Androgens: Effects on Thyroid Binding Globulin?

Mr.50

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Guys I am wondering what effects the use of androgens has on thyroid binding globulin and any other proteins that may bind T4 and T3 keeping them inactive and not free? It is my understanding that all androgens lower Thyroid binding globulin but I am wondering if some do it more then others thus possibly describing a mechanism why some androgens are thought to be better for fat loss then others. There is more to all of this but I figure I will see if anyone even has any info on this line of thought before I go on.


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Chronic administration of anabolic androgenic steroid alters murine thyroid function.

Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D, Carvalho DP.

Endocrine Physiology Laboratory, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

PURPOSE: The administration of anabolic-androgenic steroids (AAS) to improve athletic performance has increased notably during the past three decades, even among nonathletes. Thyroid function is affected by AAS use in humans, although the mechanisms of the effects of AAS are unclear. We evaluated the effects on thyroid function of supraphysiologic doses of nandrolone decanoate (DECA), which is one of the most anabolic-androgenic steroids (AAS) used. METHODS: Male Wistar rats were treated with vehicle or 1 mg.100 g(-1) body weight (b.w.) of DECA, once a week for 8 wk, intramuscularly. We analyzed thyroperoxidase (TPO) activity, type 1 iodothyronine deiodinase (D1) activities in liver, kidney, pituitary, and thyroid, and serum levels of total T3, total T4, free T4, and TSH. Parametric and nonparametric t-tests were employed for statistical analyses. RESULTS: Treated animals showed a significant increase in the weight of kidneys and heart, and a decrease in the relative testis weight. Retroperitoneal adipose tissue was only slightly decreased. DECA treatment induced a significant increase in the absolute and relative thyroid gland weight. The concentrations of total serum T3, free T4, and TSH decreased significantly with treatment, but total serum T4 levels were unchanged. Thyroperoxidase activity was unaltered, whereas liver and kidney D1 activities were significantly increased, but pituitary and thyroid D1 did not change. CONCLUSION: Our data indicate that DECA exerts direct actions on the thyroid gland and in the peripheral metabolism of thyroid hormones and might lead to thyroid dysfunction.

PMID: 16531893 [PubMed - in process]
 

ripped218

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Chronic administration of anabolic androgenic steroid alters murine thyroid function.

Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D, Carvalho DP.

Endocrine Physiology Laboratory, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

PURPOSE: The administration of anabolic-androgenic steroids (anabolic steroids) to improve athletic performance has increased notably during the past three decades, even among nonathletes. Thyroid function is affected by AAS use in humans, although the mechanisms of the effects of AAS are unclear. We evaluated the effects on thyroid function of supraphysiologic doses of nandrolone decanoate (DECA), which is one of the most anabolic-androgenic steroids (AAS) used. METHODS: Male Wistar rats were treated with vehicle or 1 mg.100 g(-1) body weight (b.w.) of DECA, once a week for 8 wk, intramuscularly. We analyzed thyroperoxidase (TPO) activity, type 1 iodothyronine deiodinase (D1) activities in liver, kidney, pituitary, and thyroid, and serum levels of total T3, total T4, free T4, and TSH. Parametric and nonparametric t-tests were employed for statistical analyses. RESULTS: Treated animals showed a significant increase in the weight of kidneys and heart, and a decrease in the relative testis weight. Retroperitoneal adipose tissue was only slightly decreased. DECA treatment induced a significant increase in the absolute and relative thyroid gland weight. The concentrations of total serum T3, free T4, and TSH decreased significantly with treatment, but total serum T4 levels were unchanged. Thyroperoxidase activity was unaltered, whereas liver and kidney D1 activities were significantly increased, but pituitary and thyroid D1 did not change. CONCLUSION: Our data indicate that DECA exerts direct actions on the thyroid gland and in the peripheral metabolism of thyroid hormones and might lead to thyroid dysfunction.

PMID: 16531893 [PubMed - in process]
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Mr.50

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Interesting. My understanding had been that androgens decreased thyroid binding glob and that was why many thyroid parameters decreased. But from thi sarticle it appears that is not the case.

Mr.50
 

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