The Role of Glucocorticoids in the Stress-Induced Reduction of Extrathyroidal 3,5,3′-Triiodothyronine Generation in Rats*

Bianco, Antonio C.; Nunes, Maria Tereza; Hell, Naomi Shinomiya; Maciel, Rui M. B.

doi:10.1210/endo-120-3-1033

Cited by 97 publications

(61 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…During food restriction, in addition to decreased leptin, serum corticosterone is significantly increased (9,28). Some authors found that leptin administration is able to reverse the increased serum corticosterone (1, 17); however, in the present study serum corticosterone remained elevated in the leptintreated rats.…”

Section: Discussioncontrasting

confidence: 73%

Tissue-specific deiodinase regulation during food restriction and low replacement dose of leptin in rats

Araújo

Andrade²,

Silva³

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

Araujo RL, Andrade BM, da Silva ML, Ferreira AC, Carvalho DP. Tissue-specific deiodinase regulation during food restriction and low replacement dose of leptin in rats. Am J Physiol Endocrinol Metab 296: E1157-E1163, 2009. First published February 10, 2009 doi:10.1152/ajpendo.90869.2008The relationship between thyroid function and leptin has been extensively studied; however, the mechanisms underlying the changes in thyroid hormone economy that occur during caloric deprivation remain elusive. Our goal was to evaluate the thyroid function of rats submitted to 40% food restriction after chronic leptin replacement. Caloric restriction for 25 days led to significantly reduced serum leptin, thyroid-stimulating hormone (TSH), thyroxine (T 4), and triiodothyronine (T3) and increased serum corticosterone, while liver, kidney, and thyroid type I deiodinase (D1) and brown adipose tissue (BAT) type II deiodinase (D2) activities were decreased and hypothalamic D2 was significantly increased. Interestingly, thyroid iodide uptake was unchanged by caloric restriction, but thyroperoxidase (TPO) activity was significantly reduced. Leptin replacement for the last 10 days of caloric restriction normalized serum leptin and TSH levels, but serum T 4 and T3 levels and thyroid D1 and TPO activities were not reestablished. Also, a negative effect of leptin administration on Na ϩ -I Ϫ symporter function was detected. Liver and kidney D1 and hypothalamic and BAT D2 were normalized by leptin, while pituitary D2 was significantly decreased. In conclusion, a tissue-specific modulation of deiodinases might be implicated in the normalization of thyroid function during leptin replacement in food-restricted rats. Although leptin restores the hypothalamus-pituitary axis during food restriction, it exerts a direct negative effect on the thyroid gland; thus normalization of serum thyroid hormones might depend on changes in deiodinase activities and the long-term thyroid stimulation by TSH to counterbalance the direct negative effects of leptin on the thyroid gland.hypothalamus; pituitary; thyroid; caloric deprivation; thyrotropin MODERATE REDUCTION in caloric intake promotes well-known systemic effects such as body and fat mass reduction; however, homeostatic mechanisms impair further weight loss after longer periods of food restriction (40, 41). Studies in rodents suggest that the reduction in serum leptin levels that occurs during weight loss signals to the central nervous system, leading to decreased energy expenditure (1,2,3,5). This rapid fall in serum leptin in response to starvation also suppresses immunity, reproductive, and thyroid functions through central mechanisms (1,16,21,23,46).It is well documented that food restriction exerts profound effects on the hypothalamic-pituitary-thyroid axis, resulting in low plasma thyroxine (T 4 ) and triiodothyronine (T 3 ) levels that seem to be secondary to decreased thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) secretion (4,29,38). The relationship between thyroid hormon...

show abstract

Section: Discussioncontrasting

confidence: 73%

Tissue-specific deiodinase regulation during food restriction and low replacement dose of leptin in rats

Araújo

Andrade²,

Silva³

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

show abstract

“…Because we did not observe differences in T4, the decrease in T3 may be due to a disruption in type 2 deiodinase activity (D2). Glucocorticoids inhibit the conversion of T4 to T3 [79] although glucocorticoids can increase D2 activity in other models [80]. Plans are underway to examine specifically how social status affects each component of the HP-thyroid axis and how this is modified by SERT genotype.…”

Section: Discussionmentioning

confidence: 99%

Polymorphisms in the serotonin reuptake transporter gene modify the consequences of social status on metabolic health in female rhesus monkeys

Jarrell¹,

Hoffman²,

Kaplan³

et al. 2008

Physiology & Behavior

109

163

View full text Add to dashboard Cite

Individuals vary substantially in their vulnerability to physical and psychosocial stressors. The causes of such variation in susceptibility to stress are poorly understood, but are thought to relate in part to genetic factors. The present study evaluated the extent to which polymorphisms in the gene encoding the serotonin reuptake transporter (5HTTLPR or SERT) modulated physiologic responses to the imposition of psychosocial stress (social reorganization and subordinate social status) in female rhesus monkeys. Forty females, drawn from the middle ranking genealogies of several large social groups, were reorganized into eight groups containing 5 monkeys each; four groups were comprised entirely of animals homogeneous for the long promoter variant in the SERT gene (l/l), while the other four groups had monkeys with at least one allele of the short promoter variant (l/s or s/s). Females were sequentially introduced into these new groups in random order and dominance ranks were established within several days. During the ensuing 6 weeks, dominant monkeys exhibited elevated rates of aggression while subordinates displayed high rates of submission. Notably, females with the s-variant SERT genotype, collapsed across social status positions, exhibited the highest overall rates of both aggression and submission. Although neither social status nor SERT genotype influenced morning cortisol concentrations, glucocorticoid negative feedback was reduced significantly in subordinate compared to dominant females irrespective of genotype. All animals lost weight and abdominal fat across the experiment. However, decreases were greatest in subordinates, regardless of genotype, and least in dominant females with the l/l genotype. Serum concentrations of insulin, glucose, and ghrelin decreased significantly during the group formation process, effects that were independent of genotype or social status. In contrast, social status and genotype interacted to influence changes in serum concentrations of leptin and triiodothyronine (T3), as dominant, l/l females had the highest levels while subordinate s-variant females had the lowest levels. The order in which a female was introduced to her group generally predicted her eventual social rank. However, rank was additionally predicted by pre-experimental T3 and abdominal fat values, but only in the l/l animals. While these findings must be replicated with a larger sample size, the data suggest that the s-variant SERT genotype confers increased vulnerability to the adverse effects of psychosocial stress associated with subordinate status while the l/l genotype benefits the most from the absence of stress conferred by dominant social status. These findings suggest that genetic factors modify the responses of monkeys to social subordination and perhaps other psychosocial stressors.

show abstract

“…A large number of animal models have been developed to study NTI (361)(362)(363)(364)(365)(366)(367)(368)(369)(370). Essentially, the type and extent of the bodily insult that triggers NTI in rats, mice, and rabbits determines the magnitude of the alterations in thyroid economy.…”

Section: And Recommendation 34mentioning

confidence: 99%

American Thyroid Association Guide to Investigating Thyroid Hormone Economy and Action in Rodent and Cell Models

Bianco

Anderson

Forrest

et al. 2014

Thyroid

Self Cite

176

106

View full text Add to dashboard Cite

The Role of Glucocorticoids in the Stress-Induced Reduction of Extrathyroidal 3,5,3′-Triiodothyronine Generation in Rats*

Cited by 97 publications

References 30 publications

Tissue-specific deiodinase regulation during food restriction and low replacement dose of leptin in rats

Tissue-specific deiodinase regulation during food restriction and low replacement dose of leptin in rats

Polymorphisms in the serotonin reuptake transporter gene modify the consequences of social status on metabolic health in female rhesus monkeys

American Thyroid Association Guide to Investigating Thyroid Hormone Economy and Action in Rodent and Cell Models

Contact Info

Product

Resources

About