scholarly journals Deiodinase Activities in Thyroids and Tissues of Iodine-Deficient Female Rats

Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 529-536 ◽  
Author(s):  
Rosalia Lavado-Autric ◽  
Rosa Maria Calvo ◽  
Raquel Martinez de Mena ◽  
Gabriella Morreale de Escobar ◽  
Maria-Jesus Obregon
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Cerebral Cortex ◽  
Brown Adipose Tissue ◽  
Female Rats ◽  
Iodothyronine Deiodinase ◽  
Brown Adipose ◽  
Type 3

Severe iodine deficiency is characterized by goiter, preferential synthesis, and secretion of T3 in thyroids, hypothyroxinemia in plasma and tissues, normal or low plasma T3, and slightly increased plasma TSH. We studied changes in deiodinase activities and mRNA in several tissues of rats maintained on low-iodine diets (LIDs) or LIDs supplemented with iodine (LID+I). T4 and T3 concentrations decreased in plasma, tissues, and thyroids of LID rats, and T4 decreased more than T3 (50%). The highest type 1 iodothyronine deiodinase (D1) activities were found in the thyroid, kidney, and the liver; pituitary, lung, and ovary had lower D1 activities; but the lowest levels were found in the heart and skeletal muscle. D1 activity decreased in all tissues of LID rats (10–40% of LID+I rats), except for ovary and thyroids, which D1 activity increased 2.5-fold. Maximal type 2 iodothyronine deiodinase (D2) activities were found in thyroid, brown adipose tissue, and pituitary, increasing 6.5-fold in thyroids of LID rats and about 20-fold in the whole gland. D2 always increased in response to LID, and maximal increases were found in the cerebral cortex (19-fold), thyroid, brown adipose tissue, and pituitary (6-fold). Lower D2 activities were found in the ovary, heart, and adrenal gland, which increased in LID. Type 3 iodothyronine deiodinase activity was undetectable. Thyroidal Dio1 and Dio2 mRNA increased in the LID rats, and Dio1 decreased in the lung, with no changes in mRNA expression in other tissues. Our data indicate that LID induces changes in deiodinase activities, especially in the thyroid, to counteract the low T4 synthesis and secretion, contributing to maintain the local T3 concentrations in the tissues with D2 activity.

Dopaminergic Input from the Posterior Hypothalamus to the Raphe Pallidus Area Inhibits Brown Adipose Tissue Thermogenesis

2021 ◽  
Author(s):  
Ellen Paula Santos da Conceição Furber ◽  
Clarissa M.D. Mota ◽  
Edward Veytsman ◽  
Shaun F. Morrison ◽  
Christopher J. Madden
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Posterior Hypothalamus ◽  
Brown Adipose ◽  
Premotor Neurons ◽  
Brown Adipose Tissue Thermogenesis ◽  
Pre Treatment ◽  
Type 3 ◽  
Raphe Pallidus

Systemic administration of dopamine (DA) receptor agonists leads to falls in body temperature. However, the central thermoregulatory pathways modulated by DA have not been fully elucidated. Here we identified a source and site of action contributing to DA's hypothermic action by inhibition of brown adipose tissue (BAT) thermogenesis. Nanoinjection of the type 2 and type 3 DA receptor (D2R/D3R) agonist, 7-OH-DPAT, in the rostral raphe pallidus area (rRPa) inhibits the sympathetic activation of BAT evoked by cold exposure or by direct activation of NMDA receptors in the rRPa. Blockade of D2R/D3R in the rRPa with nanoinjection of SB-277011A increases BAT thermogenesis, consistent with a tonic release of DA in the rRPa contributing to inhibition of BAT thermogenesis. Accordingly, D2R are expressed in cold-activated and serotonergic neurons in the rRPa and anatomical tracing studies revealed that neurons in the posterior hypothalamus (PH) are a source of dopaminergic input to the rRPa. Disinhibitory activation of PH neurons with nanoinjection of gabazine inhibits BAT thermogenesis, which is reduced by pre-treatment of the rRPa with SB-277011A. In conclusion, the rRPa, the site of sympathetic premotor neurons for BAT, receives a tonically-active, dopaminergic input from the PH that suppresses BAT thermogenesis.

Inhibition of Type 1 Iodothyronine Deiodinase by Bisphenol A

2019 ◽  
Vol 51 (10) ◽  
pp. 671-677 ◽  
Author(s):  
Maurício Martins da Silva ◽  
Carlos Frederico Lima Gonçalves ◽  
Leandro Miranda-Alves ◽  
Rodrigo Soares Fortunato ◽  
Denise P. Carvalho ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Thyroid Hormone ◽  
Bisphenol A ◽  
Brown Adipose Tissue ◽  
Tissue Type ◽  
Deiodinase Activity ◽  
Brown Adipose

AbstractPlastics are ubiquitously present in our daily life and some components of plastics are endocrine-disrupting chemicals, such as bisphenol A and phthalates. Herein, we aimed to evaluate the effect of plastic endocrine disruptors on type 1 and type 2 deiodinase activities, enzymes responsible for the conversion of the pro-hormone T4 into the biologically active thyroid hormone T3, both in vitro and in vivo. Initially, we incubated rat liver type 1 deiodinase and brown adipose tissue type 2 deiodinase samples with 0.5 mM of the plasticizers, and the deiodinase activity was measured. Among them, only BPA was capable to inhibit both type 1 and type 2 deiodinases. Then, adult male Wistar rats were treated orally with bisphenol A (40 mg/kg b.w.) for 15 days and hepatic type 1 deiodinase and brown adipose tissue type 2 deiodinase activities and serum thyroid hormone concentrations were measured. In vivo bisphenol A treatment significantly reduced hepatic type 1 deiodinase activity but did not affect brown adipose tissue type 2 deiodinase activity. Serum T4 levels were higher in bisphenol A group, while T3 remained unchanged. T3/T4 ratio was decreased in rats treated with bisphenol A, reinforcing the idea that peripheral metabolism of thyroid hormone was affected by bisphenol A exposure. Therefore, our results suggest that bisphenol A can affect the metabolism of thyroid hormone thus disrupting thyroid signaling.

scholarly journals Metabolically Active Brown Adipose Tissue Is Found in Adult Subjects with Type 1 Diabetes

2019 ◽  
Vol 20 (23) ◽  
pp. 5827 ◽  
Author(s):  
Eriksson ◽  
Selvaraju ◽  
Berglund ◽  
Espes
Keyword(s):  
Skeletal Muscle ◽  
Type 1 Diabetes ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Metabolic Control ◽  
Metabolic Activity ◽  
Glucose Utilization ◽  
Insulin Requirements ◽  
Brown Adipose

Type 1 diabetes (T1D) is characterized by the loss of insulin-producing cells and hence insulin secretion and metabolic control. In addition to insulin, there are a number of hormones and cytokines that influence metabolism, and many of these can be secreted from brown adipose tissue (BAT). However, the presence and activity of BAT in T1D have not been studied, despite the fact that preclinical studies have shown that transplantation of BAT in mouse models of T1D can restore metabolic control. The metabolic activity of BAT, white adipose tissue (WAT), and skeletal muscle was investigated in patients with T1D (n = 11) by 2-deoxy-2-(18F)fluoro-D-glucose PET/CT after cold stimulation. Functional BAT was detected in 4 out of 11 individuals with T1D with a prevalence of 36%. The glucose utilization rate in the supraclavicular BAT regions ranged from 0.75–38.7 µmol × min−1 × 100 g−1. The glucose utilization per gram tissue was higher in BAT when compared with both WAT (p = 0.049) and skeletal muscle (p = 0.039). However, no correlation between BAT activity and metabolic control or insulin requirements was found. In conclusion, for the first time, cold-induced BAT was detected in patients with T1D with a wide range in metabolic activity. Contrary to findings in animal models, the metabolic activity of BAT had negligible impact on insulin requirements or metabolic control in T1D under normal physiological conditions.

scholarly journals The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue

2001 ◽  
Vol 108 (9) ◽  
pp. 1379-1385 ◽  
Author(s):  
Lucia A. de Jesus ◽  
Suzy D. Carvalho ◽  
Mirian O. Ribeiro ◽  
Mark Schneider ◽  
Sung-Woo Kim ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Iodothyronine Deiodinase ◽  
Adaptive Thermogenesis ◽  
Brown Adipose

Type 2 iodothyronine deiodinase is upregulated in rat slow- and fast-twitch skeletal muscle during cold exposure

2014 ◽  
Vol 307 (11) ◽  
pp. E1020-E1029 ◽  
Author(s):  
Ruy A. Louzada ◽  
Maria C. S. Santos ◽  
João Paulo A. Cavalcanti-de-Albuquerque ◽  
Igor F. Rangel ◽  
Andrea C. F. Ferreira ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Soleus Muscle ◽  
Cold Exposure ◽  
Skeletal Muscles ◽  
Nonshivering Thermogenesis ◽  
Brown Adipose

During cold acclimation, shivering is progressively replaced by nonshivering thermogenesis. Brown adipose tissue (BAT) and skeletal muscle are relevant for nonshivering thermogenesis, which depends largely on thyroid hormone. Since the skeletal muscle fibers progressively adapt to cold exposure through poorly defined mechanisms, our intent was to determine whether skeletal muscle type 2 deiodinase (D2) induction could be implicated in the long-term skeletal muscle cold acclimation. We demonstrate that in the red oxidative soleus muscle, D2 activity increased 2.3-fold after 3 days at 4°C together with the brown adipose tissue D2 activity, which increased 10-fold. Soleus muscle and BAT D2 activities returned to the control levels after 10 days of cold exposure, when an increase of 2.8-fold in D2 activity was detected in white glycolytic gastrocnemius but not in red oxidative gastrocnemius fibers. Propranolol did not prevent muscle D2 induction, but it impaired the decrease of D2 in BAT and soleus after 10 days at 4°C. Cold exposure is accompanied by increased oxygen consumption, UCP3, and PGC-1α genes expression in skeletal muscles, which were partialy prevented by propranolol in soleus and gastrocnemius. Serum total and free T3 is increased during cold exposure in rats, even after 10 days, when BAT D2 is already normalized, suggesting that skeletal muscle D2 activity contributes significantly to circulating T3 under this adaptive condition. In conclusion, cold exposure is accompanied by concerted changes in the metabolism of BAT and oxidative and glycolytic skeletal muscles that are paralleled by type 2 deiodinase activation.

Blunted Response of Pituitary Type 1 and Brown Adipose Tissue Type 2 Deiodinases to Swimming Training in Ovariectomized Rats

2012 ◽  
Vol 44 (11) ◽  
pp. 797-803 ◽  
Author(s):  
D. Ignacio ◽  
R. Fortunato ◽  
R.A. Neto ◽  
D. da Silva Silvestre ◽  
M. Nigro ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Ovariectomized Rats ◽  
Tissue Type ◽  
Swimming Training ◽  
Brown Adipose

Adaptive Activation of Thyroid Hormone and Energy Expenditure

2005 ◽  
Vol 25 (3-4) ◽  
pp. 191-208 ◽  
Author(s):  
Antonio C. Bianco ◽  
Ana Luiza Maia ◽  
Wagner Seixas da Silva ◽  
Marcelo A. Christoffolete
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Thyroid Hormone ◽  
Energy Expenditure ◽  
Cold Exposure ◽  
Biological Knowledge ◽  
Iodothyronine Deiodinase ◽  
Brown Adipose ◽  
Adult Humans

The mechanisms by which thyroid hormone accelerates energy expenditure are poorly understood. In the brown adipose tissue (BAT), activation of thyroid hormone by type 2 iodothyronine deiodinase (D2) has been known to play a role in adaptive energy expenditure during cold exposure in human newborns and other small mammals. Although BAT is not present in significant amounts in normal adult humans, recent studies have found substantial amounts of D2 in skeletal muscle, a metabolically relevant tissue in humans. This article reviews current biological knowledge about D2 and adaptive T3 production and their roles in energy expenditure.

Early weaning alters the thermogenic capacity of brown adipose tissue in adult male and female rats

2019 ◽  
Vol 59 (5) ◽  
pp. 2207-2218 ◽  
Author(s):  
T. C. Peixoto ◽  
C. B. Pietrobon ◽  
I. M. Bertasso ◽  
F. A. H. Caramez ◽  
C. Calvino ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Adult Male ◽  
Female Rats ◽  
Early Weaning ◽  
Male And Female ◽  
Male And Female Rats ◽  
Brown Adipose ◽  
Thermogenic Capacity
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