was significant at p<0.05. Results: The conducted correlative analysis shows that there are different interconnections between the indices of calcium-phosphorus metabolism, bone formation and bone resorption with free triiodothyronine, free thyroxine and thyroid stimulating hormone, in case of the experimental periodontitis combined with thyroid dysfunction. In animals with modelled periodontitis combined with

  8. The immediate and late effects of thyroid hormone (triiodothyronine) on murine coagulation gene transcription

    NARCIS (Netherlands)

    Salloum-Asfar, Salam; Boelen, Anita; Reitsma, Pieter H.; van Vlijmen, Bart J. M.

    2015-01-01

    Thyroid dysfunction is associated with changes in coagulation. The aim of our study was to gain more insight into the role of thyroid hormone in coagulation control. C57Black/6J mice received a low-iodine diet and drinking water supplemented with perchlorate to suppress endogenous triiodothyronine

  9. Comparison of therapeutic efficacy and clinical parameters between recombinant human thyroid stimulating hormone and thyroid hormone withdrawal in high-dose radioiodine treatment with differentiated thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Se Hun; Na, Chang Ju; Kim, Jeong Hun; Han, Yeon Hee; KIm, Hee Kwon; Jeong, Hwan Jeong; Sohn, Myung Hee; Lim, Seok Tae [Dept. of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2015-06-15

    High-dose radioiodine treatment (HD-RIT) after injection of recombinant human thyroid stimulating hormone (rh-TSH) has become widely used. This study compared the therapeutic efficacy of HD-RIT and clinical parameters between rh-TSH supplement and thyroid hormone withdrawal (THW) after total thyroidectomy in patients with differentiated thyroid cancer. We retrospectively reviewed 266 patients (47 male and 219 female; age, 49.0 ± 10.9 years) with differentiated thyroid cancer detected from September 2011 to September 2012. Patients comprised THW (217, 81.6 %) and rh-TSH (49, 18.4 %). Inclusion criteria were: first HD-RIT; any TN stage; absence of distant metastasis. To evaluate the complete ablation of the remnant thyroid tissue or metastasis, we reviewed stimulated serum thyroglobulin (sTg), I-123 whole-body scan (RxWBS) on T4 off-state, and thyroid ultrasonography (US) or [F-18]-fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) 6–8 months after HD-RIT. We defined a complete ablation state when all three of the follow-up conditions were satisfied; <2.0 ng/ml of the sTg, I-123 RxWBS (−), and thyroid US or F-18 FDG PET/CT (−). If one of the three was positive, ablation was considered incomplete. We also compared various clinical biomarkers (body weight, body mass index, liver and kidney function) between THW and rh-TSH groups. The rates of complete ablation were 73.7 % (160/217) for the THW group and 73.5 % (36/49) for the rh-TSH group. There was no significant difference between the two groups (p = 0.970). The follow-up aspartate transaminase (p = 0.001) and alanine transaminase (p = 0.001) were significantly higher in the THW group. The renal function parameters of blood urea nitrogen (p = 0.001) and creatinine (p = 0.005) tended to increase in the THW group. The change of body weight was + Δ0.96 (±1.9) kg for the THW group and was decreased by -Δ1.39 (±1.5) kg for the rh-TSH group. The change

  10. Thyroid hormone status and health-related quality of life in the LifeLines Cohort Study

    NARCIS (Netherlands)

    Klaver, Elise I; van Loon, Hannah C M; Stienstra, Riejanne; Links, Thera P; Keers, Joost C; Kema, Ido P; Kobold, Anneke C Muller; van der Klauw, Melanie M; Wolffenbuttel, Bruce H R

    Background: Thyroid disorders are prevalent in Western society, yet many subjects experience limited symptoms at diagnosis, especially in hypothyroidism. We hypothesize that health-related quality of life (HR-QOL) is more severely impaired in subjects with more abnormal thyroid hormone function

  11. Myopathy in hyperthyroidism as a consequence of rapid reduction of thyroid hormone

    Science.gov (United States)

    Li, Qianrui; Liu, Yuping; Zhang, Qianying; Tian, Haoming; Li, Jianwei; Li, Sheyu

    2017-01-01

    Abstract Rationale: Myalgia and elevated creatine kinase (CK) are occasionally observed during the treatment of hyperthyroid patients. Relative hypothyroidism resulted from rapid thyroid hormone reduction had been promoted as a plausible cause of these myopathic changes, however rarely reported. Patient concerns: We hereby presented a 20-year-old female with Grave's disease, who developed myopathy and elevated CK during rapid correction of thyroid hormone. Diagnoses: Relative hypothyroidism-induced myopathy. Interventions: Antithyroid drug (ATD) dosage was reduced without levothyroxine replacement. Outcomes: The muscular symptoms were recovered with CK level returned to normal after adoption of the euthyroid status. Lessons: Differentiation of relative hypothyroidism from other causes of myopathy, especially with the effect of ATD, is important for clinical practice, although difficult in many cases. PMID:28746208

  12. Thyroid Hormone Availability and Action during Brain Development in Rodents.

    Science.gov (United States)

    Bárez-López, Soledad; Guadaño-Ferraz, Ana

    2017-01-01

    Thyroid hormones (THs) play an essential role in the development of all vertebrates; in particular adequate TH content is crucial for proper neurodevelopment. TH availability and action in the brain are precisely regulated by several mechanisms, including the secretion of THs by the thyroid gland, the transport of THs to the brain and neural cells, THs activation and inactivation by the metabolic enzymes deiodinases and, in the fetus, transplacental passage of maternal THs. Although these mechanisms have been extensively studied in rats, in the last decade, models of genetically modified mice have been more frequently used to understand the role of the main proteins involved in TH signaling in health and disease. Despite this, there is little knowledge about the mechanisms underlying THs availability in the mouse brain. This mini-review article gathers information from findings in rats, and the latest findings in mice regarding the ontogeny of TH action and the sources of THs to the brain, with special focus on neurodevelopmental stages. Unraveling TH economy and action in the mouse brain may help to better understand the physiology and pathophysiology of TH signaling in brain and may contribute to addressing the neurological alterations due to hypo and hyperthyroidism and TH resistance syndromes.

  13. Thyroid Hormone Availability and Action during Brain Development in Rodents

    Directory of Open Access Journals (Sweden)

    Soledad Bárez-López

    2017-08-01

    Full Text Available Thyroid hormones (THs play an essential role in the development of all vertebrates; in particular adequate TH content is crucial for proper neurodevelopment. TH availability and action in the brain are precisely regulated by several mechanisms, including the secretion of THs by the thyroid gland, the transport of THs to the brain and neural cells, THs activation and inactivation by the metabolic enzymes deiodinases and, in the fetus, transplacental passage of maternal THs. Although these mechanisms have been extensively studied in rats, in the last decade, models of genetically modified mice have been more frequently used to understand the role of the main proteins involved in TH signaling in health and disease. Despite this, there is little knowledge about the mechanisms underlying THs availability in the mouse brain. This mini-review article gathers information from findings in rats, and the latest findings in mice regarding the ontogeny of TH action and the sources of THs to the brain, with special focus on neurodevelopmental stages. Unraveling TH economy and action in the mouse brain may help to better understand the physiology and pathophysiology of TH signaling in brain and may contribute to addressing the neurological alterations due to hypo and hyperthyroidism and TH resistance syndromes.

  14. Thyroid hormone promotes remodeling of coronary resistance vessels.

    Directory of Open Access Journals (Sweden)

    Olga V Savinova

    Full Text Available Low thyroid hormone (TH function has been linked to impaired coronary blood flow, reduced density of small arterioles, and heart failure. Nonetheless, little is known about the mechanisms by which THs regulate coronary microvascular remodeling. The current study examined the initial cellular events associated with coronary remodeling induced by triiodothyronine (T3 in hypothyroid rats. Rats with established hypothyroidism, eight weeks after surgical thyroidectomy (TX, were treated with T3 for 36 or 72 hours. The early effects of T3 treatment on coronary microvasculature were examined morphometrically. Gene expression changes in the heart were assessed by quantitative PCR Array. Hypothyroidism resulted in arteriolar atrophy in the left ventricle. T3 treatment rapidly induced small arteriolar muscularization and, within 72 hours, restored arteriolar density to control levels. Total length of the capillary network was not affected by TX or T3 treatment. T3 treatment resulted in the coordinate regulation of Angiopoietin 1 and 2 expression. The response of Angiopoietins was consistent with vessel enlargement. In addition to the well known effects of THs on vasoreactivity, these results suggest that THs may affect function of small resistance arteries by phenotypic remodeling of vascular smooth muscle cells (VSMC.

  15. Thyroid hormones and mortality risk in euthyroid individuals: the Kangbuk Samsung health study.

    Science.gov (United States)

    Zhang, Yiyi; Chang, Yoosoo; Ryu, Seungho; Cho, Juhee; Lee, Won-Young; Rhee, Eun-Jung; Kwon, Min-Jung; Pastor-Barriuso, Roberto; Rampal, Sanjay; Han, Won Kon; Shin, Hocheol; Guallar, Eliseo

    2014-07-01

    Hyperthyroidism and hypothyroidism, both overt and subclinical, are associated with all-cause and cardiovascular mortality. The association between thyroid hormones and mortality in euthyroid individuals, however, is unclear. To examine the prospective association between thyroid hormones levels within normal ranges and mortality endpoints. A prospective cohort study of 212 456 middle-aged South Korean men and women who had normal thyroid hormone levels and no history of thyroid disease at baseline from January 1, 2002 to December 31, 2009. Free T4 (FT4), free T3 (FT3), and TSH levels were measured by RIA. Vital status and cause of death ascertainment were based on linkage to the National Death Index death certificate records. After a median follow-up of 4.3 years, 730 participants died (335 deaths from cancer and 112 cardiovascular-related deaths). FT4 was inversely associated with all-cause mortality (HR = 0.77, 95% confidence interval 0.63-0.95, comparing the highest vs lowest quartile of FT4; P for linear trend = .01), and FT3 was inversely associated cancer mortality (HR = 0.62, 95% confidence interval 0.45-0.85; P for linear trend = .001). TSH was not associated with mortality endpoints. In a large cohort of euthyroid men and women, FT4 and FT3 levels within the normal range were inversely associated with the risk of all-cause mortality and cancer mortality, particularly liver cancer mortality.

  16. HPLC-ICP/MS Analysis of Thyroid Hormone and Related Iodinated Compounds in Tissues and Media

    Science.gov (United States)

    Quantifying thyroid hormone (TH) and the synthetic precursors and metabolic products of TH is important for developing models of the hypothalamic-pituitary-thyroid (HPT) axis as well as for understanding the effects of xenobiotics on HPT axis function. In this study, the developm...

  17. Static and dynamic thyroid scintigraphy

    International Nuclear Information System (INIS)

    Mahlstedt, J.

    1986-01-01

    Static images as isolated investigation in thyroid diagnosis mainly provides morphologic information, and therefore sonography is largely applied for this purpose. 99m Tc-pertechnetate scans or 123 I-scans are indicated in cases of malpositions and serve to clarify lesions of unknown dignity. Additionally 201 Tl-chloride is suited for examinations with regard to metabolically active thyroid tissue, whereby differential diagnostic laboratory tests must be carried out to exclude parathyroid adenoma. Dynamic thyroid scans before and after regulation tests (suppression, stimulation) reflect the physiological correlation between the iodine avidity of the thyroid, the peripheral thyroid hormone concentrations and the hypophyseal regulation in the TRH-test. The main application of this procedure is the clarification of thyroid autonomy, i.e. indication, detection, quantification or exclusion of thyroid autonomy. For the treatment of immunogenic thyrotoxicosis, dynamic thyroid scintigraphy provides important information about the onset of remission, thus permitting to end thyreostatic therapy. (orig.) [de

  18. Thyroid hormone actions on male reproductive system of teleost fish.

    Science.gov (United States)

    Tovo-Neto, Aldo; da Silva Rodrigues, Maira; Habibi, Hamid R; Nóbrega, Rafael Henrique

    2018-04-17

    Thyroid hormones (THs) play important roles in the regulation of many biological processes of vertebrates, such as growth, metabolism, morphogenesis and reproduction. An increasing number of studies have been focused on the involvement of THs in the male reproductive system of vertebrates, in particular of fish. Therefore, this mini-review aims to summarize the main findings on THs role in male reproductive system of fish, focusing on sex differentiation, testicular development and spermatogenesis. The existing data in the literature have demonstrated that THs exert their roles at the different levels of the hypothalamic-pituitary-gonadal (HPG) axis. In general a positive correlation has been shown between THs and fish reproductive status; where THs are associated with testicular development, growth and maturation. Recently, the molecular mechanisms underlying the role of THs in spermatogenesis have been unraveled in zebrafish testis. THs promote germ cell proliferation and differentiation by increasing a stimulatory growth factor of spermatogenesis produced by Sertoli cells. In addition, THs enhanced the gonadotropin-induced androgen release in zebrafish testis. Next to their functions in the adult testis, THs are involved in the gonadal sex differentiation through modulating sex-related gene expression, and testicular development via regulation of Sertoli cell proliferation. In conclusion, this mini-review showed that THs modulate the male reproductive system during the different life stages of fish. The physiological and molecular mechanisms showed a link between the thyroid and reproduction, suggesting a possibly co-evolution and interdependence of these two systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Thyroid hormone: the modulator of erectile function in the rabbit ...

    African Journals Online (AJOL)

    The possible role of thyroid hormones in the Nitric Oxide (NO)- mediated response to sexual stimulation, and on prostaglandin E1 (PGE1) and Sildenafil in the treatment of erectile dysfunction was investigated using the corpus cavernosum of the New Zealand rabbit animal model. The parameters studied were penile ...

  20. Examining recombinant human TSH primed {sup 131}I therapy protocol in patients with metastatic differentiated thyroid carcinoma: comparison with the traditional thyroid hormone withdrawal protocol

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Deepa; Kaisar, Sushma; Awasare, Sushma; Kamaldeep; Abhyankar, Amit; Basu, Sandip [Bhabha Atomic Research Centre (BARC), Radiation Medicine Centre, Mumbai (India)

    2014-09-15

    Recombinant human thyroid-stimulating hormone (rhTSH)-based protocol is a promising recent development in the management of differentiated thyroid carcinoma (DTC). The objectives of this prospective study were: (1) to assess the feasibility and efficacy of the rhTSH primed {sup 131}I therapy protocol in patients with DTC with distant metastatic disease, (2) to perform lesional dosimetry in this group of patients compared to the traditional protocol, (3) to document the practical advantages (patient symptoms and hospital stay) of the rhTSH protocol compared to the traditional thyroid hormone withdrawal protocol, (4) to document and record any adverse effect of this strategy, (5) to compare the renal function parameters, and (6) to compare the serum TSH values achieved in either of the protocols in this group of patients. The study included 37 patients with metastatic DTC having lung or skeletal metastases or both. A comparison of lesional radiation absorbed dose, hospital stay, renal function tests, and symptom profile was undertaken between the traditional thyroid hormone withdrawal protocol and rhTSH-based therapy protocol. Dosimetric calculations of metastatic lesions were performed using lesion uptake and survey meter readings for calculation of effective half-life. Non-contrast-enhanced CT was used for assessment of tumor volume. Quality of life was assessed using the European Organization for Research and Treatment of Cancer (EORTC) QOL forms. A comparison of pretreatment withdrawal thyroglobulin (TG) was done with the withdrawal TG level 3 months after treatment. The mean effective half-life of {sup 131}I in metastatic lesions was less during the rhTSH protocol (29.49 h) compared to the thyroid hormone withdrawal protocol (35.48 h), but the difference was not statistically significant (p = 0.056). The mean 24-h % uptake of the lesions during the traditional protocol (4.84 %) was slightly higher than the 24-h % uptake during the rhTSH protocol (3.56 %), but

  1. Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

    Directory of Open Access Journals (Sweden)

    Kyle H. Elliott

    2013-04-01

    Thyroid hormones affect in vitro metabolic intensity, increase basal metabolic rate (BMR in the lab, and are sometimes correlated with basal and/or resting metabolic rate (RMR in a field environment. Given the difficulty of measuring metabolic rate in the field—and the likelihood that capture and long-term restraint necessary to measure metabolic rate in the field jeopardizes other measurements—we examined the possibility that circulating thyroid hormone levels were correlated with RMR in two free-ranging bird species with high levels of energy expenditure (the black-legged kittiwake, Rissa tridactyla, and thick-billed murre, Uria lomvia. Because BMR and daily energy expenditure (DEE are purported to be linked, we also tested for a correlation between thyroid hormones and DEE. We examined the relationships between free and bound levels of the thyroid hormones thyroxine (T4 and triiodothyronine (T3 with DEE and with 4-hour long measurements of post-absorptive and thermoneutral resting metabolism (resting metabolic rate; RMR. RMR but not DEE increased with T3 in both species; both metabolic rates were independent of T4. T3 and T4 were not correlated with one another. DEE correlated with body mass in kittiwakes but not in murres, presumably owing to the larger coefficient of variation in body mass during chick rearing for the more sexually dimorphic kittiwakes. We suggest T3 provides a good proxy for resting metabolism but not DEE in these seabird species.

  2. Doc Title: Adult Hippocampal Neurogenesis is Impaired by Transient Developmental Thyroid Hormone Disruption

    Data.gov (United States)

    U.S. Environmental Protection Agency — Severe thyroid hormone (TH) deprivation during development impairs neurogenesis throughout the brain. The hippocampus also maintains a capacity for neurogenesis...

  3. Human longevity is characterised by high thyroid stimulating hormone secretion without altered energy metabolism.

    Science.gov (United States)

    Jansen, S W; Akintola, A A; Roelfsema, F; van der Spoel, E; Cobbaert, C M; Ballieux, B E; Egri, P; Kvarta-Papp, Z; Gereben, B; Fekete, C; Slagboom, P E; van der Grond, J; Demeneix, B A; Pijl, H; Westendorp, R G J; van Heemst, D

    2015-06-19

    Few studies have included subjects with the propensity to reach old age in good health, with the aim to disentangle mechanisms contributing to staying healthier for longer. The hypothalamic-pituitary-thyroid (HPT) axis maintains circulating levels of thyroid stimulating hormone (TSH) and thyroid hormone (TH) in an inverse relationship. Greater longevity has been associated with higher TSH and lower TH levels, but mechanisms underlying TSH/TH differences and longevity remain unknown. The HPT axis plays a pivotal role in growth, development and energy metabolism. We report that offspring of nonagenarians with at least one nonagenarian sibling have increased TSH secretion but similar bioactivity of TSH and similar TH levels compared to controls. Healthy offspring and spousal controls had similar resting metabolic rate and core body temperature. We propose that pleiotropic effects of the HPT axis may favour longevity without altering energy metabolism.

  4. The Effect of Alcoholic Extract of Physalis alkekengi on Serum Concentration of Thyroid Hormones in Rats

    Directory of Open Access Journals (Sweden)

    Shahnaz Shekar-Foroosh

    2012-05-01

    Full Text Available Background: There are different factors which are effective on maintaining homeostasis, especially by pituitary-thyroid axis hormones. The objective of this study was to examine the effect of Physalis alkekengi plant extract belonging to Solanaceae family on the concentration of the pituitary-thyroid axis hormones.Materials and Methods: This study was conducted on five groups (n=10 of male Wistar rats (with mean weight 210±5g. The control group did not receive any substances, while the reference group received 0.2 ml normal saline daily and the experimental groups received maximum (0.4 g/kg, moderate (0.2 g/kg, and minimum (0.1 g/kg intraperitoneal (IP doses of the alcoholic extract for 14 days. At the end of this period, blood samples were drawn and the results were analyzed by SPSS-11.5 software.Results: The results of statistical analysis showed significant increases in plasma concentrations of thyroxin (T4 and triiodothyronine (T3 in the maximum dose group (p<0.05 with no significant changes in plasma concentrations of thyroid-stimulating hormone (TSH.Conclusion: Increases in T3 and T4 levels with no changes in TSH concentration indicate hyperthyroidism euthyroidism in which the levels of thyroid hormones increase while the amount of TSH remains constant. These changes could be due to plasma proteins increase including albumin, which are probably induced by physaline and alkaloids existing in Physalis alkekengi. So, these drug doses do not seem to bring about pathological changes in the pituitary-thyroid axis.

  5. Physiologic implications of inter-hormonal interference in fish: lessons from the interaction of adrenaline with cortisol and thyroid hormones in climbing perch (Anabas testudineus Bloch).

    Science.gov (United States)

    George, Nimta; Peter, Valsa S; Peter, M C Subhash

    2013-01-15

    Adrenaline and cortisol, the major stress hormones, are known for its direct control on stress response in fish. Likewise, as an important stress modifier hormone, thyroid hormone has also been implicated in stress response of fish. We tested whether the hypothesis on the phenomenon of inter-hormonal interference, a process that explains the hormonal interactions, operates in fish particularly between adrenaline, cortisol and thyroid hormones. To achieve this goal, indices of acid-base, osmotic and metabolic regulations were quantified after adrenaline challenge in propranolol pre-treated air-breathing fish (Anabas testudineus). Short-term adrenaline (10 ng g(-1)) injection for 30 min produced a rise in plasma cortisol without affecting plasma T(3) and T(4). On the contrary, blocking of adrenaline action with a non-selective blocker, propranolol (25 ng g(-1)) for 90 min reduced plasma cortisol along with plasma T(4) and that indicate a possible interference of these hormones in the absence of adrenaline challenge. Similarly, a reduction in plasma T(3) was found after adrenaline challenge in propranolol pre-treated fish and that suggests a functional synergistic interference of adrenaline with T(3). Adrenaline challenge in these fish, however, failed to abolish this propranolol effect. The remarkable systemic hypercapnia and acidosis by propranolol pre-treatment were reversed by adrenaline challenge, pointing to a direct action of adrenaline on acid-base indices probably by a mechanism which may not require β-adrenergic receptor systems. Interestingly, the prominent adrenaline-induced hyperglycemia, hyperlactemia and hyperuremea were not altered by propranolol treatment. Similarly, adrenaline challenge promoted and propranolol reduced the osmotic competencies of the gills, kidneys and liver of this fish as evident in the sodium and proton pump activities. The modified physiologic actions of adrenaline and its modified interaction with THs and cortisol in blocked

  6. Do Thyroxine and Thyroid-Stimulating Hormone Levels Reflect Urinary Iodine Concentrations?

    Science.gov (United States)

    Soldin, Offie P.; Tractenberg, Rochelle E.; Pezzullo, John C.

    2013-01-01

    The toxicity of environmental chemicals such as nitrates, thiocynates, and perchlorates, some therapeutics, and dietary goitrogens can lower thyroidal iodine uptake and result in hypothyroidism and goiter. Iodine sufficiency, essential for normal thyroid hormone synthesis, is critical during gestation to assure that sufficient thyroxine (T4) and iodine reach the developing fetus. Spot urinary iodide (UI) measurements are used globally to indicate and monitor iodine sufficiency of populations. In individuals, however, UI are not routinely measured; instead, normal serum thyroid-stimulating hormone (TSH) and T4 concentrations serve as surrogate indicators of iodine sufficiency as well as thyroidal health. Our objective was to examine the relationship between UI concentrations and serum T4 and TSH concentrations in individuals in an ‘‘iodine-sufficient population.’’ Using a cross-sectional sample of the US population (n = 7628) from the National Health and Nutrition Examination Survey (NHANES III; 1988–1994) database, we examined the relationship among UI, T4, and TSH in pregnant and nonpregnant women and in men (15–44 years). There was a lack of relationship between UI (or UI/Cr) concentrations and serum T4 or TSH concentrations. Therefore, TSH and T4 are not appropriate markers of UI concentrations in this population. Monitoring the status of iodine nutrition of individuals in the United States may be important because serum TSH and T4 concentrations do not indicate low iodine status. PMID:15795649

  7. Magnetic resonance imaging of cerebral anomalies in subjects with resistance to thyroid hormone

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, C.M. [Univ. of Florida Health Science Center, Gainesville, FL (United States); Hauser, P.; Weintraub, B.D. [National Institute of Mental Health, Bethesda, MD (United States)]|[Baltimore VA Medical Center, MD (United States)] [and others

    1995-06-19

    Resistance to thyroid hormone (RTH) is an autosomal dominant disease caused by mutations in the human thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of attention deficit hyperactivity disorder (ADHD). The purpose of this study was to search for developmental brain malformations associated with RTH. Forty-three subjects (20 affected males [AM], 23 affected females [AF]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of six contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) and multiple Heschl`s transverse gyri (primary auditory cortex) were noted. There was a significantly increased frequency of anomalous Sylvian fissures in the left hemisphere in males with RTH (AM: 70%; AF: 30%; UM: 28% UF: 28%). Also, there was an increased frequency of anomalous Sylvian fissures on the left combined with multiple Heschl`s gyri in either hemisphere in males with RTH (AM: 50%; AF: 9%; UM: 6%; UF: 0%). However, RTH subjects with anomalies did not have an increased frequency of ADHD as compared with RTH subjects with no anomalies. Abnormal thyroid hormone action in the male fetus early during brain development may be associated with grossly observable cerebral anomalies of the left hemisphere. The effects of mutations in the thyroid receptor beta gene provide a model system for studying the complex interaction of genetic and non-genetic factors on brain and behavioral development. 19 refs., 2 figs., 2 tabs.

  8. Plurihormonal pituitary adenoma immunoreactive for thyroid-stimulating hormone, growth hormone, follicle-stimulating hormone, and prolactin.

    Science.gov (United States)

    Luk, Cynthia T; Kovacs, Kalman; Rotondo, Fabio; Horvath, Eva; Cusimano, Michael; Booth, Gillian L

    2012-01-01

    To describe the case of a patient with an unusual plurihormonal pituitary adenoma with immunoreactivity for thyroid-stimulating hormone (TSH), growth hormone, follicle-stimulating hormone, prolactin, and α-subunit. We report the clinical, laboratory, imaging, and pathology findings of a patient symptomatic from a plurihormonal pituitary adenoma and describe her outcome after surgical treatment. A 60-year-old woman presented to the emergency department with headaches, blurry vision, fatigue, palpitations, sweaty hands, and weight loss. Her medical history was notable for hyperthyroidism, treated intermittently with methimazole. Magnetic resonance imaging disclosed a pituitary macroadenoma (2.3 by 2.2 by 2.0 cm), and preoperative blood studies revealed elevated levels of TSH at 6.11 mIU/L, free thyroxine at 3.6 ng/dL, and free triiodothyronine at 6.0 pg/mL. She underwent an uncomplicated transsphenoidal resection of the pituitary adenoma. Immunostaining of tumor tissue demonstrated positivity for not only TSH but also growth hormone, follicle-stimulating hormone, prolactin, and α-subunit. The Ki-67 index of the tumor was estimated at 2% to 5%, and DNA repair enzyme O6-methylguanine-DNA methyltransferase immunostaining was mostly negative. Electron microscopy showed the ultrastructural phenotype of a glycoprotein-producing adenoma. Postoperatively, her symptoms and hyperthyroidism resolved. Thyrotropin-secreting pituitary adenomas are rare. Furthermore, recent reports suggest that 31% to 36% of adenomas may show evidence of secretion of multiple pituitary hormones. This case emphasizes the importance of considering pituitary causes of thyrotoxicosis and summarizes the clinical and pathology findings in a patient with a plurihormonal pituitary adenoma.

  9. Epigenetic involvement of Alien/ESET complex in thyroid hormone-mediated repression of E2F1 gene expression and cell proliferation

    International Nuclear Information System (INIS)

    Hong, Wei; Li, Jinru; Wang, Bo; Chen, Linfeng; Niu, Wenyan; Yao, Zhi; Baniahmad, Aria

    2011-01-01

    Highlights: ► Corepressor Alien interacts with histone methyltransferase ESET in vivo. ► Alien/ESET complex is recruited to nTRE of T3-responsive gene by liganded TRβ1. ► ESET-mediated H3K9 methylation is required for liganded TRβ1-repressed transcription. ► ESET is involved in T3-repressed G1/S phase transition and proliferation. -- Abstract: The ligand-bound thyroid hormone receptor (TR) is known to repress via a negative TRE (nTRE) the expression of E2F1, a key transcription factor that controls the G1/S phase transition. Alien has been identified as a novel interacting factor of E2F1 and acts as a corepressor of E2F1. The detailed molecular mechanism by which Alien inhibits E2F1 gene expression remains unclear. Here, we report that the histone H3 lysine 9 (H3K9) methyltransferase (HMT) ESET is an integral component of the corepressor Alien complex and the Alien/ESET complex is recruited to both sites, the E2F1 and the nTRE site of the E2F1 gene while the recruitment to the negative thyroid hormone response element (nTRE) is induced by the ligand-bound TRβ1 within the E2F1 gene promoter. We show that, overexpression of ESET promotes, whereas knockdown of ESET releases, the inhibition of TRβ1-regulated gene transcription upon T3 stimulation; and H3K9 methylation is required for TRβ1-repressed transcription. Furthermore, depletion of ESET impairs thyroid hormone-repressed proliferation as well as the G1/S transition of the cell cycle. Taken together, our data indicate that ESET is involved in TRβ1-mediated transcription repression and provide a molecular basis of thyroid hormone-induced repression of proliferation.

  10. Elevated levels of circulating thyroid hormone do not cause the medical sequelae of hyperthyroidism.

    Science.gov (United States)

    Kelly, Tammas; Denmark, Lawrence; Lieberman, Daniel Z

    2016-11-03

    Clinicians have been reluctant to use high dose thyroid (HDT) to treat affective disorders because high circulating levels of thyroid hormone have traditionally been equated with hyperthyroidism, and understood as the cause of the medical sequelae of hyperthyroidism, such as osteoporosis and cardiac abnormalities. This conclusion is not supported by (HDT) research. A literature review of research related to the morbidity and mortality of HDT treatment was performed. There exists a large body of research involving the use of HDT treatment to prevent the recurrence of differentiated thyroid cancer and to treat affective disorders. A review of this literature finds a lack of support for HDT as a cause of osteoporosis, nor is there support for an increase in morbidity or mortality associated with HDT. This finding contrasts with the well-established morbidity and mortality associated with Graves' disease, thyroiditis, and other endogenous forms of hyperthyroidism. The lack of evidence that exogenous HDT causes osteoporosis, cardiac abnormalities or increases mortality compared with the significant morbidity and mortality of hyperthyroidism requires an alternative cause for the medical sequelae of hyperthyroidism. One possibility is an autoimmune mechanism. High circulating levels of thyroid hormone is not the cause of the sequela of hyperthyroidism. The reluctance to using high dose thyroid is unwarranted. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Study on the relationship between serum levels of leptin thyroid hormones

    International Nuclear Information System (INIS)

    Lin Pingan; Zhai Chuntao; Yuan Sufen

    2005-01-01

    Objective: To evaluate the relationship between serum levels of leptin and thyroid functional status. Methods: Serum leptin (with RIA) and pituitary-thyroid axis hormones (with CLIA) were measured in 75 euthyroid controls, 44 hyperthyroid subjects and 27 hypothyroid subjects. Results: The levels of leptin in euthyroid controls, hyperthyroid subjects and hypothyroid subjects were (5.40 ± 3.78) ng/ml, (5.99 ± 5.24) ng/ml and (5.59 ± 4.23) ng/ml respectively with no significant differences among them. The serum leptin levels were positively correlated with serum TSH levels (r=0.27, P<0.01). Conclusion: Thyroid function has no effect on serum leptin levels and TSH levels correlates closely with those of serum leptin. (authors)

  12. A two-day-old hyperthyroid neonate with thyroid hormone resistance born to a mother with well-controlled Graves’ disease: a case report

    Directory of Open Access Journals (Sweden)

    Yatsuga Shuichi

    2012-08-01

    Full Text Available Abstract Introduction Resistance to thyroid hormone is a syndrome caused by thyroid hormone receptor β mutations, which are usually inherited in an autosomal-dominant pattern. Case presentation Our patient, a Japanese neonate boy, showed hyperthyroid symptoms at age two days. Although our patient was diagnosed as having resistance to thyroid hormone, his hyperthyroid symptoms continued for two weeks. Therefore, our patient was treated with methimazole and iodine for two weeks from birth, showing no side effects and no symptoms upon treatment. At age 70 days, an R243W mutation in thyroid hormone receptor β was detected in our patient; while absent in his mother, the mutation was present in his father, who never showed any symptoms. Conclusions To the best of our knowledge this is the first case report of a resistance to thyroid hormone in a neonate presenting with hyperthyroid symptoms born to a mother with Graves’ disease and treated with methimazole and iodine. These results suggest that methimazole and iodine may be a good short-term option for treatment.

  13. Characterization of the hormone-binding domain of the chicken c-erbA/thyroid hormone receptor protein

    DEFF Research Database (Denmark)

    Muñoz, A; Zenke, M; Gehring, U

    1988-01-01

    mutations present in the carboxy-terminal half of P75gag-v-erbA co-operate in abolishing hormone binding, and that the ligand-binding domain resides in a position analogous to that of steroid receptors. Furthermore, a point mutation that is located between the putative DNA and ligand-binding domains of P75......To identify and characterize the hormone-binding domain of the thyroid hormone receptor, we analyzed the ligand-binding capacities of proteins representing chimeras between the normal receptor and P75gag-v-erbA, the retrovirus-encoded form deficient in binding ligand. Our results show that several......gag-v-erbA and that renders it biologically inactive fails to affect hormone binding by the c-erbA protein. These results suggest that the mutation changed the ability of P75gag-v-erbA to affect transcription since it also had no effect on DNA binding. Our data also suggest that hormone...

  14. Clinical significance of endogenously labelled thyroid hormones in the diagnosis of thyroidal autonomy

    International Nuclear Information System (INIS)

    Waters, W.; Kutzim, H.

    1983-01-01

    The clinical value of the determination of 123 I concentration in serum 48 hrs after tracer administration ( 123 I) 48 is investigated with special regard to thyroidal autonomy. Serum radioiodine concentration, thyroid radioiodide uptake at 4 and at 48 hrs were measured in 74 healthy subjects and patients with simple goiter, in 36 patients with thyroidal autonomy (diagnosis by thyroid suppression test), and in 20 hyperthyroid patients. 83% of the patients with elevated radioiodine concentration belonged to the group of thyroidal autonomy. The product of radioiodine concentration and thyroid radioiodide uptake is a much better parameter. 95% of the patients in which this product was elevated, belonged to the autonomy group (5% diagnostic error). Also in the control group the diagnostic error was 5%. The combination of ( 123 I) 48 with the result of the TRH-test is very useful in excluding thyroidal autonomy, if ( 123 I) 48 is normal and the TRH-test is positive (100% of the patients have regulated thyroid glands.) 94% of the patients having elevated ( 123 I) 48 and a negative TRH-test belonged to the group of thyroidal autonomy. A very useful combination for the diagnosis of borderline hyperthyroidism is the determination of the product of ( 123 I) 48 and the uptake together with the pulse rate or fine tremor of the fingers (or TRH-test). The results suggest that the determination of ( 123 I) 48 is a very good parameter of thyroidal autonomy beside the thyroid suppression test. It may be used alone for the diagnosis of thyroidal autonomy if the suppression test is contraindicated. In the diagnosis of borderline hyperthyroidism its determination makes the suppression test unnecessary in many instances. (orig.) [de

  15. Localization of the aromatase enzyme expression in the human pituitary gland and its effect on growth hormone, prolactin, and thyroid stimulating hormone axis.

    Science.gov (United States)

    Caglar, Asli Sezgin; Kapucu, Aysegul; Dar, Kadriye Akgun; Ozkaya, Hande Mefkure; Caglar, Erkan; Ince, Haluk; Kadioglu, Pinar

    2015-08-01

    The aim of this study is to evaluate aromatase expression in prolactin (PRL), thyroid stimulating hormone (TSH), and growth hormone (GH) secreting cells. Nontumoral human pituitary specimens were obtained from autopsy samples. Aromatase co-expression was determined by double immunohistochemical staining and assessed using H scores. H scores for GH-aromatase co-expression (GH-aromatase), TSH-aromatase co-expression (TSH-aromatase), and PRL-aromatase co-expression (PRL-aromatase) were 83.1 ± 13.1, 95.6 ± 16.1, and 83.7 ± 14.5, respectively. TSH producing cells exhibited the highest H score for co-expression of aromatase (p 0.05 for all). There was a negative correlation between the H scores for aromatase and PRL-aromatase, GH-aromatase and TSH-aromatase, respectively (r = -0.592, p 0.05 for all). Age was negatively correlated with PRL-aromatase H score (r = -0.373, p = 0.008). Our study demonstrated significant aromatase co-expression in PRL, GH, and TSH secreting cells of the human anterior pituitary gland. The mutual paracrinal regulation between aromatase and three adenohypophyseal hormones indicates that aromatase may have a regulatory role on the synthesis and secretion of these hormones.

  16. Serum Levels of Thyroid Hormones and Thyrotropin in Some Sickle ...

    African Journals Online (AJOL)

    The serum levels of the thyroid hormones (T4 and T3) and thyrotropin (TSH) were measured by radio-immunoassay (RIA) in the steady state of 10 homozygous sickle cell anaemia patients and 10 normal subjects of the same age group in years (15-25) who were the control group. The results showed that sickle cell disease ...

  17. Relationship between thyroid stimulating hormone and various components of metabolic syndrome

    International Nuclear Information System (INIS)

    Majeed, S.; Hashim, R.

    2015-01-01

    To determine the relation between thyroid stimulating hormone and various components of metabolic syndrome. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Pathology department, Army Medical College of National University of Sciences and Technology (NUST) Islamabad and Military Hospital (MH), Rawalpindi, Pakistan; from January to March 2013. Material and Methods: Hundred adult inhabitants (30-60 years) of Rawalpindi participated in this study. Subjects who fulfilled the WHO criteria for metabolic syndrome (MetS) were included and those who had any thyroid illness, or were using any thyroid medications were excluded from this study. For thyroid function tests (TFT's), serum thyroid stimulating hormone (TSH), total tri-iodothyronine (TT3), free throxine (FT4) were estimated. Insulin resistance (IR) was measured by Homeostasis Model Assessment for IR (HOMA-IR). Data was analyzed by SPSS-18. Results: Out of 50 subjects of control group, 26 (52%) were male and 24 (48%) were female. Basal metabolic rate (BMI), serum triglyceride (TG), HOMA-IR were higher and serum high density lipoprotein cholesterol (HDL-c) was lower in MetS patients. There was no significant difference in serum TT3 and FT4 between MetS patients and control group, however, mean serum TSH levels were higher in MetS (2.622 + 0.924 vs 5.002 + 1.074 mIU/l, p<0.001). In correlation analysis, serum TSH was positively and significantly correlated with BMI (r=0.344, p=0.014) and HOMA-IR (r=0.419, p<0.002). Conclusion: These results suggest that serum TSH correlates with various components of metabolic syndrome patients. Analysis of serum TSH levels in metabolic syndrome patients may prove beneficial in preventing the various cardiometabolic complications in such patients. (author)

  18. Thyroid evaluation with radioassay

    International Nuclear Information System (INIS)

    Ashkar, F.S.

    1983-01-01

    Thyroid hormone is given therapeutically for the treatment of hypothyroidism and in goiterous conditions. When administered in full maintenance dosage, it interrupts the operation of the homeostatic mechanism that evokes excesses of thyrotropin (TSH) in response to various goiterogenic stimuli or impending thyroid failure, resulting in thyroid gland enlargement. All patients with treated thyroid cancer are maintained indefinitely on full replacement dosages of thyroid hormone to eliminate endogenous TSH and its trophic effect, thereby minimizing recurrence and growth of the tumor. A high-risk group of patients that were irradiated to the head and neck in childhood for various reasons are placed on thyroid hormone therapy prophylactically to turn off their endogenous TSH if they are found free of thyroid nodularity on initial evaluation. The adequacy of thyroid hormone therapy and the regularity of its intake can be ultimately evaluated by the thyrotropin releasing hormone (TRH) stimulation test, where no TSH response indicates adequate therapy and a normal TSH response suggests inadequate or irregular treatment

  19. The effect of vasopressin on hormone secretion and blood flow from the thyroid vein in sheep with exteriorized thyroids.

    Science.gov (United States)

    Falconer, I R

    1968-12-01

    1. Vasopressin has been shown to activate the thyroid in some species, and also to be released into the bloodstream after emotional and other stresses.2. Emotional stimuli applied to sheep have previously been shown to increase thyroid secretion and the possible influence of vasopressin in this process has been investigated. Sheep bearing exteriorized thyroid glands were used, so that thyroid vein blood could be collected in undisturbed conscious animals.3. (125)I or (131)I (50 muc) was injected I.M. into the sheep; 4-7 days later, samples of thyroid vein blood were collected at 10 min intervals for 4 hr, and the concentration of total and protein bound (125)I or (131)I was measured. Intravenous infusions of 0.3, 3.0 or 31 m-u./min arginine or lysine vasopressin, or close arterial infusions of 3.0 or 31 m-u./min arginine vasopressin were administered 1.5 hr after commencement of blood sampling. Blood flow from the thyroid was measured by a plethysmographic technique during similar experiments.4. No significant changes in thyroid hormone secretion were observed as a result of vasopressin infusion, and it was concluded that vasopressin release does not play a part in the activation of the thyroid resulting from emotional stimulus in the sheep.

  20. Impact of Triclosan on Female Reproduction through Reducing Thyroid Hormones to Suppress Hypothalamic Kisspeptin Neurons in Mice

    Directory of Open Access Journals (Sweden)

    Xin-Yuan Cao

    2018-01-01

    Full Text Available Triclosan (TCS, a broad-spectrum antimicrobial agent, is widely used in clinical settings and various personal care products. The aim of this study was to evaluate the influence of TCS on reproductive endocrine and function. Here, we show that the exposure of adult female mice to 10 or 100 mg/kg/day TCS caused prolongation of diestrus, and decreases in antral follicles and corpora lutea within 2 weeks. TCS mice showed decreases in the levels of serum luteinizing hormone (LH, follicle-stimulating hormone (FSH and progesterone, and gonadotrophin-releasing hormone (GnRH mRNA with the lack of LH surge and elevation of prolactin (PRL. TCS mice had lower kisspeptin immunoreactivity and kiss1 mRNA in anteroventral periventricular nucleus (AVPV and arcuate nucleus (ARC. Moreover, the estrogen (E2-enhanced AVPV-kisspeptin expression was reduced in TCS mice. In addition, the serum thyroid hormones (triiodothyronine (T3 and thyroxine (T4 in TCS mice were reduced with increases in levels of thyroid stimulating hormone (TSH and thyroid releasing hormone (TRH. In TCS mice, the treatment with Levothyroxine (L-T4 corrected the increases in PRL, TSH and TRH; the administration of L-T4 or type-2 dopamine receptors agonist quinpirole inhibiting PRL release could rescue the decline of kisspeptin expression in AVPV and ARC; the treatment with L-T4, quinpirole or the GPR45 agonist kisspeptin-10 recovered the levels of serum LH and FSH and progesterone, and GnRH mRNA. Furthermore, TCS mice treated with L-T4 or quinpirole resumed regular estrous cycling, follicular development and ovulation. Together, these results indicate that exposing adult female mice to TCS (≥10 mg/kg reduces thyroid hormones causing hyperprolactinemia that then suppresses hypothalamic kisspeptin expression, leading to deficits in reproductive endocrine and function.

  1. [Impact of thyroid diseases on bone].

    Science.gov (United States)

    Tsourdi, E; Lademann, F; Siggelkow, H

    2018-05-09

    Thyroid hormones are key regulators of skeletal development in childhood and bone homeostasis in adulthood, and thyroid diseases have been associated with increased osteoporotic fractures. Hypothyroidism in children leads to an impaired skeletal maturation and mineralization, but an adequate and timely substitution with thyroid hormones stimulates bone growth. Conversely, hyperthyroidism at a young age accelerates skeletal development, but may also cause short stature because of a premature fusion of the growth plates. Hypothyroidism in adults causes an increase in the duration of the remodeling cycle and, thus, leads to low bone turnover and enhanced mineralization, but an association with a higher fracture risk is less well established. In adults, a surplus of thyroid hormones enhances bone turnover, mostly due to an increased bone resorption driven by osteoclasts. Thus, hyperthyroidism is a well-recognized cause of high-bone turnover secondary osteoporosis, resulting in an increased susceptibility to fragility fractures. Subclinical hyperthyroidism, especially resulting from endogenous disease, also has an adverse effect on bone mineral density and is associated with fractures. In most patients with overt or subclinical hyperthyroidism restoration of the euthyroid status reverses bone loss. In postmenopausal women who receive thyroid-stimulating hormone suppression therapy because of thyroid cancer, antiresorptive treatments may be indicated. Overall, extensive data support the importance of a euthyroid status for bone mineral accrual and growth in childhood as well as maintenance of bone health in adulthood.

  2. Pregnancy and Thyroid Disease

    Science.gov (United States)

    ... People Who Were Treated with hGH Thyroid Disease & Pregnancy Thyroid disease is a group of disorders that ... prescribes. What role do thyroid hormones play in pregnancy? Thyroid hormones are crucial for normal development of ...

  3. Over-the-Counter "Adrenal Support" Supplements Contain Thyroid and Steroid-Based Adrenal Hormones.

    Science.gov (United States)

    Akturk, Halis Kaan; Chindris, Ana Maria; Hines, Jolaine M; Singh, Ravinder J; Bernet, Victor J

    2018-03-01

    To assess whether dietary supplements that are herbal and/or animal-derived products, marketed for enhancing metabolism or promoting energy, "adrenal fatigue," or "adrenal support," contain thyroid or steroid hormones. Twelve dietary adrenal support supplements were purchased. Pregnenolone, androstenedione, 17-hydroxyprogesterone, cortisol, cortisone, dehydroepiandrosterone sulfate, synthetic glucocorticoids (betamethasone, dexamethasone, fludrocortisone, megestrol acetate, methylprednisolone, prednisolone, prednisone, budesonide, and triamcinolone acetonide) levels were measured twice in samples in a blinded fashion. This study was conducted between February 1, 2016, and November 1, 2016. Among steroids, pregnenolone was the most common hormone in the samples. Budesonide, 17-hydroxyprogesterone, androstenedione, cortisol, and cortisone were the others in order of prevalence. All the supplements revealed a detectable amount of triiodothyronine (T3) (63-394.9 ng/tablet), 42% contained pregnenolone (66.12-205.2 ng/tablet), 25% contained budesonide (119.5-610 ng/tablet), 17% contained androstenedione (1.27-7.25 ng/tablet), 8% contained 17-OH progesterone (30.09 ng/tablet), 8% contained cortisone (79.66 ng/tablet), and 8% contained cortisol (138.5 ng/tablet). Per label recommended doses daily exposure was up to 1322 ng for T3, 1231.2 ng for pregnenolone, 1276.4 ng for budesonide, 29 ng for androstenedione, 60.18 ng for 17-OH progesterone, 277 ng for cortisol, and 159.32 ng for cortisone. All the supplements studied contained a small amount of thyroid hormone and most contained at least 1 steroid hormone. This is the first study that measured thyroid and steroid hormones in over-the-counter dietary "adrenal support" supplements in the United States. These results may highlight potential risks of hidden ingredients in unregulated supplements. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  4. Elevated thyroid stimulating hormone in a neonate: Drug induced or disease?

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Kota

    2011-01-01

    Full Text Available Dyshormonogenesis is an uncommon cause of congenital hypothyroidism. The most common abnormality is absent or insufficient thyroid peroxidase enzyme. Maternal intake of antithyroid drug can also lead to elevated thyroid stimulating hormone (TSH in a neonate, albeit the scenario is temporary. We report one such interesting case where a clinically euthyroid neonate borne to a mother on antithyroid drug presents on 12 th day of life with reports of elevated TSH and increased tracer uptake in 99mTc thyroid scan. Disproportionately high TSH in comparison to low maternal antithyroid drug dosage and further elevation of TSH after stopping mother′s antithyroid drugs ruled out maternal antithyroid drug-induced congenital hypothyroidism in the baby. Early institution of therapy in these patients can prevent mental retardation and other features of hypothyroidism.

  5. Impairment of iodine and thyroid hormone metabolism in very premature infants

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Stanislav

    2008-01-01

    Roč. 24, Suppl.1 (2008), S46-S47 ISSN 0742-2091. [Trace Elements in Diet, Nutrition and Health. 21.10.2008-26.10.2008, Hersonissos] Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * newborn * iodine * thyroid hormone Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  6. Role of Oxidative Stress in Thyroid Hormone-Induced Cardiomyocyte Hypertrophy and Associated Cardiac Dysfunction: An Undisclosed Story

    Directory of Open Access Journals (Sweden)

    Mohammad T. Elnakish

    2015-01-01

    Full Text Available Cardiac hypertrophy is the most documented cardiomyopathy following hyperthyroidism in experimental animals. Thyroid hormone-induced cardiac hypertrophy is described as a relative ventricular hypertrophy that encompasses the whole heart and is linked with contractile abnormalities in both right and left ventricles. The increase in oxidative stress that takes place in experimental hyperthyroidism proposes that reactive oxygen species are key players in the cardiomyopathy frequently reported in this endocrine disorder. The goal of this review is to shed light on the effects of thyroid hormones on the development of oxidative stress in the heart along with the subsequent cellular and molecular changes. In particular, we will review the role of thyroid hormone-induced oxidative stress in the development of cardiomyocyte hypertrophy and associated cardiac dysfunction, as well as the potential effectiveness of antioxidant treatments in attenuating these hyperthyroidism-induced abnormalities in experimental animal models.

  7. The Effect of Tamoxifen Administration and γ-Irradiation on Thyroid Hormones Levels in Rats Bearing Mammary Tumours

    International Nuclear Information System (INIS)

    Abdelgawad, M.R.

    2013-01-01

    Breast Cancer is the most common malignancy among women in most developed and developing regions of the world, in female, tamoxifen acting as an oestrogen antagonist on the breast. Thyroid hormones can stimulate the proliferation in vitro of certain tumor cell lines. The aim of the present study is to evaluate the effect of tamoxifen and/ or irradiation treatment on thyroid hormones in rats' mammary tumours. Forty-two female Sprague-Dawely rats randomly divided into seven groups' proliferation (6 rats each). Control group, normal rats supplemented with tamoxifen for 3 weeks, normal rats exposed to a single dose 3Gy γ-rays, rats treated with Dimethylbenz (a) anthracene (DMBA) dissolved in corn oil (30ppm) sc and followed for 6 months until breast cancer occurrence, breast cancer bearing rats supplemented with tamoxifen for 3 weeks twice a day, breast cancer bearing rats exposed to a single dose 3Gy γ-rays, breast cancer bearing rats exposed to a single dose 3Gy γ-rays and supplemented with tamoxifen for 3 weeks twice a day. At the end of the experiment, mammary tumours and control rats were sacrificed after 3 weeks from different treatments and serum thyroid hormones and estradiol (E2) levels were assayed using commercial kits. Results show T4 and E2 levels not triiodothyronine (T3) were altered in different experimental groups. It could be concluded that γ-irradiation promote the expression of neoplastic potential by affecting both E2 and thyroid hormones and tamoxifen may alter the thyroid hormones. Tamoxifen administration and γ-irradiation may have worth effects on thyroxin (T4) and E2 levels. It is recommended to further studies towards the bystander effect of γ-rays exposure and tamoxifen treatment on the tissue culture and molecular biology scale.

  8. Avoiding the pitfalls when quantifying thyroid hormones and their metabolites using mass spectrometric methods: The role of quality assurance.

    Science.gov (United States)

    Richards, Keith; Rijntjes, Eddy; Rathmann, Daniel; Köhrle, Josef

    2017-12-15

    This short review aims to assess the application of basic quality assurance (QA) principles in published thyroid hormone bioanalytical methods using mass spectrometry (MS). The use of tandem MS, in particular linked to liquid chromatography has become an essential bioanalytical tool for the thyroid hormone research community. Although basic research laboratories do not usually work within the constraints of a quality management system and regulated environment, all of the reviewed publications, to a lesser or greater extent, document the application of QA principles to the MS methods described. After a brief description of the history of MS in thyroid hormone analysis, the article reviews the application of QA to published bioanalytical methods from the perspective of selectivity, accuracy, precision, recovery, instrument calibration, matrix effects, sensitivity and sample stability. During the last decade the emphasis has shifted from developing methods for the determination of L-thyroxine (T 4 ) and 3,3',5-triiodo-L-thyronine (T 3 ), present in blood serum/plasma in the 1-100 nM concentration range, to metabolites such as 3-iodo-L-thyronamine (3-T 1 AM), 3,5-diiodo-L-thyronine (3,5-T 2 ) and 3,3'-diiodo-L-thyronine (3,3'-T 2 ). These metabolites seem likely to be present in the low pM concentrations; consequently, QA parameters such as selectivity and sensitivity become more critical. The authors conclude that improvements, particularly in the areas of analyte selectivity, matrix effect measurement/documentation and analyte recovery would be beneficial. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Regulation mechanisms of pituitary-thyroid axis in normal subjects and patients with Graves' disease

    International Nuclear Information System (INIS)

    Takagi, Shinko; Yamauchi, Kazuyuki; Mori, Yuichi

    1986-01-01

    The regulatory mechanism of the pituitary-thyroid axis in normal subjects and patients with Graves' disease was investigated using a highly sensitive TSH assay based on the immunoradiometric assay. All of the normal subjects had detectable TSH values within the range 0.35 to 6.0 μU/ml. No negative correlations between TSH and free thyroid hormones existed in normal subjects. Patients with thyroid carcinoma who seemed to have normal pituitary-thyroid function showed a rapid increase of TSH after total thyroidectomy. On the other hand, while untreated patients with Graves' disease all had undetectable TSH values, these patients took 1 to 3.5 months longer to normalize their TSH values than to normalize free thyroid hormones on antithyroid drug therapy. During the recovery phase by the treatment with decrease of antithyroid drug or supplement of T 4 from iatrogenic hypothyroid state after treatment for Graves' disease and thyroid carcinoma, normalization of TSH levels was delayed than that of free thyroid hormones. Patients with Graves' disease in remission showed an extremely positive correlation between basal and peak TSH levels in TRH test, and a negative correlation between basal TSH and FT 4 . In conclusion, an individual patient may have a different set point concerning the regulatory mechanism of the pituitary-thyroid axis, and the persistence of the hyperthyroid state would seem to have caused some reversible dysfunction of the pituitary gland. (author)

  10. Sex- and age-dependent effects of thyroid hormone on glial morphology and function

    OpenAIRE

    Noda, Mami; Mori, Yuki; Yoshioka, Yusaku

    2016-01-01

    Thyroid hormones (THs) are essential for the development and function of the central nervous system (CNS), not only for neuronal cells but also for glial development and differentiation. In adult CNS, both hypo- and hyper-thyroidism may affect psychological condition and potentially increase the risk of cognitive impairment and neurodegeneration including Alzheimer’s disease (AD). We have reported non-genomic effects of tri-iodothyronine (T3) on microglial functions and its signaling in vitro...

  11. Influence of thyroid hormones and transforming growth factor-β1 on cystatin C concentrations.

    Science.gov (United States)

    Kotajima, N; Yanagawa, Y; Aoki, T; Tsunekawa, K; Morimura, T; Ogiwara, T; Nara, M; Murakami, M

    2010-01-01

    Serum cystatin C concentrations are reported to increase in the hyperthyroid state. Serum concentrations of cystatin C and transforming growth factor-β1 (TGF-β1) were measured in patients with thyroid dysfunction, and the effects of 3,5,3'-tri-iodothyronine (T(3)) and TGF-β1 on cystatin C production in human hepatoblastoma (Hep G2) cells were studied. Serum concentrations of cystatin C and TGF-β1 were significantly higher in patients with Graves' disease compared with control subjects. Significantly positive correlations were observed between thyroid hormones and cystatin C, thyroid hormones and TGF-β1, and TGF-β1 and cystatin C in patients with thyroid dysfunction. Serum concentrations of cystatin C and TGF-β1 decreased after treatment for hyperthyroidism. Cystatin C mRNA levels and cystatin C secretion were increased by T(3) and TGF-β1 in cultured Hep G2 cells. These results suggest that serum cystatin C concentrations increase in patients with hyperthyroidism. The mechanisms for this may involve elevation of serum TGF-β1 levels and the stimulatory effects of T(3) and TGF-β1 on cystatin C production.

  12. The preliminary evaluation on sclerodermas of newborn baby with thyroid hormone and β2-MG ria

    International Nuclear Information System (INIS)

    Liu Junchi; Du Sujun

    1995-01-01

    The combined determination of thyroid hormone and β 2 -MG may be used as the sensitive indication of the early degeneration of liver and kidney function. It is probably due to the damage of liver and kidney by scleroderma in newborn baby. The observation of 68 cases show that the serum levels of T 3 ,FT 3 in the concentration of thyroid hormone decreased significantly, and syndrome of the low serum T 3 , high serum rT 3 are taken place. Whereas, the serum level of β 2 -MG is increased significantly

  13. The study of the patient and his parents' gene with thyroid hormone resistance syndrome with review of literature

    International Nuclear Information System (INIS)

    Yang Chenwei; Zhang Xi

    2012-01-01

    Objective: To study the genoty of a family of the thyroid hormone receptor β (TRβ) gene and the clinical representation in a patient with thyroid hormone resistance syndrome (THRS). Methods : The peripheral blood samples of the patient and her parents were collected, then DNA was isolated. PCR and direct sequencing techniques were performed to determine if there were mutations in their THRβ gene. Results: There was a point mutation in exon 3d TRβ of the patient and her father, there was a base inserting in the third exon of the third chromosome. Her mother was normal. Conclusion: THRS is a disease related to thyroid hormone receptor gene mutation. The final diagnosis of this disease depends on gene analysis. (authors)

  14. A Prospective Investigation of Graves' Disease and Selenium: Thyroid Hormones, Auto-Antibodies and Self-Rated Symptoms

    DEFF Research Database (Denmark)

    Calissendorff, Jan; Mikulski, Emil; Larsen, Erik Huusfeldt

    2015-01-01

    -stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroid receptor antibodies and thyroid peroxidase auto-antibodies before medication and at 6, 18 and 36 weeks after commencing treatment with methimazole and levo-thyroxine, with a randomized blinded oral administration of 200 µg Se...

  15. Thyroid hormones in the elderly sick: "T4 euthyroidism".

    Science.gov (United States)

    Burrows, A W; Shakespear, R A; Hesch, R D; Cooper, E; Aickin, C M; Burke, C W

    1975-11-22

    Thyroid function and serum levels of triiodothyronine (T3) and thyroxine (T4) were investigated in 79 euthyroid geriatric patients. Of the 59 inpatients and 20 outpatients 35 (59%) and 2, respectively, had low T3 levels. In contrast, 7 (12%) and 6 (30%), respectively, had raised T4 levels. Two further patients were excluded from the study because of raised levels of thyroid-stimulating hormone. Thyroxine-binding globulin was greatly increased in both groups of patients, but low serum albumin levels were present in 31 (39%). Despite these changes free T3 and T4 indices closely followed total T3 and T4 levels. The difference between the two groups of patients did not correlate with body weight, diagnostic categories, age, drug treatment, or duration of stay in hospital.

  16. Effect of Ecklonia kurome extract on thyroid hormone disorder in rats

    African Journals Online (AJOL)

    Effect of Ecklonia kurome extract on thyroid hormone disorder in rats. Wen-bo ... Results: T3 and T4 serum levels in mice decreased after the administration of EKE. The relative ... mg/kg) group, and various concentrations of ... to the peroxidation of membrane lipids, according .... peripheral tissues by outer ring mono-.

  17. Cancer risk and clinicopathological characteristics of thyroid nodules harboring thyroid-stimulating hormone receptor gene mutations.

    Science.gov (United States)

    Mon, Sann Y; Riedlinger, Gregory; Abbott, Collette E; Seethala, Raja; Ohori, N Paul; Nikiforova, Marina N; Nikiforov, Yuri E; Hodak, Steven P

    2018-05-01

    Thyroid-stimulating hormone receptor (TSHR) gene mutations play a critical role in thyroid cell proliferation and function. They are found in 20%-82% of hyperfunctioning nodules, hyperfunctioning follicular thyroid cancers (FTC), and papillary thyroid cancers (PTC). The diagnostic importance of TSHR mutation testing in fine needle aspiration (FNA) specimens remains unstudied. To examine the association of TSHR mutations with the functional status and surgical outcomes of thyroid nodules, we evaluated 703 consecutive thyroid FNA samples with indeterminate cytology for TSHR mutations using next-generation sequencing. Testing for EZH1 mutations was performed in selected cases. The molecular diagnostic testing was done as part of standard of care treatment, and did not require informed consent. TSHR mutations were detected in 31 (4.4%) nodules and were located in exons 281-640, with codon 486 being the most common. Allelic frequency ranged from 3% to 45%. Of 16 cases (12 benign, 3 FTC, 1 PTC) with surgical correlation, 15 had solitary TSHR mutations and 1 PTC had comutation with BRAF V600E. Hyperthyroidism was confirmed in all 3 FTC (2 overt, 1 subclinical). Of 5 nodules with solitary TSHR mutations detected at high allelic frequency, 3 (60%) were FTC. Those at low allelic frequency (3%-22%) were benign. EZH1 mutations were detected in 2 of 4 TSHR-mutant malignant nodules and neither of 2 benign nodules. We report that TSHR mutations occur in ∼5% thyroid nodules in a large consecutive series with indeterminate cytology. TSHR mutations may be associated with an increased cancer risk when present at high allelic frequency, even when the nodule is hyperfunctioning. Benign nodules were however most strongly correlated with TSHR mutations at low allelic frequency. © 2018 Wiley Periodicals, Inc.

  18. Thyroid hormones induce browning of white fat

    Science.gov (United States)

    Martínez-Sánchez, Noelia; Moreno-Navarrete, José M; Contreras, Cristina; Rial-Pensado, Eva; Fernø, Johan; Nogueiras, Rubén; Diéguez, Carlos

    2016-01-01

    The canonical view about the effect of thyroid hormones (THs) on thermogenesis assumes that the hypothalamus acts merely as a modulator of the sympathetic outflow on brown adipose tissue (BAT). Recent data have challenged that vision by demonstrating that THs act on the ventromedial nucleus of the hypothalamus (VMH) to inhibit AMP-activated protein kinase (AMPK), which regulates the thermogenic program in BAT, leading to increased thermogenesis and weight loss. Current data have shown that in addition to activation of brown fat, the browning of white adipose tissue (WAT) might also be an important thermogenic mechanism. However, the possible central effects of THs on the browning of white fat remain unclear. Here, we show that 3,3′,5,5′ tetraiodothyroxyne (T4)-induced hyperthyroidism promotes a marked browning of WAT. Of note, central or VMH-specific administration of 3,3′,5-triiodothyronine (T3) recapitulates that effect. The specific genetic activation of hypothalamic AMPK in the VMH reversed the central effect of T3 on browning. Finally, we also showed that the expression of browning genes in human WAT correlates with serum T4. Overall, these data indicate that THs induce browning of WAT and that this mechanism is mediated via the central effects of THs on energy balance. PMID:27913573

  19. Thyroid hormone-induced oxidative damage on lipids, glutathione and DNA in the mouse heart.

    Science.gov (United States)

    Gredilla, R; Barja, G; López-Torres, M

    2001-10-01

    Oxygen radicals of mitochondrial origin are involved in oxidative damage. In order to analyze the possible relationship between metabolic rate, oxidative stress and oxidative damage, OF1 female mice were rendered hyper- and hypothyroid by chronic administration of 0.0012% L-thyroxine (T4) and 0.05% 6-n-propyl-2-thiouracil (PTU), respectively, in their drinking water for 5 weeks. Hyperthyroidism significantly increased the sensitivity to lipid peroxidation in the heart, although the endogenous levels of lipid peroxidation were not altered. Thyroid hormone-induced oxidative stress also resulted in higher levels of GSSG and GSSG/GSH ratio. Oxidative damage to mitochondrial DNA was greater than that to genomic DNA. Hyperthyroidism decreased oxidative damage to genomic DNA. Hypothyroidism did not modify oxidative damage in the lipid fraction but significantly decreased GSSG and GSSG/GSH ratio and oxidative damage to mitochondrial DNA. These results indicate that thyroid hormones modulate oxidative damage to lipids and DNA, and cellular redox potential in the mouse heart. A higher oxidative stress in the hyperthyroid group is presumably neutralized in the case of nuclear DNA by an increase in repair activity, thus protecting this key molecule. Treatment with PTU, a thyroid hormone inhibitor, reduced oxidative damage in the different cell compartments.

  20. Polybrominated diphenyl ethers (PBDEs) in grey seals during their first year of life-are they thyroid hormone endocrine disrupters?

    International Nuclear Information System (INIS)

    Hall, Ailsa J.; Kalantzi, Olga I.; Thomas, Gareth O.

    2003-01-01

    Results are consistent with a link between thyroid hormones and exposure to PBDEs in grey seal pups. - Blubber biopsy and blood samples were collected from weaned grey seal pups and juveniles in 1998 and 1999. The relationship between the concentration of total PDBEs in the blubber and the circulating concentrations of serum proteins, minerals and thyroid hormones was investigated. Fifty-four post-weaned pups were sampled and 55 first year juveniles, of which 13 were recaptured post-weaned pups. The median concentration of total PBDEs in the pups' blubber was 170 and 460 ng g -1 in the first-year animals. Total blubber PBDEs contributed significantly to the prediction of circulating thyroid hormone concentrations, after controlling for age and condition. Cholesterol and albumin concentrations were also positively related to blubber PBDEs. The results of this study suggest a link between thyroid hormones and exposure to PBDEs in grey seals during their first year of life. Such an association is not alone sufficient evidence for a cause and effect relationship, however it is in accordance with the hypothesis that these compounds are endocrine disrupters in grey seal pups

  1. The thyroid hormone, parathyroid hormone and vitamin D associated hypertension

    Directory of Open Access Journals (Sweden)

    Sandeep Chopra

    2011-01-01

    Full Text Available Thyroid disorders and primary hyperparathyroidism have been known to be associated with increases in blood pressure. The hypertension related to hypothyroidism is a result of increased peripheral resistance, changes in renal hemodynamics, hormonal changes and obesity. Treatment of hypothyroidism with levo-thyroxine replacement causes a decrease in blood pressure and an overall decline in cardiovascular risk. High blood pressure has also been noted in patients with subclinical hypothyroidism. Hyperthyroidism, on the other hand, is associated with systolic hypertension resulting from an expansion of the circulating blood volume and increase in stroke volume. Increased serum calcium levels associated with a primary increase in parathyroid hormone levels have been also associated with high blood pressure recordings. The mechanism for this is not clear but the theories include an increase in the activity of the renin-angiotensin-aldosterone system and vasoconstriction. Treatment of primary hyperparathyroidism by surgery results in a decline in blood pressure and a decrease in the plasma renin activity. Finally, this review also looks at more recent evidence linking hypovitaminosis D with cardiovascular risk factors, particularly hypertension, and the postulated mechanisms linking the two.

  2. The Relationship between Aggression and Serum Thyroid Hormone Level in Individuals Diagnosed with Antisocial Personality Disorder.

    Science.gov (United States)

    Evrensel, Alper; Ünsalver, Barış Önen; Özşahin, Aytekin

    2016-06-01

    Aggression is one of the leading clinical characteristics of antisocial personality disorder (APD). Studies aiming to clarify and control the biological basis of aggression are ongoing. Thyroid hormones have been indicated to play a role in the development of aggression. The aim of this study was to examine the level of aggression and serum thyroid hormone in a sample of APD and to make contributions to this field with the current findings. The sample consisted of 96 subjects with a diagnosis of APD and 97 subjects as a control group. Structured Clinical Interview for DSM-IV Axis (SCID) 1 and 2 were used for the diagnosis, and the Buss-Perry Aggression Questionnaire was administered. Based on criminal patterns, the APD group was then divided into two subgroups: "criminal" and "noncriminal" APD groups. The day after the interview, after one night of fasting, blood was collected from the subjects between 7:00 a.m. and 9:00 a.m.. Thyroid function tests and other biochemical analyses related to the confounding variables were also administered. The study group and the control group were compared in terms of their aggression scores and thyroid hormone levels. The mean score of free T3 level in the criminal APD group was found to be significantly higher than that in the noncriminal APD group. APD subjects with higher free T3 levels also had higher aggression scores. In the noncriminal APD group, as serum free T3 and T4 levels increased, there was also an increment in the aggression scores. However, in the criminal APD group, there was no significant correlation between thyroid hormone levels and aggression. The findings of this study indicated that criminal and noncriminal APD groups actually show different properties.

  3. Effects of a Model Inducer, Phenobarbital, on Thyroid Hormone Glucuronidation in Rat Hepatocytes

    Science.gov (United States)

    In vivo, hepatic enzyme inducers such as phenobarbital (PB) decrease circulating thyroid hormone (TH) concentrations. This decrease in circulating TH occurs in part through extrathyroidal mechanisms. Specifically, through the induction of hepatic xenobiotic metabolizing enzymes...

  4. The use of konjac glucomannan to lower serum thyroid hormones in hyperthyroidism.

    Science.gov (United States)

    Azezli, Adil Dogan; Bayraktaroglu, Taner; Orhan, Yusuf

    2007-12-01

    Patients with hyperthyroidism occasionally need rapid restoration to the euthyroid state. In view of the increased enterohepatic circulation of thyroxine (T4) and triiodothyronine (T3) in thyrotoxicosis, and metabolic effects of konjac glucomannan in gastrointestinal system, we aimed to determine the activity of glucomannan in treatment of hyperthyroidism. A prospective, randomized, placebo-controlled, one-blind study design was used with newly diagnosed 48 hyperthyroid patients (30 patients with Graves' disease and 12 with multinodulary goitre). They were assigned to one of the following treatment groups: I) methimazole 2 x 10 mg, propranolol 2 x 20 mg, and glucomannan (Propol) 2 x 1.3 gr daily for two months; II) methimazole 2 x 10 mg, propranolol 2 x 20 mg, and placebo powder daily for two months. No differences were detected from the point of view of the baseline thyroid hormone levels between groups (p > 0.05). Further analyses revealed that the patients receiving glucomannan at the end of the second, fourth and sixth weeks of the study had significantly lower serum T3, T4, FT3 and FT4 levels than the patients who received placebo (p 0.05). At week 8, thyroid hormone levels were not shown any differences. The glucomannan-treated group had a more rapid decline in all four serum thyroid hormone levels than the placebo-treated group. We believe our preliminary results indicate that glucomannan may be a safe and easily tolerated adjunctive therapeutic agent in the treatment of thyrotoxicosis. This combination therapy seems most effect during first weeks of treatment of a hyperthyroid patient.

  5. Do Thyroid Disrupting Chemicals Influence Foetal Development during Pregnancy?

    Science.gov (United States)

    Hartoft-Nielsen, Marie-Louise; Boas, Malene; Bliddal, Sofie; Rasmussen, Åase Krogh; Main, Katharina; Feldt-Rasmussen, Ulla

    2011-01-01

    Maternal euthyroidism during pregnancy is crucial for normal development and, in particular, neurodevelopment of the foetus. Up to 3.5 percent of pregnant women suffer from hypothyroidism. Industrial use of various chemicals—endocrine disrupting chemicals (EDCs)—has been shown to cause almost constant exposure of humans with possible harmful influence on health and hormone regulation. EDCs may affect thyroid hormone homeostasis by different mechanisms, and though the effect of each chemical seems scarce, the added effects may cause inappropriate consequences on, for example, foetal neurodevelopment. This paper focuses on thyroid hormone influence on foetal development in relation to the chemicals suspected of thyroid disrupting properties with possible interactions with maternal thyroid homeostasis. Knowledge of the effects is expected to impact the general debate on the use of these chemicals. However, more studies are needed to elucidate the issue, since human studies are scarce. PMID:21918727

  6. Clinical significance of determination of serum thyroid hormones levels in patients with diabetic-2 nephrosis

    International Nuclear Information System (INIS)

    Zhou Feihua; Xu Haifeng; Zhou Runsuo; Sun Tao

    2008-01-01

    Objective: To explore the value of determination of serum thyroid hormones levels in patients with diabetic-2 nephrosis. Methods: Serum thyroid hormones (T 3 , T 4 , rT 3 , sTSH) levels in 98 patients with diabetic-2 nephrosis and 53 controls were measured with RIA. Results: Serum levels of T 3 was significantly higher in patients with diabetic-2 nephrosis than those in controls (P 4 , rT 3 , sTSH levels were not much different (P>0.05). Conclusion: Changes of serum T 3 levels in patients with critical illness were closely related to the severity of the disease process and were useful for outcome prediction. (authors)

  7. The study of thyroid-related hormones in Jinuo minority teenagers

    International Nuclear Information System (INIS)

    Yang Lei; Yuan Weihong; Xu Mian; Luo Zhihang; Du Juan; He Qin; Zhu Jiayou

    2003-01-01

    In order to study the difference of thyroid-related hormones between the Teenagers of Jinuo minority and those of Han nationality, 203 teenagers of Jinuo who are students of an ethnic middle school, Jinghong, took as the Jinuo group. This group was divided into three subgroups according to their age: 1)age from 13 to 14, 52 persons 2)age from 14 to 15, 91 persons 3)age from 15 to 16, 60 persons. Meanwhile, 100 teenagers of Han nationality lived in Kunming took as a control group, which also was divided into three subgroups 1)age from 13 to 14, 28 persons; 2)age from 14 to 15, 33 persons; 3)age from 15 to 16, 39 persons. The levels of T 3 T 4 and TSH in both groups were determined. The result showed no significant difference between two groups (P>0.05). From this result authors could conclude that though the Jinuo minority lives in the remote area and their nutrition and living conditions are poorer than the Han nationality, that do not contribute influence to their level of thyroid-related hormone

  8. Thyroid Diseases

    Science.gov (United States)

    ... beats. All of these activities are your body's metabolism. Thyroid problems include Goiter - enlargement of the thyroid gland Hyperthyroidism - when your thyroid gland makes more thyroid hormones ...

  9. External quality control assessment of thyroid related hormones in India. Final report for the period 1 December 1983 - 31 January 1988

    International Nuclear Information System (INIS)

    Shah, D.H.; Kumar, A.; Rajan, M.G.R.; Thakare, U.R.; Sharma, S.M.

    1989-11-01

    An external quality assessment scheme for thyroid related hormones was undertaken to assess the performance of various laboratories in India. The programme was conducted in two phases. The report summarizes the findings obtained on performances of the laboratories for radioimmunoassay of thyroid related hormones over the two phases. Figs and tabs

  10. Polybrominated diphenyl ether (PBDE)-induced alterations in vitamin A and thyroid hormone concentrations in the rat during lactation and early postnatal development

    International Nuclear Information System (INIS)

    Ellis-Hutchings, Robert G.; Cherr, Gary N.; Hanna, Lynn A.; Keen, Carl L.

    2006-01-01

    In experimental animals fed standard laboratory diets, penta-BDE mixtures can decrease circulating thyroid hormone and liver vitamin A concentrations. A substantial number of pregnant women and their children have marginal vitamin A status, potentially increasing their risk of adverse effects to penta-BDE exposure. The current study investigated the effects of maternal gestational and lactational penta-BDE exposure on thyroid hormone and vitamin A homeostasis in rats of sufficient vitamin A (VAS) or marginal vitamin A (VAM) status and their offspring. Dams were administered daily oral doses of 18 mg/kg DE-71 (a penta-BDE mixture) or a corn oil vehicle from gestation day 6 through lactation day (LD) 18. Thyroid hormone and vitamin A homeostasis were assessed in plasma and tissues of LD 19 dams and postnatal day (PND) 12, 18, and 31 pups. DE-71 exposure induced hepatomegaly in VAS and VAM pups at all timepoints and increased testes weights at PND 31. While liver vitamin A concentrations were low in DE-71 treated dams and pups, plasma retinol concentrations and plasma retinol binding protein levels were only low in VAM animals exposed to DE-71. DE-71 exposure lowered plasma thyroxine concentrations in VAS and VAM dams and pups. Plasma thyroid stimulating hormone concentrations were high in VAM dams exposed to DE-71, suggesting that marginal vitamin A status enhances the susceptibility to thyroid hormone axis disruption by DE-71. These results support the concept that marginal vitamin A status in pregnant women may increase the risk for PBDE-induced disruptions in vitamin A and thyroid hormone homeostasis

  11. Effect of the micronutrient iodine in thyroid carcinoma angiogenesis.

    Science.gov (United States)

    Daniell, Kayla; Nucera, Carmelo

    2016-12-20

    Iodide is a micronutrient essential for thyroid hormone production. The uptake and metabolism of iodide by thyrocytes is crucial to proper thyroid function. Iodide ions are drawn into the thyroid follicular cell via the sodium-iodide symporter (NIS) in the cell membrane and become integrated into tyrosyl residues to ultimately form thyroid hormones. We sought to learn how an abnormal concentration of iodide within thyrocyte can have significant effects on the thyroid, specifically the surrounding vascular network. Insufficient levels of iodide can lead to increased expression or activity of several pathways, including vascular endothelial growth factor (VEGF). The VEGF protein fuel vessel growth (angiogenesis) and therefore enhances the nutrients available to surrounding cells. Alternatively, normal/surplus iodide levels can have inhibitory effects on angiogenesis. Varying levels of iodide in the thyroid can influence thyroid carcinoma cell proliferation and angiogenesis via regulation of the hypoxia inducible factor-1 (HIF-1) and VEGF-dependent pathway. We have reviewed a number of studies to investigate how the effect of iodide on angiogenic and oxidative stress regulation can affect the viability of thyroid carcinoma cells. The various studies outlined give key insights to the role of iodide in thyroid follicles function and vascular growth, generally highlighting that insufficient levels of iodide stimulate pathways resulting in vascular growth, and viceversa normal/surplus iodide levels inhibit such pathways. Intriguingly, TSH and iodine levels differentially regulate the expression levels of angiogenic factors. All cells, including carcinoma cells, increase uptake of blood nutrients, meaning the vascular profile is influential to tumor growth and progression. Importantly, variation in the iodine concentrations also influence BRAF V600E -mediated oncogenic activity and might deregulate tumor proliferation. Although the mechanisms are not well eluted, iodine

  12. Influence of thyroid in nervous system growth.

    Science.gov (United States)

    Mussa, G C; Mussa, F; Bretto, R; Zambelli, M C; Silvestro, L

    2001-08-01

    Nervous system growth and differentiation are closely correlated with the presence of iodine and thyroid hormones in initial development stages. In the human species, encephalon maturation during the first quarter of pregnancy is affected according to recent studies by the transplacenta passage of maternal thyroid hormones while it depends on initial iodiothyronin secretion by the foetal gland after the 12th week of pregnancy. Thyroid hormone deficiency during nervous system development causes altered noble nervous cells, such as the pyramidal cortical and Purkinje cells, during glial cell proliferation and differentiation alike. Neurons present cell hypoplasia with reduced axon count, dendritic branching, synaptic spikes and interneuron connections. Oligodendrocytes decrease in number and average myelin content consequently drops. Biochemical studies on hypothyroid rats have demonstrated alterations to neuron intraplasmatic microtubule content and organisation, changed mitochondria number and arrangement and anomalies in T3 nuclear and citoplasmatic receptor maturation. Alterations to microtubules are probably responsible for involvement of the axon-dendrite system, and are the consequence of deficient thyroid hormone action on the mitochondria, the mitochondria enzymes and proteins associated with microtubules. Nuclear and citoplasmatic receptors have been identified and gene clonation studies have shown two families of nuclear receptors that include several sub-groups in their turn. A complex scheme of temporal and spatial expression of these receptors exists, so they probably contribute with one complementary function, although their physiological role differs. The action of thyroid hormones occurs by changing cell protein levels because of their regulation at the transcriptional or post-transcriptional level. Genes submitted to thyroid hormone control are either expressed by oligodendrytes, which are myelin protein coders or glial differentiation mediators, or

  13. Thyroid hormone participates in the regulation of neural stem cells and oligodendrocyte precursor cells in the central nervous system of adult rat.

    Science.gov (United States)

    Fernandez, M; Pirondi, S; Manservigi, M; Giardino, L; Calzà, L

    2004-10-01

    Oligodendrocyte development and myelination are under thyroid hormone control. In this study we analysed the effects of chronic manipulation of thyroid status on the expression of a wide spectrum of oligodendrocyte precursor cells (OPCs) markers and myelin basic protein (MBP) in the subventricular zone (SVZ), olfactory bulb and optic nerve, and on neural stem cell (NSC) lineage in adult rats. Hypo- and hyperthyroidism were induced in male rats, by propyl-thio-uracil (PTU) and L-thyroxin (T4) treatment, respectively. Hypothyroidism increased and hyperthyroidism downregulated proliferation in the SVZ and olfactory bulb (Ki67 immunohistochemistry and Western blotting, bromodeoxyuridine uptake). Platelet-derived growth factor receptor alpha (PDGFalpha-R) and MBP mRNA levels decreased in the optic nerve of hypothyroid rats; the same also occurred at the level of MBP protein. Hyperthyroidism slightly upregulates selected markers such as NG2 in the olfactory bulb. The lineage of cells derived from primary cultures of NSC prepared from the forebrain of adult hypo- and hyperthyroid also differs from those derived from control animals. Although no difference of in vitro proliferation of NSCs was observed in the presence of epidermal growth factor, maturation of oligodendrocytes (defined by process number and length) was enhanced in hyperthyroidism, suggesting a more mature state than in control animals. This difference was even greater when compared with the hypothyroid group, the morphology of which suggested a delay in differentiation. These results indicate that thyroid hormone affects NSC and OPC proliferation and maturation also in adulthood.

  14. Kcne2 deletion uncovers its crucial role in thyroid hormone biosynthesis

    Science.gov (United States)

    Roepke, Torsten K.; King, Elizabeth C.; Reyna-Neyra, Andrea; Paroder, Monika; Purtell, Kerry; Koba, Wade; Fine, Eugene; Lerner, Daniel J.; Carrasco, Nancy; Abbott, Geoffrey W.

    2009-01-01

    Thyroid dysfunction affects 1–4% of the population worldwide, causing defects including neurodevelopmental disorders, dwarfism and cardiac arrhythmia. Here, we show that KCNQ1 and KCNE2 form a TSH-stimulated, constitutively-active, thyrocyte K+ channel required for normal thyroid hormone biosynthesis. Targeted disruption of Kcne2 impaired thyroid iodide accumulation up to 8-fold, impaired maternal milk ejection and halved milk T4 content, causing hypothyroidism, 50% reduced litter size, dwarfism, alopecia, goiter, and cardiac abnormalities including hypertrophy, fibrosis, and reduced fractional shortening. The alopecia, dwarfism and cardiac abnormalities were alleviated by T3/T4 administration to pups, by supplementing dams with T4 pre- and postpartum, or by pre-weaning surrogacy with Kcne2+/+ dams; conversely these symptoms were elicited in Kcne2+/+ pups by surrogacy with Kcne2−/− dams. The data identify a critical thyrocyte K+ channel, provide a possible novel therapeutic avenue for thyroid disorders, and predict an endocrine component to some previously-identified KCNE2- and KCNQ1-linked human cardiac arrhythmias. PMID:19767733

  15. MOK, a pharmacopuncture medicine, regulates thyroid dysfunction in L-thyroxin-induced hyperthyroidism in rats through the regulation of oxidation and the TRPV1 ion channel.

    Science.gov (United States)

    Hwang, Ji Hye; Kang, Seok Yong; Kang, An Na; Jung, Hyo Won; Jung, Chul; Jeong, Jin-Ho; Park, Yong-Ki

    2017-12-15

    In this study, we evaluated the therapeutic effect of MOK, a pharmacopuncture medicine, on thyroid dysfunction in L-thyroxin (LT4)-induced hyperthyroidism rats. The experimental hyperthyroidism model was prepared by the intraperitoneal injection of LT4 (0.5 mg/kg) once daily for 2 weeks in SD rats. MOK extract was injected at doses of 0.3 or 3 mg/kg on acupuncture points in the thyroid glands of LT4-induced hypothyroidism rats once a day for 2 weeks. The body temperature, body weight, and food/water intake were measured once a week for 2 weeks. The levels of thyroid hormones, total cholesterol, LDL-cholesterol, GOT, and GPT were measured in the sera of rats using ELISA and an automatic blood analyzer. The histological changes of thyroid tissues were observed by H&E staining. The expression of thermo-regulating protein, TRPV1 was determined by western blot in dorsal root ganglion (DRG) and brain tissues. We also measured the contents of GSH in the liver and antioxidant enzymes, SOD, and catalase in the liver, heart, and brain tissues by enzyme-based assay and Western blot, respectively. The acupuncture of MOK extract on the thyroid gland of LT4-induced hyperthyroidism rats significantly decreased the body temperature, and did not change body weight and food and water intakes. MOK acupuncture significantly increased the level of TSH, and decreased the levels of T3 and T4 in hyperthyroidism rats. The expression of TRPV1 was inhibited in both DRG and brain tissues after MOK acupuncture, and the levels of GOT, GPT, total cholesterol, and LDL-cholesterol were also decreased. MOK acupuncture also inhibited the pathological feature with follicular lining epithelial thicknesses and increased follicular colloid depositions in the thyroid glands of hypothyroidism. MOK acupuncture significantly increased hepatic GSH levels and decreased the expression of SOD and catalase in the liver, heart, and brain tissues of hyperthyroidism rats. These results suggest that the

  16. Modifications of thyroid hormones secretion and production in newborn rats from hyperthyroic dams

    International Nuclear Information System (INIS)

    Silveira, M.F.G.; Neves, E.S.S.; Neves, S.R.S.; Catanho, M.T.J.A.

    1997-01-01

    The onset of fetal thyroid function occurs about 17-18 days after conception in the rat. The maternal hyperthyroidism which occurs during gestation provokes alterations in the rat after its birth; due to this alterations, we decided to analyze the metabolic and hormonal modification in the newborn rats. The hyperthyroidism was induced in normal dams, which were being trated for 2 days with T4 2mg (thyroxine per 100g body wt/day) before mating. Another dam group which was submitted to an inducement of hyperthyroidism maintained the treatment with T4 and six day after gestation were being treated for 9 days. It was seen that the rat which was born from hyperthyroic dams suffered alterations on its T4 and T3 hormone levels concerning the days 10, 20 and 30 after birth. T4 e T3 were performed with Immu chem cooted tube - I 125 RIA KIT .The administration of T4 affected the fetal thyroid function gland to, causing a decrease of both T4 and T3 levels, as was also modifications on their weight and size, even after the birth, indicating that the maternal hyperthyroidism influences on the post-natal life of the rat. The growth is affected throught post-natal life by thyroid hormones, which have a facilitatory influence on GH economy, as opposed to the inhibitory effects on TSH economy. (author). 12 refs., 4 figs

  17. Thyrocyte-specific Gq/G11 deficiency impairs thyroid function and prevents goiter development.

    Science.gov (United States)

    Kero, Jukka; Ahmed, Kashan; Wettschureck, Nina; Tunaru, Sorin; Wintermantel, Tim; Greiner, Erich; Schütz, Günther; Offermanns, Stefan

    2007-09-01

    The function of the adult thyroid is regulated by thyroid-stimulating hormone (TSH), which acts through a G protein-coupled receptor. Overactivation of the TSH receptor results in hyperthyroidism and goiter. The Gs-mediated stimulation of adenylyl cyclase-dependent cAMP formation has been regarded as the principal intracellular signaling mechanism mediating the action of TSH. Here we show that the Gq/G11-mediated signaling pathway plays an unexpected and essential role in the regulation of thyroid function. Mice lacking the alpha subunits of Gq and G11 specifically in thyroid epithelial cells showed severely reduced iodine organification and thyroid hormone secretion in response to TSH, and many developed hypothyroidism within months after birth. In addition, thyrocyte-specific Galphaq/Galpha11-deficient mice lacked the normal proliferative thyroid response to TSH or goitrogenic diet, indicating an essential role of this pathway in the adaptive growth of the thyroid gland. Our data suggest that Gq/G11 and their downstream effectors are promising targets to interfere with increased thyroid function and growth.

  18. Adult Hippocampal Neurogenesis is Impaired by Transient and Moderate Developmental Thyroid Hormone Disruption

    Science.gov (United States)

    Severe thyroid hormone (TH) deprivation during development impairs neurogenesis throughout the brain. The hippocampus also maintains a capacity for neurogenesis throughout life which is reduced in adult-onset hypothyroidism. This study examined hippocampal volume in the neonate a...

  19. Multiplex Immunoassay Profiling of Hormones Involved in Metabolic Regulation.

    Science.gov (United States)

    Stephen, Laurie; Guest, Paul C

    2018-01-01

    Multiplex immunoassays are used for rapid profiling of biomarker proteins and small molecules in biological fluids. The advantages over single immunoassays include lower sample consumption, cost, and labor. This chapter details a protocol to develop a 5-plex assay for glucagon-like peptide 1, growth hormone, insulin, leptin, and thyroid-stimulating hormone on the Luminex ® platform. The results of the analysis of insulin in normal control subjects are given due to the important role of this hormone in nutritional programming diseases.

  20. Epigenetic involvement of Alien/ESET complex in thyroid hormone-mediated repression of E2F1 gene expression and cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wei, E-mail: hongwei@tijmu.edu.cn [Department of Immunology, Tianjin Medical University, 300070 Tianjin (China); College of Basic Medicine, Tianjin Medical University, 300070 Tianjin (China); Li, Jinru; Wang, Bo [College of Basic Medicine, Tianjin Medical University, 300070 Tianjin (China); Chen, Linfeng [Department of Medical Oncology, Harvard Medical School, Dana Farber Cancer Institute, Boston, 02115 MA (United States); Niu, Wenyan; Yao, Zhi [Department of Immunology, Tianjin Medical University, 300070 Tianjin (China); Baniahmad, Aria, E-mail: aban@mti.uni-jena.de [Institute for Human Genetics, Jena University Hospital, 07740 Jena (Germany)

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer Corepressor Alien interacts with histone methyltransferase ESET in vivo. Black-Right-Pointing-Pointer Alien/ESET complex is recruited to nTRE of T3-responsive gene by liganded TR{beta}1. Black-Right-Pointing-Pointer ESET-mediated H3K9 methylation is required for liganded TR{beta}1-repressed transcription. Black-Right-Pointing-Pointer ESET is involved in T3-repressed G1/S phase transition and proliferation. -- Abstract: The ligand-bound thyroid hormone receptor (TR) is known to repress via a negative TRE (nTRE) the expression of E2F1, a key transcription factor that controls the G1/S phase transition. Alien has been identified as a novel interacting factor of E2F1 and acts as a corepressor of E2F1. The detailed molecular mechanism by which Alien inhibits E2F1 gene expression remains unclear. Here, we report that the histone H3 lysine 9 (H3K9) methyltransferase (HMT) ESET is an integral component of the corepressor Alien complex and the Alien/ESET complex is recruited to both sites, the E2F1 and the nTRE site of the E2F1 gene while the recruitment to the negative thyroid hormone response element (nTRE) is induced by the ligand-bound TR{beta}1 within the E2F1 gene promoter. We show that, overexpression of ESET promotes, whereas knockdown of ESET releases, the inhibition of TR{beta}1-regulated gene transcription upon T3 stimulation; and H3K9 methylation is required for TR{beta}1-repressed transcription. Furthermore, depletion of ESET impairs thyroid hormone-repressed proliferation as well as the G1/S transition of the cell cycle. Taken together, our data indicate that ESET is involved in TR{beta}1-mediated transcription repression and provide a molecular basis of thyroid hormone-induced repression of proliferation.

  1. Sick leave for follow-up control in thyroid cancer patients: comparison between stimulation with Thyrogen and thyroid hormone withdrawal.

    Science.gov (United States)

    Borget, I; Corone, C; Nocaudie, M; Allyn, M; Iacobelli, S; Schlumberger, M; De Pouvourville, G

    2007-05-01

    The clinical benefits of recombinant human thyroid-stimulating hormone (rhTSH; Thyrogen) are well established as an alternative stimulation procedure to thyroid hormone withdrawal in the diagnostic follow-up of thyroid cancer patients. By avoiding periods of hypothyroidism, patients do not suffer from a decreased quality of life and keep their ability to work. This study compared the frequency, the duration and the cost of sick leave for follow-up control between rhTSH and withdrawal. The study population consisted of patients with thyroid carcinoma first treated by thyroidectomy and radioiodine ablation. Patients were recruited at their control visit between October 2004 and May 2006 in three hospitals, both prospectively and retrospectively. Collection data consisted of patient information, job characteristics and duration of sick leave during the month before and the month after control. The valuation of sick leave used the friction cost method. Among the 306 patients included, 292 (95%) completed the entire questionnaire. The mean age was 46.7 years. Among the 194 active patients, patients treated with rhTSH, when compared with patients treated by withdrawal, were less likely to require sick leave (11 vs 33%; P=0.001). The mean duration of sick leave was shorter (3.1 vs 11.2 days; P=0.002) and indirect costs due to absenteeism accounted for 454 Euro +/- 1673 vs 1537 Euro +/- 2899 for withdrawal stimulation. For active patients, rhTSH treatment reduced the length and the cost of sick leave by 8.1 days and 1083 Euro per control respectively, when compared with withdrawal treatment.

  2. Effects of Thyroid Hormone on Left Ventricular Volume and Function in Hyperthyroidism

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Koh, Chang Soon

    1983-01-01

    The purpose of this study is to investigate the effects of thyroid hormone on the left ventricular (LV) volume and function in man with untreated hyperthyroidism and to determine the effects of successful therapy for thyrotoxicosis on the ventricular pathophysiology. In the present study, equilibrium ralhianuclide cardiac angiography was performed and LV volume index, ejection phase indexes of LV performance, serum thyroid hormone levels and other hemodynamic parameters were measured in 28 normal subjects and 39 patients with hyperthyroidism before treatment and again every 4 weeks for the first 2 months after the initiation of effective therapy. The result obtained were as follows; 1) In the untreated hyperthyroid state heart rate, blood volume, cardiac index and stroke volume index (97±14 beats/min, 73.5±11.8 ml/kg, 6.9±1.4 l/min/m2 and 77.6±13.8 ml/m2, respectively) were increased significantly compared to those in normal control (74±12 beats/min, 65.6±14.8 ml/kg, 3.8±1.2 l/min/m2 and 56.6±13.2 ml/m2 respectively). (Mean±SD). 2) There was a significant increase in LV end-diastolic volume index in patients with hyperthyroidism (30.5±7.5 for hyperthyroid group compared to a normal control of 22.2±6.5; P<0.001), whereas end-systolic volume index remained unchanged 9.6±3.6 and 8.8±3.3 respectively. 3) In patients with hyperthyroidism, LV ejection fraction was 70.0±5.6%, fractional shortening 32.9±5.1%, mean velocity of circumferential fiber shortening (mean Vcf) 1.34±0.31 circ/sec and maximum ejection rate 3.47±0.80. All the ejection phase indexes were significantly greater than those in normal control (65.2±5.7%, 28.8±3.2%, 0.88±0.37 circ/sec and 2.27±0.50, respectively; p<0.001). 4) Effective therapy produced significant decrease in all the values of serum thyroid hormone concenrations (p<0.001), hemodynamic parameters (p<0.001), end-diastolic volume index (p<0.01) and ejection phase indexes of LV contractility in patients with hyperthyroidism

  3. Thyroid hormone regulation of Sirtuin 1 expression and implications to integrated responses in fasted mice.

    Science.gov (United States)

    Cordeiro, Aline; de Souza, Luana Lopes; Oliveira, Lorraine Soares; Faustino, Larissa Costa; Santiago, Letícia Aragão; Bloise, Flavia Fonseca; Ortiga-Carvalho, Tania Maria; Almeida, Norma Aparecida Dos Santos; Pazos-Moura, Carmen Cabanelas

    2013-02-01

    Sirtuin 1 (SIRT1), a NAD(+)-dependent deacetylase, has been connected to beneficial effects elicited by calorie restriction. Physiological adaptation to starvation requires higher activity of SIRT1 and also the suppression of thyroid hormone (TH) action to achieve energy conservation. Here, we tested the hypothesis that those two events are correlated and that TH may be a regulator of SIRT1 expression. Forty-eight-hour fasting mice exhibited reduced serum TH and increased SIRT1 protein content in liver and brown adipose tissue (BAT), and physiological thyroxine replacement prevented or attenuated the increment of SIRT1 in liver and BAT of fasted mice. Hypothyroid mice exhibited increased liver SIRT1 protein, while hyperthyroid ones showed decreased SIRT1 in liver and BAT. In the liver, decreased protein is accompanied by reduced SIRT1 activity and no alteration in its mRNA. Hyperthyroid and hypothyroid mice exhibited increases and decreases in food intake and body weight gain respectively. Food-restricted hyperthyroid animals (pair-fed to euthyroid group) exhibited liver and BAT SIRT1 protein levels intermediary between euthyroid and hyperthyroid mice fed ad libitum. Mice with TH resistance at the liver presented increased hepatic SIRT1 protein and activity, with no alteration in Sirt1 mRNA. These results suggest that TH decreases SIRT1 protein, directly and indirectly, via food ingestion control and, in the liver, this reduction involves TRβ. The SIRT1 reduction induced by TH has important implication to integrated metabolic responses to fasting, as the increase in SIRT1 protein requires the fasting-associated suppression of TH serum levels.

  4. Thyroid and Cortisol hormones in Attention Deficit Hyperactivity Disorder: A case-control study.

    Science.gov (United States)

    Kuppili, Pooja Patnaik; Pattanayak, Raman Deep; Sagar, Rajesh; Mehta, Manju; Vivekanandhan, S

    2017-08-01

    There is paucity of research in the putative role of hormonal biomarkers in Attention Deficit Hyperactivity Disorder (ADHD). The current study aimed to analyze the clinical profile, socio-demographic status, co-morbidity, hormonal biomarkers namely Thyroid hormones and Cortisol in children with ADHD and compare them with healthy controls and to explore the association of the hormonal biomarkers with severity of ADHD. Thirty children with DSM-IV TR diagnosis of ADHD were assessed using semi structured proforma, Conners' Parent Rating Scale revised short (CPRS - R: S) , Mini international neuropsychiatric interview for children and adolescents and Childrens' Global Assessment Scale as well as serum levels of total Triiodothyronine (T3) ,total Thyroxine (T4) , Thyroid Stimulating Hormone (TSH) and Cortisol using chemiluminescent immunometric assay and compared with 30 age- and gender -matched controls. The typical profile of cases of ADHD was of a male with mean age of 9.47 years (S.D=2.43) belonging to Hyperactive subtype of ADHD. Serum T4 was significantly lower in cases compared to controls. No significant difference was found in serum T3, TSH and Cortisol levels. No significant correlation between the CPRS : R-S scores and the hormonal biomarkers. There is need for exploration of Serum T4 as putative biomarker for ADHD with replication in future studies. It may also be important to report the negative finding of Cortisol as a biomarker of ADHD in the context of effective utilization of resources for research with special relevance to resource deficit developing countries. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Myopathy in hyperthyroidism as a consequence of rapid reduction of thyroid hormone: A case report.

    Science.gov (United States)

    Li, Qianrui; Liu, Yuping; Zhang, Qianying; Tian, Haoming; Li, Jianwei; Li, Sheyu

    2017-07-01

    Myalgia and elevated creatine kinase (CK) are occasionally observed during the treatment of hyperthyroid patients. Relative hypothyroidism resulted from rapid thyroid hormone reduction had been promoted as a plausible cause of these myopathic changes, however rarely reported. We hereby presented a 20-year-old female with Grave's disease, who developed myopathy and elevated CK during rapid correction of thyroid hormone. Relative hypothyroidism-induced myopathy. Antithyroid drug (ATD) dosage was reduced without levothyroxine replacement. The muscular symptoms were recovered with CK level returned to normal after adoption of the euthyroid status. Differentiation of relative hypothyroidism from other causes of myopathy, especially with the effect of ATD, is important for clinical practice, although difficult in many cases.

  6. Challenges in interpretation of thyroid function tests in pregnant women with autoimmune thyroid disease

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, Ulla; Bliddal, Sofie; Rasmussen, Åse Krogh

    2011-01-01

    Physiological changes during gestation are important to be aware of in measurement and interpretation of thyroid function tests in women with autoimmune thyroid diseases. Thyroid autoimmune activity is decreasing in pregnancy. Measurement of serum TSH is the first-line screening variable...... for thyroid dysfunction also in pregnancy. However, using serum TSH for control of treatment of maternal thyroid autoimmunity infers a risk for compromised foetal development. Peripheral thyroid hormone values are highly different among laboratories, and there is a need for laboratory-specific gestational age......-related reference ranges. Equally important, the intraindividual variability of the thyroid hormone measurements is much narrower than the interindividual variation (reflecting the reference interval). The best laboratory assessment of thyroid function is a free thyroid hormone estimate combined with TSH...

  7. Thyroid Problems

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Thyroid Problems Font size A A A Print Share Glossary Basic ... enough thyroid hormone, usually of the thyroxine (T4) type of hormone. Your T4 levels can drop temporarily ...

  8. Studies on the relationship between thyroid hormones, ovarian hormones, GnRH and reproductive performance of egyptian buffaloes

    International Nuclear Information System (INIS)

    Farghaly, H.A.M.

    1992-01-01

    this study was carried out in the experimental farm of animal production department, faculty of agriculture, cairo university. hormonal analysis were performed in the laboratories of animal physiology unit, radiobiology department, nuclear research center, atomic energy authority (radiobiol. Dept., NRC, AEA). The aim of the study was to investigate the following : 1- post-partum reproductive activity of egyptian buffaloes and the factors affecting the resumption of ovarian activity after calving , with particular reference to the patterns of thyroid hormones (T 4 and T 3 ) and progesterone hormone.2- the effectiveness of using GnRH treatment on inducing ovarian activity after calving. 3- the effect of goitrogen administration (thiouracil) on ovarian activity during post-partum and on the response of buffaloes to GnRH treatment and their reproductive patterns

  9. Status of calcium regulating hormonal systems in delayed period in persons exposed to occupational exposure of low doses of ionizing radiations

    International Nuclear Information System (INIS)

    Dospolova, Zh.G.; Abylaev, Zh.A.

    1997-01-01

    Purpose of study is consideration of endocrine system participation in development of calcium exchange disorders in persons exposed to action of low dose radiation . By radio- immune method in blood serum of 150 liquidators of Chernobyl accident consequences the concentration the following hormones were determined: parathormone, T 3 , T 4 , TSH, cortisol, ACTH, testosteron, insulin. Content of these hormones have been studied in according to following radiation factors: value of absorbed doses of external irradiation, degree of radioactive contamination of zone and exposition duration. It was determined, that basically dishormone disorders development have been concerned with parathormone, cortisol, hormones of thyroid axis, and in some cases to ACTH and insulin. Liquidators' frequencies of normal and changed concentration of calcium regulating hormones are sited in tabular form. It was established, that examined persons in result hormone disorders have of decrease functions of pituitary glands (76.78 %), pancreas (55 %), thyroid gland (24.31 %) and sex glands (19.23 %) and simultaneously cases of increase functions of parathyroid gland (58.2 %), adrenal glands (52.32 %) and adeno-pituitary glands (17.39). It is concluded, that inter hormonal correlation disorders are accompanying with morphologic and functional futures of secretory activity changes

  10. IL-1β a potential factor for discriminating between thyroid carcinoma and atrophic thyroiditis.

    Science.gov (United States)

    Kammoun-Krichen, Maha; Bougacha-Elleuch, Noura; Mnif, Mouna; Bougacha, Fadia; Charffedine, Ilhem; Rebuffat, Sandra; Rebai, Ahmed; Glasson, Emilie; Abid, Mohamed; Ayadi, Fatma; Péraldi-Roux, Sylvie; Ayadi, Hammadi

    2012-01-01

    Interactions between cytokines and others soluble factors (hormones, antibodies...) can play an important role in the development of thyroid pathogenesis. The purpose of the present study was to examine the possible correlation between serum cytokine concentrations, thyroid hormones (FT4 and TSH) and auto-antibodies (Tg and TPO), and their usefulness in discriminating between different thyroid conditions. In this study, we investigated serum from 115 patients affected with a variety of thyroid conditions (44 Graves' disease, 17 Hashimoto's thyroiditis, 11 atrophic thyroiditis, 28 thyroid nodular goitre and 15 papillary thyroid cancer), and 30 controls. Levels of 17 cytokines in serum samples were measured simultaneously using a multiplexed human cytokine assay. Thyroid hormones and auto-antibodies were measured using ELISA. Our study showed that IL-1β serum concentrations allow the discrimination between atrophic thyroiditis and papillary thyroid cancer groups (p = 0.027).

  11. Effects of PBDE-47 on thyroid and steroid hormone status in juvenile turbot (Schophtalamus maximus)

    Energy Technology Data Exchange (ETDEWEB)

    Jenssen, G.; Tyrhaug, I.B.; Sormo, E.G. [Dept. of Biology, Norwegian Univ. of Science and Technology, Trondheim (Norway); Andersen, O.K. [Rogaland Research Akvamiljo, Mekjarvik (Norway)

    2004-09-15

    Many of the brominated flame retardant (BFR) chemicals, and particularly polybrominated diphenyl ethers (PBDEs), has become of increasing concern to scientists over the past decade. Many of the PBDEs are persistent and lipophilic and have been shown to bioaccumulate. The levels of PBDEs in biota seem to be increasing, and several trends, including in humans, indicate that this increase may be rapid1. In general, BFRs have a low acute toxicity, but there is concern about their long-term toxic effects. Exposure studies have revealed a range of subtle biochemical, cellular and physiological effects following low-dose exposure, and many BFRs have been reported to have endocrine disruptive properties. Thus, there is concern about their potential to affect organisms and populations. Thyroid hormones (THs) play an important role in organism's development, metabolism, growth and behavior. Polyhalogenated aromatic hydrocarbons (PHAHs) including BFRs may affect the thyroid system through several mechanisms. They may directly affect the thyroid gland function, the peripheral metabolism of THs and/or the binding of THs to plasma transport proteins. Effects of PHAHs on TH homeostasis have been documented in a number of species, including fish. Du to its persistence against degradation PBDE-47 is among the most abundant PBDE congener in biota, and there is a great concern about its ecotoxicological effects on organisms and populations. The aim of the present study was to examine if PBDE-47 may affect levels of circulating steroid and thyroid hormones in juvenile turbot (Scophtalamus maximus). The turbot is a benthic living flatfish that can be exposed to PHAHs via the sediment living organisms. Thus, plasma levels of T, E, and the thyroid hormones thyroxine (T4) and triiodothyronine (T3) were determined in juvenile turbot that had been continuously exposed to PBDE-47 via water for 3 weeks.

  12. Thyroid and the Heart

    Directory of Open Access Journals (Sweden)

    A Karas

    2009-09-01

    Full Text Available The cardiovascular signs and symptoms of thyroid disease are some of the most clinically relevant findings that accompany both hyperthyroidism and hypothyroidism. On the basis of the understanding of the mechanisms of thyroid hormone action on the heart and cardiovascular system, it is possible to explain the changes in cardiac output, cardiac contractility, blood pressure and rhythm disturbances that result from thyroid dysfunction. In the present review will integrate what is known about the mechanisms of thyroid hormone action on the heart and the alterations in thyroid hormone metabolism that accompany chronic congestive heart failure.

  13. Thyroid hormone concentrations differ between donkeys and horses.

    Science.gov (United States)

    Mendoza, F J; Perez-Ecija, R A; Toribio, R E; Estepa, J C

    2013-03-01

    Reference intervals for thyroid hormones (TH) concentrations have not been previously established for donkeys, leading to potential misdiagnosis of thyroid disease. To determine the normal values of TH in healthy adult donkeys and compare them to TH values from healthy adult horses. Thirty-eight healthy Andalusian donkeys and 19 healthy Andalusian horses from 2 different farms were used. Donkeys were divided into 3 age groups: 11 years and into 2 gender groups. Serum concentrations of fT3, tT3, rT3, fT4 and tT4 were quantified by radioimmunoassay. All blood samples were collected the same day in the morning. None of the animals had received any treatment for 30 days prior to sampling or had any history of disease. Both farms were in close proximity and under similar management. Differences between groups were determined using a one-way ANOVA analysis followed by Fisher's LSD test. Pdonkeys than in horses (PDonkeys donkeys >5 years (Pdonkeys (>11 years) had lower serum fT3 and tT3 concentrations than younger donkeys' groups (donkeys and horses. Establishing species-specific TH reference ranges is important when evaluating clinicopathologic data in equids in order to avoid the misdiagnosis of thyroid gland dysfunction. Further studies to elucidate the physiological mechanisms leading to these differences are warranted. © 2012 EVJ Ltd.

  14. Cardioprotective effects of lipoic acid, quercetin and resveratrol on oxidative stress related to thyroid hormone alterations in long-term obesity.

    Science.gov (United States)

    Cheserek, Maureen Jepkorir; Wu, Guirong; Li, Longnan; Li, Lirong; Karangwa, Eric; Shi, Yonghui; Le, Guowei

    2016-07-01

    This study investigated possible mechanisms for cardioprotective effects of lipoic acid (LA), quercetin (Q) and resveratrol (R) on oxidative stress related to thyroid hormone alterations in long-term obesity. Female C57BL/6 mice were fed on high-fat diet (HFD), HFD+LA, HFD+R, HFD+Q and normal diet for 26weeks. Body weight, blood pressure, thyroid hormones, oxidative stress markers, angiotensin converting enzyme (ACE), nitric oxide synthase (NOS) and ion pump activities were measured, and expression of cardiac genes was analyzed by real-time polymerase chain reaction. HFD induced marked increase (Pstress, while plasma triidothyronine levels reduced. ACE activity increased (Pobesity thereby restoring plasma thyroid hormone levels and attenuating oxidative stress in the heart and thus may have therapeutic potential in heart diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The effects of whole-body irradiation on the serum levels and kinetics of thyroid hormones in rats

    International Nuclear Information System (INIS)

    Gray, W.M.

    1980-01-01

    The effects of a single whole-body dose of X-rays on the serum levels and kinetics of thyroid hormones in rats were studied. The influence of radiation-induced anorexia was monitored by using pair fed control groups. A dose of 800 rad caused a reduction in T 4 levels and 750 rad had a similar effect on T 3 ; in each case the control group showed a smaller reduction. The kinetic results indicated that, in the control groups, the early reduction in hormone concentrations was caused by decreased production, whereas, in the irradiated groups, it was caused by a change in the distribution of the hormone; however the continuing reduction in hormone levels in the irradiated rats appeared to result from decreased production. The results suggest that the thyroid system may play an active part in the early metabolic changes which follow whole-body irradiation. (author)

  16. Thyroid dysfunction in pregnancy

    Directory of Open Access Journals (Sweden)

    El Baba KA

    2012-03-01

    Full Text Available Khalid A El Baba1, Sami T Azar21Department of Internal Medicine, Division of Endocrinology, Bahrain Specialist Hospital, Manama, Bahrain; 2Department of Internal Medicine, Division of Endocrinology, American University of Beirut-Medical Center, New York, NY, USAAbstract: Timely treatment of thyroid disease during pregnancy is important in preventing adverse maternal and fetal outcomes. Thyroid abnormalities are very often subclinical in nature and not easily recognized without specific screening programs. Even mild maternal thyroid hormone deficiency may lead to neurodevelopment complications in the fetus. The main diagnostic indicator of thyroid disease is the measurement of serum thyroid-stimulating hormone and free thyroxine levels. Availability of gestation-age-specific thyroid-stimulating hormone thresholds is an important aid in the accurate diagnosis and treatment of thyroid dysfunction. Pregnancy-specific free thyroxine thresholds not presently available are also required. Large-scale intervention trials are urgently needed to assess the efficacy of preconception or early pregnancy screening for thyroid disorders. Accurate interpretation of both antepartum and postpartum levels of thyroid hormones is important in preventing pregnancy-related complication secondary to thyroid dysfunction. This article sheds light on the best ways of management of thyroid dysfunction during pregnancy in order to prevent any possible maternal or fetal complication.Keywords: TSH, HCG, TBG

  17. Thyroid hormones and electrocardiographic parameters: findings from the third national health and nutrition examination survey.

    Directory of Open Access Journals (Sweden)

    Yiyi Zhang

    Full Text Available Altered thyroid status exerts a major effect on the heart. Individuals with hypo- or hyperthyroidism showed various changes in electrocardiograms. However, little is known about how variations in thyroid hormone levels within the normal range affect electrical activities of the heart in the general population.We conducted a cross-sectional analysis of 5,990 men and women from the Third National Health and Nutrition Examination Survey. Serum total T4 was measured by immunoassay and TSH was measured by chemiluminescent assay. We categorized T4 and TSH into 7 groups with cut-offs at the 5(th, 20(th, 40(th, 60(th, 80(th, and 95(th percentiles of the weighted population distribution. Electrocardiographic parameters were measured from the standard 12-lead electrocardiogram. We found a positive linear association between serum total T4 level and heart rate in men, and a U-shape association between T4 and PR interval in men and women. TSH level was positively associated with QRS interval in men, while a U-shape association between TSH and QRS was observed in women. No clear graded association between thyroid hormones and corrected QT or JT was found, except that men in the highest category of T4 levels appeared to have longer corrected QT and JT, and men in the lowest category of T4 appeared to have shorter corrected QT and JT.Variation in thyroid hormone levels in the general population, even within the normal range, was associated with various ECG changes.

  18. The effects of subchronic acrylamide exposure on gene expression, neurochemistry, hormones, and histopathology in the hypothalamus-pituitary-thyroid axis of male Fischer 344 rats

    International Nuclear Information System (INIS)

    Bowyer, J.F.; Latendresse, J.R.; Delongchamp, R.R.; Muskhelishvili, L.; Warbritton, A.R.; Thomas, M.; Tareke, E.; McDaniel, L.P.; Doerge, D.R.

    2008-01-01

    Acrylamide (AA) is an important industrial chemical that is neurotoxic in rodents and humans and carcinogenic in rodents. The observation of cancer in endocrine-responsive tissues in Fischer 344 rats has prompted hypotheses of hormonal dysregulation, as opposed to DNA damage, as the mechanism for tumor induction by AA. The current investigation examines possible evidence for disruption of the hypothalamic-pituitary-thyroid axis from 14 days of repeated exposure of male Fischer 344 rats to doses of AA that range from one that is carcinogenic after lifetime exposure (2.5 mg/kg/d), an intermediate dose (10 mg/kg/d), and a high dose (50 mg/kg/d) that is neurotoxic for this exposure time. The endpoints selected include: serum levels of thyroid and pituitary hormones; target tissue expression of genes involved in hormone synthesis, release, and receptors; neurotransmitters in the CNS that affect hormone homeostasis; and histopathological evaluation of target tissues. These studies showed virtually no evidence for systematic alteration of the hypothalamic-pituitary-thyroid axis and do not support hormone dysregulation as a plausible mechanism for AA-induced thyroid cancer in the Fischer 344 rat. Specifically, there were no significant changes in: 1) mRNA levels in hypothalamus or pituitary for TRH, TSH, thyroid hormone receptor α and β, as well 10 other hormones or releasing factors; 2) mRNA levels in thyroid for thyroglobulin, thyroid peroxidase, sodium iodide symporter, or type I deiodinases; 3) serum TSH or T3 levels (T4 was decreased at high dose only); 4) dopaminergic tone in the hypothalamus and pituitary or importantly 5) increased cell proliferation (Mki67 mRNA and Ki-67 protein levels were not increased) in thyroid or pituitary. These negative findings are consistent with a genotoxic mechanism of AA carcinogenicity based on metabolism to glycidamide and DNA adduct formation. Clarification of this mechanistic dichotomy may be useful in human cancer risk

  19. Thyroid hormone stimulation of phosphatidylcholine synthesis in cultured fetal rabbit lung.

    OpenAIRE

    Ballard, P L; Hovey, M L; Gonzales, L K

    1984-01-01

    To investigate the mechanism of thyroid hormone action on pulmonary surfactant synthesis, we characterized the effect of triiodothyronine on phosphatidylcholine synthesis in cultured fetal rabbit lung. Since glucocorticoids stimulate surfactant synthesis and reduce the incidence of Respiratory Distress Syndrome in premature infants, we also examined the interaction of triiodothyronine and dexamethasone. The rate of choline incorporation into phosphatidylcholine was determined in organ culture...

  20. Extended hormone binding site of the human thyroid stimulating hormone receptor: distinctive acidic residues in the hinge region are involved in bovine thyroid stimulating hormone binding and receptor activation.

    Science.gov (United States)

    Mueller, Sandra; Kleinau, Gunnar; Jaeschke, Holger; Paschke, Ralf; Krause, Gerd

    2008-06-27

    The human thyroid stimulating hormone receptor (hTSHR) belongs to the glycoprotein hormone receptors that bind the hormones at their large extracellular domain. The extracellular hinge region of the TSHR connects the N-terminal leucine-rich repeat domain with the membrane-spanning serpentine domain. From previous studies we reasoned that apart from hormone binding at the leucine-rich repeat domain, additional multiple hormone contacts might exist at the hinge region of the TSHR by complementary charge-charge recognition. Here we investigated highly conserved charged residues in the hinge region of the TSHR by site-directed mutagenesis to identify amino acids interacting with bovine TSH (bTSH). Indeed, the residues Glu-297, Glu-303, and Asp-382 in the TSHR hinge region are essential for bTSH binding and partially for signal transduction. Side chain substitutions showed that the negative charge of Glu-297 and Asp-382 is necessary for recognition of bTSH by the hTSHR. Multiple combinations of alanine mutants of the identified positions revealed an increased negative effect on hormone binding. An assembled model suggests that the deciphered acidic residues form negatively charged patches at the hinge region resulting in an extended binding mode for bTSH on the hTSHR. Our data indicate that certain positively charged residues of bTSH might be involved in interaction with the identified negatively charged amino acids of the hTSHR hinge region. We demonstrate that the hinge region represents an extracellular intermediate connector for both hormone binding and signal transduction of the hTSHR.

  1. [Pharmacological approaches for correction of thyroid dysfunctions in diabetes mellitus].

    Science.gov (United States)

    Shpakov, A O

    2017-05-01

    Thyroid diseases are closely associated with the development of types 1 and 2 diabetes mellitus (DM), and as a consequence, the development of effective approaches for their treatment is one of the urgent problems of endocrinology. Traditionally, thyroid hormones (TH) are used to correct functions of the thyroid system. However, they are characterized by many side effects, such as their negative effect on the cardiovascular system as well as the ability of TH to enhance insulin resistance and to disturb insulin-producing function of pancreas, exacerbating thereby diabetic pathology. Therefore, the analogues of TH, selective for certain types of TH receptors, that do not have these side effects, are being developed. The peptide and low-molecular weight regulators of thyroid-stimulating hormone receptor, which regulate the activity of the thyroid axis at the stage of TH synthesis and secretion in thyrocytes, are being created. Systemic and intranasal administration of insulin, metformin therapy and drugs with antioxidant activity are effective for the treatment of thyroid pathology in types 1 and 2 DM. In the review, the literature data and the results of own investigations on pharmacological approaches for the treatment and prevention of thyroid diseases in patients with types 1 and 2 DM are summarized and analyzed.

  2. The urgency for optimization and harmonization of thyroid hormone analyses and their interpretation in developmental and reproductive toxicology studies.

    Science.gov (United States)

    Beekhuijzen, Manon; Schneider, Steffen; Barraclough, Narinder; Hallmark, Nina; Hoberman, Alan; Lordi, Sheri; Moxon, Mary; Perks, Deborah; Piersma, Aldert H; Makris, Susan L

    2018-05-02

    In recent years several OECD test guidelines have been updated and some will be updated shortly with the requirement to measure thyroid hormone levels in the blood of mammalian laboratory species. There is, however, an imperative need for clarification and guidance regarding the collection, assessment, and interpretation of thyroid hormone data for regulatory toxicology and risk assessment. Clarification and guidance is needed for 1) timing and methods of blood collection, 2) standardization and validation of the analytical methods, 3) triggers for additional measurements, 4) the need for T4 measurements in postnatal day (PND) 4 pups, and 5) the interpretation of changes in thyroid hormone levels regarding adversity. Discussions on these topics have already been initiated, and involve expert scientists from a number of international multisector organizations. This paper provides an overview of existing issues, current activities and recommendations for moving forward. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. [Hormones and hair growth].

    Science.gov (United States)

    Trüeb, R M

    2010-06-01

    With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair.

  4. Adrenal, thyroid, and testicular hormone rhythms in male golden hamsters on long and short days

    International Nuclear Information System (INIS)

    Ottenweller, J.E.; Tapp, W.N.; Pitman, D.L.; Natelson, B.H.

    1987-01-01

    Plasma concentrations of adrenal, thyroid, and testicular hormones were measured at 4-h intervals around the clock in male hamsters on long (14:10-h light-dark cycle) and short (10:14-h light-dark cycle) days. Plasma corticosterone, cortisol, thyroxine (T 4 ), triiodothyronine (T 3 ), and testosterone rhythms were present on long days. The only one of these hormones to have a significant rhythm on short days was cortisol, but even its amplitude was suppressed compared with the cortisol rhythm on long days. Short days also lowered mean plasma levels of cortisol, T 4 , T 3 , and testosterone. Finally, short days raised the ratio of corticosterone to cortisol and lowered the ratio of T 4 to T 3 . Both ratios had significant rhythms on long days but not on short days. Because of the many interactions among adrenal, thyroid, and testicular hormone axes, it is unclear whether the primary effect of short days is on one of these endocrine systems or on another factor that has separate effects on each of the hormone rhythms that was measured. Nonetheless, it is clear that a major effect of short day lengths in hamsters is to suppress hormone rhythms. Explanations of photoperiodic effects that depend on endocrine mediation should take this into account

  5. Thyroid Hormone Economy in the Perinatal Mouse Brain: Implications for Cerebral Cortex Development.

    Science.gov (United States)

    Bárez-López, Soledad; Obregon, Maria Jesus; Bernal, Juan; Guadaño-Ferraz, Ana

    2018-05-01

    Thyroid hormones (THs, T4 and the transcriptionally active hormone T3) play an essential role in neurodevelopment; however, the mechanisms underlying T3 brain delivery during mice fetal development are not well known. This work has explored the sources of brain T3 during mice fetal development using biochemical, anatomical, and molecular approaches. The findings revealed that during late gestation, a large amount of fetal brain T4 is of maternal origin. Also, in the developing mouse brain, fetal T3 content is regulated through the conversion of T4 into T3 by type-2 deiodinase (D2) activity, which is present from earlier prenatal stages. Additionally, D2 activity was found to be essential to mediate expression of T3-dependent genes in the cerebral cortex, and also necessary to generate the transient cerebral cortex hyperthyroidism present in mice lacking the TH transporter Monocarboxylate transporter 8. Notably, the gene encoding for D2 (Dio2) was mainly expressed at the blood-cerebrospinal fluid barrier (BCSFB). Overall, these data signify that T4 deiodinated by D2 may be the only source of T3 during neocortical development. We therefore propose that D2 activity at the BCSFB converts the T4 transported across the choroid plexus into T3, thus supplying the brain with active hormone to maintain TH homeostasis.

  6. Cardiac autonomic regulation is disturbed in children with euthyroid Hashimoto thyroiditis.

    Science.gov (United States)

    Kilic, Ayhan; Gulgun, Mustafa; Tascilar, Mehmet Emre; Sari, Erkan; Yokusoglu, Mehmet

    2012-03-01

    Hashimoto thyroiditis (chronic autoimmune thyroiditis) is the most common form of thyroiditis in childhood. Previous studies have found autonomic dysfunction of varying magnitude in patients with autoimmune diseases, which is considered a cardiovascular risk factor. We aimed to evaluate the heart rate variability (HRV), a measure of cardiac autonomic modulation, in children with euthyroid Hashimoto thyroiditis (eHT). The study included 32 patients with eHT (27 girls and 5 boys; mean age 11 ± 4.1 years, range 8-16; body mass index 0.47 ± 0.69 kg/m(2)), as judged by normal or minimally elevated serum TSH levels (normal range: 0.34-5.6 mIU/l) and normal levels of free thyroid hormones (FT4 and FT3) and 38 euthyroid age-matched controls. Patients with eHT and control subjects underwent physical examination and 24-hour ambulatory ECG monitoring. Time-domain parameters of HRV were evaluated for cardiac autonomic functions. Children with eHT displayed significantly lower values of time-domain parameters of SDANN (standard deviation of the averages of NN intervals), RMSSD (square root of the mean of the sum of the squares of differences between adjacent NN intervals), NN50 counts (number of pairs of adjacent NN intervals differing by more than 50 ms) and PNN50 (NN50 count divided by the total number of all NN intervals) for each 5-min interval, compared to healthy controls (p < 0.05 for each), indicating the decreased beat-to-beat variation of heart rate. In conclusion, eHT is associated with disturbed autonomic regulation of heart rate. Hence, the children with eHT are at higher risk for developing cardiovascular diseases.

  7. Effects of recombinant human growth hormone in the treatment of dwarfism and relationship between IGF-1, IGFBP-3 and thyroid hormone.

    Science.gov (United States)

    Ren, Shanxiang; Nie, Yuxiang; Wang, Aihong

    2016-12-01

    The effects of recombinant human growth hormone (rhGH) in the treatment of dwarfism and the relationship between insulin-like growth factor (IGF)-1, IGF-binding protein (IGFBP)-3 and thyroid hormone were examined in the present study. For this purpose, 66 patients diagnosed with dwarfism were selected retrospectively, with 36 cases of growth hormone deficiency (GHD) and 30 cases of idiopathic short stature (ISS). The therapeutic dose of GHD 0.10 IU/kg·day and ISS 0.15 IU/kg·day were injected subcutaneously every night before sleep until adulthood. The average follow-up was 5 years, and the results were evaluated and measured every 3 months, including height, BA, secondary test of growth hormone (GH peak), IGF-1, IGFBP-3 and thyroid hormone (FT3, FT4 and TSH). After treatment, the height, BA, GH peak, IGF-A and IGFBP-3 of the GHD group were all increased, and the differences were statistically significant (P0.05). The results of the Pearson-related analysis suggested that GH peak of the GHD group, IGF-1 and IGFBP-3 were positively associated with height (P0.05). rhGH was effective for GHD and ISS, with the GHD effect being positively associated with the GH peak, IGF-1 and IGFBP-3. ISS had no obvious relationship with GH peak, IGF-1 and IGFBP-3 although other influencing factors may be involved.

  8. Total Thyroidectomy for Thyroid Cancer Followed by Thyroid Storm due to Thyrotropin Receptor Antibody Stimulation of Metastatic Thyroid Tissue

    DEFF Research Database (Denmark)

    Folkestad, Lars; Brandt, Frans; Brix, Thomas

    2017-01-01

    BACKGROUND: Graves disease (GD) is an autoimmune condition characterized by the presence of antibodies against the thyrotropin receptor (TRAB), which stimulate the thyroid gland to produce excess thyroid hormone. Theoretically, TRAB could stimulate highly differentiated thyroid cancer tissue and...... treatment continued until after the fourth RAI dose. Hypothyroidism did not occur until following the fifth RAI treatment. SUMMARY AND CONCLUSIONS: We present a patient initially diagnosed with thyrotoxicosis and subsequently with metastatic follicular variant of papillary thyroid cancer. It is suggested...... that TRAB stimulated the highly differentiated extrathyroidal metastatic thyroid tissue to produce excessive amounts of thyroid hormone, delayed diagnosis, and potential aggravation of the course of thyroid cancer....

  9. Thyroid function, Alzheimer's disease and postoperative cognitive dysfunction: a tale of dangerous liaisons?

    Science.gov (United States)

    Mafrica, Federica; Fodale, Vincenzo

    2008-05-01

    Hypothyroidism and hyperthyroidism are commonly present conditions in adults, leading to neurological symptoms, affecting the central and peripheral nervous system, and to neurocognitive impairment. Several studies investigated a possible association between Alzheimer's disease (AD) and thyroid dysfunctions. Increasing evidence supports an extensive interrelationship between thyroid hormones and the cholinergic system, which is selectively and early affected in AD. Moreover, thyroid hormones negatively regulate expression of the amyloid-beta protein precursor (AbetaPP), which plays a key role in the development of AD. A condition, the so called euthyroid sick syndrome (ESS), characterized by reduced serum T_{3} and T_{4} concentrations without increased serum thyroid stimulation hormone secretion, occurs within hours after major surgery. After surgery, elderly patients often exhibit a transient, reversible state of cognitive alterations. Delirium occurs in 10-26% of general medical patients over 65, and it is associated with a significant increase in morbidity and mortality. Modifications in thyroid hormone functioning may take place as a consequence of psycho-physical stress caused by surgery, and probably as a consequence of reduced conversion of T4 into T3 by the liver engaged in metabolizing anesthetic drugs. Therefore, modifications of thyroid hormones post-surgery, might play a role in the pathogenesis of postoperative cognitive dysfunction.

  10. Glucoregulatory function of thyroid hormones: role of pancreatic hormones

    International Nuclear Information System (INIS)

    Mueller, M.J.B.; Burger, A.G.; Ferrannini, E.; Jequier, E.; Acheson, K.J.

    1989-01-01

    Glucose metabolism was investigated in humans before and 14 days after 300 micrograms L-thyroxine (T4)/day using a sequential clamp protocol during short-term somatostatin infusion (500 micrograms/h, 0-6 h) at euglycemia (0-2.5 h), at 165 mg/dl (2.5-6 h), and during insulin infusion (1.0 mU.kg-1.min-1, 4.5-6 h). T4 treatment increased plasma T4 (+96%) and 3,5,3'-triiodothyronine (T3, +50%), energy expenditure (+8%), glucose turnover (+32%), and glucose oxidation (Glucox +87%) but decreased thyroid-stimulating hormone (-96%) and nonoxidative glucose metabolism (Glucnonox, -30%) at unchanged lipid oxidation (Lipox). During somatostatin and euglycemia glucose production (Ra, -67%) and disposal (Rd, -28%) both decreased in euthyroid subjects but remained at -22% and -5%, respectively, after T4 treatment. Glucox (control, -20%; +T4, -25%) fell and Lipox increased (control, +42%; +T4, +45%) in both groups, whereas Glucnonox decreased before (-36%) but increased after T4 (+57%). During somatostatin infusion and hyperglycemia Rd (control, +144%; +T4, +84%) and Glucnonox (control, +326%; +T4, +233%) increased, whereas Glucox and Lipox remained unchanged. Insulin further increased Rd (+76%), Glucox (+155%), and Glucnonox (+50%) but decreased Ra (-43%) and Lipox (-43%). All these effects were enhanced by T4 (Rd, +38%; Glucox, +45%; Glucnonox, +35%; Ra, +40%; Lipox, +11%). Our data provide evidence that, in humans, T3 stimulates Ra and Rd, which is in part independent of pancreatic hormones

  11. Thyroiditis de Quervain. Are there predictive factors for long-term hormone-replacement?

    Science.gov (United States)

    Schenke, S; Klett, R; Braun, S; Zimny, M

    2013-01-01

    Subacute thyroiditis is a usually self-limiting disease of the thyroid. However, approximately 0.5-15% of the patients require permanent thyroxine substitution. Aim was to determine predictive factors for the necessity of long-term hormone-replacement (LTH). We retrospectively reviewed the records of 72 patients with subacute thyroiditis. Morphological and serological parameters as well as type of therapy were tested as predictive factors of consecutive hypothyroidism. Mean age was 49 ± 11 years, f/m-ratio was 4.5 : 1. Thyroid pain and signs of hyperthyroidism were leading symptoms. Initial subclinical or overt hyperthyroidism was found in 20% and 37%, respectively. Within six months after onset 15% and 1.3% of the patients developed subclinical or overt hypothyroidism, respectively. At latest follow-up 26% were classified as liable to LTH. At onset the thyroid was enlarged in 64%, and at latest follow-up in 8.3%, with a significant reduction of the thyroid volume after three months. At the endpoint the thyroid volume was less in patients in the LTH group compared with the non-LTH group (41.7% vs. 57.2% of sex-adjusted upper norm, p = 0.041). Characteristic ultrasonographic features occurred in 74% of the patients in both lobes. Serological and morphological parameters as well as type of therapy were not related with the need of LTH. In this study the proportion of patients who received LTH was 26%. At the endpoint these patients had a lower thyroid volume compared with euthyroid patients. No predictive factors for LTH were found.

  12. Thyroid stimulating hormone increases hepatic gluconeogenesis via CRTC2.

    Science.gov (United States)

    Li, Yujie; Wang, Laicheng; Zhou, Lingyan; Song, Yongfeng; Ma, Shizhan; Yu, Chunxiao; Zhao, Jiajun; Xu, Chao; Gao, Ling

    2017-05-05

    Epidemiological evidence indicates that thyroid stimulating hormone (TSH) is positively correlated with abnormal glucose levels. We previously reported that TSH has direct effects on gluconeogenesis. However, the underlying molecular mechanism remains unclear. In this study, we observed increased fasting blood glucose and glucose production in a mouse model of subclinical hypothyroidism (only elevated TSH levels). TSH acts via the classical cAMP/PKA pathway and CRTC2 regulates glucose homeostasis. Thus, we explore whether CRTC2 is involved in the process of TSH-induced gluconeogenesis. We show that TSH increases CRTC2 expression via the TSHR/cAMP/PKA pathway, which in turn upregulates hepatic gluconeogenic genes. Furthermore, TSH stimulates CRTC2 dephosphorylation and upregulates p-CREB (Ser133) in HepG2 cells. Silencing CRTC2 and CREB decreases the effect of TSH on PEPCK-luciferase, the rate-limiting enzyme of gluconeogenesis. Finally, the deletion of TSHR reduces the levels of the CRTC2:CREB complex in mouse livers. This study demonstrates that TSH activates CRTC2 via the TSHR/cAMP/PKA pathway, leading to the formation of a CRTC2:CREB complex and increases hepatic gluconeogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Treatment room length-of-stay and patient throughput with radioiodine thyroid remnant ablation in differentiated thyroid cancer: comparison of thyroid-stimulating hormone stimulation methods.

    Science.gov (United States)

    Vallejo Casas, Juan Antonio; Mena Bares, Luisa M; Gálvez, María Angeles; Marlowe, Robert J; Latre Romero, José M; Martínez-Paredes, María

    2011-09-01

    We sought to empirically compare treatment room length-of-stay and patient throughput for recombinant human thyroid-stimulating hormone (rhTSH)-aided thyroid remnant ablation with thyroid hormone withdrawal (THW)-aided ablation in patients with differentiated thyroid carcinoma (DTC). We retrospectively reviewed charts of all eligible (near) totally thyroidectomized patients with DTC undergoing ablation and 1-year ablation success evaluation at our tertiary referral centre from January 2003 to February 2009 (N=274). M1 disease caused exclusion unless discovered by a postablation scan or present when rhTSH was the only tolerable stimulation method. We extracted data on the length-of-stay, defined as the time between treatment room admission and discharge, and patient throughput, defined as patients ablated per treatment room per week. The treatment room discharge criterion was a whole-body dose rate of less than 60 μSv/h at 50 cm. The treatment groups (rhTSH, n=187; THW, n=87) had mostly statistically similar characteristics, but differed in primary tumour status distribution. In addition, at ablation, the rhTSH patients had a greater prevalence of prior diagnostic scintigraphy, higher mean serum TSH, and shorter interval since surgery, and received a 5.6% larger mean ablation activity. On average, rhTSH patients had a significantly lower peak whole-body dose rate (57.1 vs. 83.4 μSv/h at 50 cm; P<0.0001) and a significantly shorter treatment room stay than did the THW patients (1.41 vs. 2.02 days; P<0.001). rhTSH use allowed significantly more patients to be ablated per room per week (2.7 vs. 1.2; P<0.001). Relative to THW, rhTSH use to aid ablation reduced mean treatment room length-of-stay by almost one-third and more than doubled the average weekly patient throughput, both of which were significant differences.

  14. PREGNANCY AND THYROID

    Directory of Open Access Journals (Sweden)

    Simona Gaberšček

    2004-01-01

    Full Text Available Background. In conditions with appropriate iodine intake, thyroid gland adapts to changes during pregnancy without any consequences. Fetal need for thyroid hormones in the first trimester is directly connected with transplacental transport of thyroid hormones. Fetal synthesis of thyroid hormones depends on availability of iodine in the feto-placental unit. Hypo- and hyperthyroidism during pregnancy are risk factors for pregnant woman and for normal development of fetus and child.Conclusions. Pregnant women with appropriately treated thyroid diseases have the same outcome of pregnancy as healthy women, and neuroendocrinological development of children is not impaired. If the disease is unrecognized or untreated, complications of pregnancy and delivery occur more frequently. Therefore, timely recognition and treatment of the diseases with appropriate drugs during pregnancy and, also, after delivery is very important.

  15. Competitive binding thyroid assay with improved bound-free separation step

    International Nuclear Information System (INIS)

    1979-01-01

    A competitive binding assay is described for serum thyroid hormone using 125 I-labelled thyroid hormone and exogenous thyroid hormone binding protein. The unbound thyroid hormone is separated from thyroid hormone bound to thyroid hormone binding protein using an intermediate base anion exchange resin. This resin comprises tertiary and quaternary amine groups on a polyalkyleneamine lattice and is compressed with microcrystalline cellulose in a tablet form. The assay technique of the present invention employing an intermediate base anion resin was found to give superior results compared with alternative assay techniques used in serum thyroid hormone estimation. (UK)

  16. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

    Energy Technology Data Exchange (ETDEWEB)

    Bitencourt, C.S. [Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I. [Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-03-02

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

  17. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

    International Nuclear Information System (INIS)

    Bitencourt, C.S.; Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I.

    2012-01-01

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production

  18. Measurement of Thyroid-Stimulating Hormone (TSH) In Vitro

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, K. E.; Hunter, W. M.; Jeffery, F. H.; Bennie, J. G. [Medical Research Council Clinical Endocrinology Unit, Edinburgh, Scotland (United Kingdom)

    1970-02-15

    Many of the methods of assay proposed for the quantitative measurement of human thyroid-stimulating hormone (H-TSH) have encountered major difficulties in relation to sensitivity and specificity. The development of radioimmunoassay techniques for the measurement of H-TSH not only resulted in increased sensitivity over the majority of existing techniques, but led to improvements in specificity and practicability. The purpose of this communication is to compare serum TSH values measured by a method of bioassay in vitro with those obtained by a radioimmunoassay developed in this laboratory using reagents provided by the National Pituitary Agency, United States of America. In the bioassay technique goitrous guinea-pig thyroid tissue is incubated in vitro with {sup 131}I and H-TSH during which time the tissue takes up {sup 131}I and binds it in organic combination. Measurements of the radioactive content of the culture medium are made before and after the addition of KSCN in order to discharge any {sup 131}I present in the tissue as iodide, the difference in count-rate being indirectly proportional to the amount of H-TSH present in the incubation fluid. The method can detect as little as 1.0 mU/100 ml serum. The radioimmunoassay technique used was that described by Odell and Garigan in instructions accompanying the reagents. However, modifications to their technique included the use of antiserum at a final dilution of 1/120 000 and the addition of H-TSH at a final concentration of 0.4 ng/ml to mixtures of antiserum and the standard preparation after an incubation period of five days. After a further five days incubation period, the separation of bound and free {sup 131}I-H-TSH was carried out by precipitating the bound hormone with NaCl and ethanol. The lower limit of detection in terms of the H-TSH standard A (MRC) is 5 {mu}U/ml serum (0.5 mU/100 ml). Serum was obtained from children aged one month to 16 years, adults aged 18-40 years and 66-85 years, patients

  19. Milrinone and thyroid hormone stimulate myocardial membrane Ca2+-ATPase activity and share structural homologies.

    Science.gov (United States)

    Mylotte, K M; Cody, V; Davis, P J; Davis, F B; Blas, S D; Schoenl, M

    1985-01-01

    We have recently shown that thyroid hormone in physiological concentrations stimulates sarcolemma-enriched rabbit-myocardial-membrane Ca2+-ATPase in vitro. In this study, milrinone [2-methyl-5-cyano-(3,4'-bipyridin)-6(1H)-one], a cardiac inotropic agent, was thyromimetic in the same system. At clinically achievable concentrations (50-500 nM), milrinone significantly stimulated membrane Ca2+-ATPase in vitro. This action was antagonized by W-7 [N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide], an agent that also blocks thyroid hormone action on the Ca2+-ATPase, at concentrations as low as 5 microM. Progressive additions of milrinone to membranes incubated with a fixed concentration of thyroxine (0.10 nM) or triiodothyronine resulted in a progressive obliteration of the thyroid hormone effect on Ca2+-ATPase. Amrinone [5-amino-(3,4'-bipyridin)-6(1H)-one], the parent bipyridine of milrinone, had no effect on myocardial Ca2+-ATPase activity. X-ray crystallographic analysis of milrinone and amrinone revealed structural homologies between the phenolic ring of thyroxine and the substituted ring of milrinone, whereas amrinone did not share these homologies. The mechanism(s) of the inotropic actions of thyroxine and of milrinone is not clearly understood, but these observations implicate Ca2+-ATPase, a calcium pump-associated enzyme, as one mediator of the effects on the heart of these two compounds. PMID:2933747

  20. P38/TRHr-Dependent Regulation of TPO in Thyroid Cells Contributes to the Hypothyroidism of Triclosan-Treated Rats

    Directory of Open Access Journals (Sweden)

    Pei Zhang

    2018-02-01

    Full Text Available Background/Aims: Triclosan, as an antimicrobial agent and a potential endocrine disruptor, has been used extensively in diverse products, resulting in widespread human exposure. In recent years, studies suggest that triclosan could disturb thyroid functions and decline thyroid hormones (THs. Methods: To verify our hypothesis that the MAPK pathway may function significantly in triclosan-induced hypothyroidism, Sprague-Dawley rats were gavaged with triclosan for 31 consecutive days; Nthy-ori 3-1 cells were treated with triclosan in the presence/absence of NAC, inhibitors (SB203580 and SB202474, or TRHr siRNA. Tissues and/or cells were analyzed by several techniques including transmission electron microscopy, confocal laser scanning microscopy, gene silencing, western blot, and real-time PCR. Results: Triclosan led to histopathologic changes in the thyroid and decreases in triiodothyronine (T3 and thyroxine (T4. Triclosan stimulated ROS production and oxidative stress occurrence, thereby activating the p38 pathway in vivo and in vitro. Thyrotropin releasing hormone receptor (TRHr was induced when the p38 pathway was activated, and was suppressed when that pathway was inhibited. Moreover, thyroid peroxidase (TPO was restrained and modulated by the p38/TRHr pathway after triclosan treatment. Furthermore, deiodinase 3 (D3 and hepatic enzymes (Ugt2b1, CYP1a1, CYP1a2, CYP2b1, CYP3a1, and Sult1e1 were also induced by triclosan. Conclusion: Taken together, p38/TRHr-dependent regulation of TPO in thyroid cells contributes to the hypothyroidism of triclosan-treated rats.

  1. Radioiodine Thyroid Remnant Ablation after Recombinant Human Thyrotropin or Thyroid Hormone Withdrawal in Patients with High-Risk Differentiated Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Fabián Pitoia

    2012-01-01

    Full Text Available To supplement limited relevant literature, we retrospectively compared ablation and disease outcomes in high-risk differentiated thyroid carcinoma (DTC patients undergoing radioiodine thyroid remnant ablation aided by recombinant human thyrotropin (rhTSH versus thyroid hormone withdrawal/withholding (THW. Our cohort was 45 consecutive antithyroglobulin antibody- (TgAb- negative, T3-T4/N0-N1-Nx/M0 adults ablated with high activities at three referral centers. Ablation success comprised negative (<1 μg/L stimulated serum thyroglobulin (Tg and TgAb, with absent or <0.1% scintigraphic thyroid bed uptake. “No evidence of disease” (NED comprised negative unstimulated/stimulated Tg and no suspicious neck ultrasonography or pathological imaging or biopsy. “Persistent disease” was failure to achieve NED, “recurrence,” loss of NED status. rhTSH patients (n=18 were oftener ≥45 years old and higher stage (P=0.01, but otherwise not different than THW patients (n=27 at baseline. rhTSH patients were significantly oftener successfully ablated compared to THW patients (83% versus 67%, P<0.02. After respective 3.3 yr and 4.5 yr mean follow-ups (P=0.02, NED was achieved oftener (72% versus 59% and persistent disease was less frequent in rhTSH patients (22% versus 33% (both comparisons P=0.03. rhTSH stimulation is associated with at least as good outcomes as is THW in ablation of high-risk DTC patients.

  2. Radioiodine thyroid remnant ablation after recombinant human thyrotropin or thyroid hormone withdrawal in patients with high-risk differentiated thyroid cancer.

    Science.gov (United States)

    Pitoia, Fabián; Marlowe, Robert J; Abelleira, Erika; Faure, Eduardo N; Bueno, Fernanda; Schwarzstein, Diego; Lutfi, Rubén Julio; Niepomniszcze, Hugo

    2012-01-01

    To supplement limited relevant literature, we retrospectively compared ablation and disease outcomes in high-risk differentiated thyroid carcinoma (DTC) patients undergoing radioiodine thyroid remnant ablation aided by recombinant human thyrotropin (rhTSH) versus thyroid hormone withdrawal/withholding (THW). Our cohort was 45 consecutive antithyroglobulin antibody- (TgAb-) negative, T3-T4/N0-N1-Nx/M0 adults ablated with high activities at three referral centers. Ablation success comprised negative (<1 μg/L) stimulated serum thyroglobulin (Tg) and TgAb, with absent or <0.1% scintigraphic thyroid bed uptake. "No evidence of disease" (NED) comprised negative unstimulated/stimulated Tg and no suspicious neck ultrasonography or pathological imaging or biopsy. "Persistent disease" was failure to achieve NED, "recurrence," loss of NED status. rhTSH patients (n = 18) were oftener ≥45 years old and higher stage (P = 0.01), but otherwise not different than THW patients (n = 27) at baseline. rhTSH patients were significantly oftener successfully ablated compared to THW patients (83% versus 67%, P < 0.02). After respective 3.3 yr and 4.5 yr mean follow-ups (P = 0.02), NED was achieved oftener (72% versus 59%) and persistent disease was less frequent in rhTSH patients (22% versus 33%) (both comparisons P = 0.03). rhTSH stimulation is associated with at least as good outcomes as is THW in ablation of high-risk DTC patients.

  3. Comparison of Thyroid Hormones Consumption in Russia and European Countries

    OpenAIRE

    V V Fadeyev; T B Morgunova

    2009-01-01

    Hypothyroidism is one of the most common endocrine diseases. The prevalence of hypothyroidism in adults is estimated to be 1–2% for overt hypothyroidism and 7–10% for subclinical hypothyroidism, especially in elder women. Considering high prevalence of hypothyroidism and negative consequences of nontreated hypothyroidism for health, we conducted the work which aim was the assessment of consumption of thyroid hormones in Russia in comparison with the countries of Europe. The aim of this analys...

  4. Carriers of a VEGFA enhancer polymorphism selectively binding CHOP/DDIT3 are predisposed to increased circulating levels of thyroid-stimulating hormone

    DEFF Research Database (Denmark)

    Ahluwalia, Tarun Veer Singh; Troelsen, Jesper Thorvald; Balslev-Harder, Marie

    2017-01-01

    BACKGROUND: Levels of serum thyroid-stimulating hormone (TSH) indicate thyroid function, because thyroid hormone negatively controls TSH release. Genetic variants in the vascular endothelial growth factor A (VEGFA) gene are associated with TSH levels. The aim of this study was to characterise...... levels (p=0.0014). The SNP rs881858 is located in a binding site for CHOP (C/EBP homology protein) and c/EBPβ (ccaat enhancer binding protein β). Reporter-gene analysis showed increased basal enhancer activity of the rs881858 A-allele versus the G-allele (34.5±9.9% (average±SEM), p=0.0012), while co...

  5. Polychlorinated biphenyl-induced alterations of thyroid hormone homeostasis and brain development in the rat

    NARCIS (Netherlands)

    Morse, D.C.

    1995-01-01

    Introduction

    The work described in this thesis was undertaken to gain insight in the processes involved in the developmental neurotoxicity of polychlorinated biphenyls. It has been previously hypothesized that the alteration of thyroid hormone status by PCBs may

  6. Triiodothyronine affects the alternative splicing of thyroid hormone receptor alpha mRNA

    NARCIS (Netherlands)

    Timmer, D. C.; Bakker, O.; Wiersinga, W. M.

    2003-01-01

    The c-erbAalpha gene encodes two