scholarly journals Inhibition of type I and type II iodothyronine deiodinase activity in rat liver, kidney and brain produced by selenium deficiency

1989 ◽  
Vol 259 (3) ◽  
pp. 887-892 ◽  
Author(s):  
G J Beckett ◽  
D A MacDougall ◽  
F Nicol ◽  
J R Arthur
Keyword(s):  
Body Weight ◽  
Thyroid Hormone ◽  
Feedback Inhibition ◽  
Selenium Deficiency ◽  
Stress Factors ◽  
Type I ◽  
Type Ii ◽  
Hormone Metabolism ◽  
Iodothyronine Deiodinase ◽  
Thyroid Hormone Metabolism

Selenium deficiency for periods of 5 or 6 weeks in rats produced an inhibition of tri-iodothyronine (T3) production from added thyroxine (T4) in brain, liver and kidney homogenate. This inhibition was reflected in plasma T4 and T3 concentrations, which were respectively increased and decreased in selenium-deficient animals. Although plasma T4 levels increased in selenium-deficient animals, this did not produce the normal feedback inhibition on thyrotropin release from the pituitary. Selenium deficiency was confirmed in the animals by decreased selenium-dependent glutathione peroxidase (Se-GSH-Px) activity in all of these tissues. Administration of selenium, as a single intraperitoneal injection of 200 micrograms of selenium (as Na2SeO3)/kg body weight completely reversed the effects of selenium deficiency on thyroid-hormone metabolism and partly restored the activity of Se-GSH-Px. Selenium administration at 10 micrograms/kg body weight had no significant effect on thyroid-hormone metabolism or on Se-GSH-Px activity in any of the tissues studied. The characteristic changes in plasma thyroid-hormone levels that occurred in selenium deficiency appeared not to be due to non-specific stress factors, since food restriction to 75% of normal intake or vitamin E deficiency produced no significant changes in plasma T4 or T3 concentration. These data are consistent with the view that the Type I and Type II iodothyronine deiodinase enzymes are seleno-enzymes or require selenium-containing cofactors for activity.

The role of selenium in thyroid hormone metabolism

1991 ◽  
Vol 69 (11) ◽  
pp. 1648-1652 ◽  
Author(s):  
John R. Arthur
Keyword(s):  
Thyroid Hormone ◽  
Iodine Deficiency ◽  
Selenium Deficiency ◽  
Major Influence ◽  
Type I ◽  
Hormone Metabolism ◽  
Thyroid Hormone Metabolism ◽  
Iodothyronine Deiodinases ◽  
Clinical Changes

In animals, decreases in selenium-containing glutathione peroxidase activity and the resultant impairment of peroxide metabolism can account for many, but not all of the biochemical and clinical changes caused by selenium deficiency. Recently, however, type I iodothyronine 5′-deiodinase has also been shown to be a selenium-containing enzyme. This explains the impairment of thyroid hormone metabolism caused by selenium deficiency in animals with a normal vitamin E status. Since iodothyronine 5′-deiodinases are essential for the production of the active thyroid hormone 3,5,3′-triiodothyronine, some of the consequences of selenium deficiency may result from thyroid changes rather than inability to metabolise peroxides. In particular, the impaired thyroid hormone metabolism may be responsible for decreased growth and resistance to cold stress in selenium-deficient animals. A further consequence of the role of selenium in thyroid hormone metabolism is the exacerbation of some of the thyroid changes in iodine deficiency by a concurrent selenium deficiency. Selenium status may therefore have a major influence on the outcome of iodine deficiency in both human and animal populations.Key words: selenium, thyroid hormones, iodothyronine deiodinases, iodine, nutritional disorders.

scholarly journals Effects of concomitant selenium and vitamin E administration on thyroid hormone metabolism in broilers

2018 ◽  
Vol 68 (3) ◽  
pp. 355
Author(s):  
A. C. PAPPAS ◽  
B. M. KOTSAMPASI ◽  
K. KALAMARAS ◽  
K. FEGEROS ◽  
G. ZERVAS ◽  
...  
Keyword(s):  
Vitamin E ◽  
Thyroid Hormone ◽  
Control Diet ◽  
Dietary Treatment ◽  
Tocopheryl Acetate ◽  
Type I ◽  
Hormone Metabolism ◽  
Iodothyronine Deiodinase ◽  
Thyroid Hormone Metabolism ◽  
Diet Control

A total of 400, as hatched, broilers were used to investigate the effect of selenium (Se) and vitamin E supplementation on thyroid hormones metabolism. There were 5 replicates of 4 dietary treatments namely: control (C), a soybean meal maize basal diet with adequate Se and vitamin E (0.3 mg Se per kg diet and 80 mg vitamin E per kg diet), control diet with Se added (Se+, with an additional 1 mg of Se per kg of diet), control diet with vitamin E added (E+, with an additional 350 mg of vitamin E per kg of diet) and Se+E+ (with additional 1 mg of Se and 350 mg of vitamin E per kg of diet). Diets were isonitrogenous and isocaloric. Zinc L-selenomethionine complex was used to increase Se content and dl-α-tocopheryl acetate to increase vitamin E content. The experiment lasted 42 days. Plasma Se concentration increased in Se+ groups, while whole blood glutathione peroxidase (GPx) activity increased in Se+, E+ and Se+E+ groups compared to control. Hepatic type I iodothyronine deiodinase (ID-I) and thyroid hormone concentrations were unaffected by any dietary treatment. It is concluded that supplementation with Se or vitamin Ε alone or in combination above animal’s requirements does not affect thyroid hormone metabolism and liver ID-I activity under the conditions examined.

scholarly journals Type 1 iodothyronine deiodinase in human physiology and disease

2011 ◽  
Vol 209 (3) ◽  
pp. 283-297 ◽  
Author(s):  
Ana Luiza Maia ◽  
Iuri Martin Goemann ◽  
Erika L Souza Meyer ◽  
Simone Magagnin Wajner
Keyword(s):  
Human Physiology ◽  
Thyroid Hormone ◽  
Active Form ◽  
Normal Function ◽  
Type I ◽  
Hormone Metabolism ◽  
Iodothyronine Deiodinase ◽  
Thyroid Hormone Metabolism ◽  
Iodothyronine Deiodinases

Thyroid hormone is essential for the normal function of virtually all tissues. The iodothyronine deiodinases catalyze the removal of an iodine residue from the pro-hormone thyroxine (T4) molecule, thus producing either the active form triiodothyronine (T3; activation) or inactive metabolites (reverse T3; inactivation). Type I deiodinase (D1) catalyzes both reactions. Over the last years, several studies have attempted to understand the mechanisms of D1 function, underlying its effects on normal thyroid hormone metabolism and pathological processes. Although peripheral D1-generated T3 production contributes to a portion of plasma T3 in euthyroid state, pathologically increased thyroidal D1 activity seems to be the main cause of the elevated T3 concentrations observed in hyperthyroid patients. On the other hand, D1-deficient mouse models show that, in the absence of D1, inactive and lesser iodothyronines are excreted in feces with the loss of associated iodine, demonstrating the scavenging function for D1 that might be particularly important in an iodine deficiency setting. Polymorphisms in the DIO1 gene have been associated with changes in serum thyroid hormone levels, whereas decreased D1 activity has been reported in the nonthyroid illness syndrome and in several human neoplasias. The current review aims at presenting an updated picture of the recent advances made in the biochemical and molecular properties of D1 as well as its role in human physiology.

scholarly journals The Type II Deiodinase Is Retrotranslocated to the Cytoplasm and Proteasomes via p97/Atx3 Complex

2013 ◽  
Vol 27 (12) ◽  
pp. 2105-2115 ◽  
Author(s):  
Rafael Arrojo e Drigo ◽  
Péter Egri ◽  
Sungro Jo ◽  
Balázs Gereben ◽  
Antonio C. Bianco
Keyword(s):  
Molecular Weight ◽  
Endoplasmic Reticulum ◽  
Thyroid Hormone ◽  
High Molecular Weight ◽  
20S Proteasome ◽  
Type I ◽  
Type Ii ◽  
Cell Models ◽  
Natural Substrate ◽  
Iodothyronine Deiodinase

The type II iodothyronine deiodinase (D2) is a type I endoplasmic reticulum (ER)-resident thioredoxin fold-containing selenoprotein that activates thyroid hormone. D2 is inactivated by ER-associated ubiquitination and can be reactivated by two ubiquitin-specific peptidase-class D2-interacting deubiquitinases (DUBs). Here, we used D2-expressing cell models to define that D2 ubiquitination (UbD2) occurs via K48-linked ubiquitin chains and that exposure to its natural substrate, T4, accelerates UbD2 formation and retrotranslocation to the cytoplasm via interaction with the p97-ATPase complex. D2 retrotranslocation also includes deubiquitination by the p97-associated DUB Ataxin-3 (Atx3). Inhibiting Atx3 with eeyarestatin-I did not affect D2:p97 binding but decreased UbD2 retrotranslocation and caused ER accumulation of high-molecular weight UbD2 bands possibly by interfering with the D2-ubiquitin-specific peptidases binding. Once in the cytosol, D2 is delivered to the proteasomes as evidenced by coprecipitation with 19S proteasome subunit S5a and increased colocalization with the 20S proteasome. We conclude that interaction between UbD2 and p97/Atx3 mediates retranslocation of UbD2 to the cytoplasm for terminal degradation in the proteasomes, a pathway that is accelerated by exposure to T4.

scholarly journals Characterization of Human Iodothyronine Sulfotransferases1

1999 ◽  
Vol 84 (4) ◽  
pp. 1357-1364 ◽  
Author(s):  
Monique H. A. Kester ◽  
Ellen Kaptein ◽  
Thirza J. Roest ◽  
Caren H. van Dijk ◽  
Dick Tibboel ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Human Liver ◽  
Type I ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Iodothyronine Deiodinase ◽  
Liver Cytosol ◽  
Thyroid Hormone Metabolism ◽  
Liver And Kidney ◽  
Phenol Sulfotransferase

Sulfation is an important pathway of thyroid hormone metabolism that facilitates the degradation of the hormone by the type I iodothyronine deiodinase, but little is known about which human sulfotransferase isoenzymes are involved. We have investigated the sulfation of the prohormone T4, the active hormone T3, and the metabolites rT3 and 3,3′-diiodothyronine (3,3′-T2) by human liver and kidney cytosol as well as by recombinant human SULT1A1 and SULT1A3, previously known as phenol-preferring and monoamine-preferring phenol sulfotransferase, respectively. In all cases, the substrate preference was 3,3′-T2 >> rT3 > T3 > T4. The apparent Km values of 3,3′-T2 and T3 [at 50 μmol/L 3′-phosphoadenosine-5′-phosphosulfate (PAPS)] were 1.02 and 54.9μ mol/L for liver cytosol, 0.64 and 27.8 μmol/L for kidney cytosol, 0.14 and 29.1 μmol/L for SULT1A1, and 33 and 112 μmol/L for SULT1A3, respectively. The apparent Km of PAPS (at 0.1μ mol/L 3,3′-T2) was 6.0 μmol/L for liver cytosol, 9.0μ mol/L for kidney cytosol, 0.65 μmol/L for SULT1A1, and 2.7μ mol/L for SULT1A3. The sulfation of 3,3′-T2 was inhibited by the other iodothyronines in a concentration-dependent manner. The inhibition profiles of the 3,3′-T2 sulfotransferase activities of liver and kidney cytosol obtained by addition of 10 μmol/L of the various analogs were better correlated with the inhibition profile of SULT1A1 than with that of SULT1A3. These results indicate similar substrate specificities for iodothyronine sulfation by native human liver and kidney sulfotransferases and recombinant SULT1A1 and SULT1A3. Of the latter, SULT1A1 clearly shows the highest affinity for both iodothyronines and PAPS, but it remains to be established whether it is the prominent isoenzyme for sulfation of thyroid hormone in human liver and kidney.

scholarly journals Effect of selenium deficiency on hepatic type I 5-iodothyronine deiodinase activity and hepatic thyroid hormone levels in the rat

1992 ◽  
Vol 282 (2) ◽  
pp. 483-486 ◽  
Author(s):  
G J Beckett ◽  
A Russell ◽  
F Nicol ◽  
P Sahu ◽  
C R Wolf ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Selenium Deficiency ◽  
Type I ◽  
Hepatic Enzymes ◽  
Glutathione S Transferase ◽  
Iodothyronine Deiodinase ◽  
Hepatic Glutathione ◽  
Liver Homogenates ◽  
Thyroid Hormone Levels ◽  
Gst Activity

Selenium deficiency in rats for a period of up to 6 weeks inhibited both the production of 3,3′, 5-tri-iodothyronine (T3) from thyroxine (T4) (5′-deiodination) and also the catabolism of T3 to 3,3′-di-iodothyronine (5-deiodination) in liver homogenates. The hepatic stores of T3 were decreased by only 8% in selenium deficiency, despite the T3 production rate from T4 being only 7% of the rate found in selenium-supplemented rats. Hepatic glutathione S-transferase (GST) activity was increased in both hypothyroidism and selenium deficiency, but apparently by different mechanisms, since mRNA expression for this family of enzymes was lowered by hypothyroidism and increased in selenium deficiency. It is concluded that, since both T3 production and catabolism are inhibited by selenium deficiency, there is little change in hepatic T3 stores, and therefore the changes in the activity of certain hepatic enzymes, such as GST, that are found in selenium deficiency are not the result of tissue hypothyroidism.

Effect of administration of growth hormone on plasma and intracellular levels of thyroxine and tri-iodothyronine in thyroidectomized thyroxine-treated rats

1992 ◽  
Vol 133 (1) ◽  
pp. 45-49 ◽  
Author(s):  
P. H. L. M. Geelhoed-Duijvestijn ◽  
F. Roelfsema ◽  
J. P. Schröder-van der Elst ◽  
J. van Doorn ◽  
D. van der Heide
Keyword(s):  
Body Weight ◽  
Type I ◽  
Hormone Metabolism ◽  
Lower Plasma ◽  
Thyroid Hormone Metabolism ◽  
Deiodinase Activity ◽  
Appearance Rate ◽  
Male Wistar Rats ◽  
Wet Weight ◽  
Peripheral Production

ABSTRACT We have studied the effects of the administration of GH on plasma levels and peripheral production of tri-iodothyronine (T3) from thyroxine (T4) in thyroidectomized male Wistar rats given a continuous i.v. infusion of T4 (1 μg/100 g body weight per day) and GH (120 μg per day) for 3 weeks. Tracer doses of 131I-labelled T3 and 125I-labelled T4 were added to the infusion. At isotopic equilibrium (10 days after the addition of 125I-labelled T4) the rats were bled and perfused. The plasma appearance rate for T3 was higher (10·6±1·3 vs 8·4 ± 2·8 pmol/h per 100 g body weight, P = 0·05) and plasma TSH was lower (246±24 vs 470±135 pmol/l, P<0·01) in GH-treated rats. The amount of T3 in liver (12·3 ±2·8 vs 5·5 ± 1·7 pmol/g wet weight, P<0·01), kidney (11·5±1·4 vs 6·5± 1·4 pmol/g wet weight, P <0·01) and pituitary (8·8 ±2·7 vs 4·8±0·5 pmol/g wet weight, P< 0·01) was higher than in controls, mainly as a result of an increased local production of T3 from T4, but plasma-derived T3 was also higher in most organs. We found an increased intracellular T3 concentration in the pituitary which may be responsible for the lower plasma TSH concentration in the GH-treated rats. Since the increase in locally produced T3 is found particularly in liver, kidney and pituitary, typical organs that express 5′-deiodinase activity, we suggest that GH acts on thyroid hormone metabolism by stimulating type-I deiodinase activity. Journal of Endocrinology (1992) 133, 45–49

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