Variable biological activity of thyroid-stimulating hormone

1994 ◽  
Vol 131 (4) ◽  
pp. 331-340 ◽  
Author(s):  
Paolo Beck-Peccoz ◽  
Luca Persani

Beck-Peccoz P, Persani L. Variable biological activity of thyroid-stimulating hormone. Eur J Endocrinol 1994;131:331–40. ISSN 0804–4643 Thyroid-stimulating hormone (TSH), like the other pituitary glycoprotein hormones, is produced and secreted as a mixture of isoforms, the majority of which represent differences in oligosaccharide structure and possess different bioactivity. When samples are quantified simultaneously by immunometric assay and bioassay, the ratio between bioactivity (B) and immunoreactivity (I) may serve as an index of the overall potency of TSH. Variations of the TSH B/I ratio have been documented in both physiological and pathological conditions associated with alteration of the two most important mechanisms controlling TSH synthesis and secretion, i.e. TRH release and the thyroid hormone feedback system. Major examples of this assumption are the low TSH bioactivity found in samples from patients lacking TRH and thus bearing a hypothalamic hypothyroidism, and the enhanced bioactivity that is invariably found in TSH from patients with thyroid hormone resistance. Moreover, variations of TSH bioactivity have been recorded in normal subjects during the nocturnal TSH surge, in normal fetuses during the last trimester of pregnancy, in patients with primary hypothyroidism and in patients with TSH-secreting pituitary adenoma and non-thyroidal illness. In conclusion, the secretion of TSH molecules with altered bioactivity plays an important pathogenetic role in various thyroid disorders, while in some particular physiological conditions the bioactivity of TSH may vary in order to adjust thyroid hormone secretion to temporary needs. Paolo Beck-Peccoz, Istituto di Scienze Endocrine, Ospedale Maggiore IRCCS, Via F. Sforza 35, 1-20122 Milano, Italy

2010 ◽  
Vol 56 (2) ◽  
pp. 179-186 ◽  
Author(s):  
N.V. Yaglova ◽  
T.T. Berezov

Activation of toll-like receptors-4 by bacterial lipopolysaccharide downregulates pituitary and thyroid function. Besides decrease of thyroid-stimulating hormone secretion lipopolysaccharide affects secretion in follicular thyroid cells directly. The endotoxin partialy activates and inhibits different phases of follicular thyrocytes' secretion. Lipopolysaccharide enhances thyroglobulin synthesis and exocytosis into follicular lumen and supresses its resorbtion.It results in sharp drop of blood thyroxine concentration without decrease of deiodinases-mediated thiroxine to triiodothyronine conversion. Stimulation of the lipopolysaccharide-pretreated thyroid gland with thyroid-stimulating hormone increases resorbtion of thyroglobulin and thyroid hormone production. Combined stimulation of the thyroid gland increases protein bound thyroxine and triiodothyronine serum concentration unlike only TSH stimulation resulting in increase of free thyroid hormone levels. It also prooves that binding capacity of thyroid hormone serum transport proteins during nonthyroidal illness syndrome remains normal.


2021 ◽  
Vol 53 (04) ◽  
pp. 272-279
Author(s):  
Chaochao Ma ◽  
Xiaoqi Li ◽  
Lixin Liu ◽  
Xinqi Cheng ◽  
Fang Xue ◽  
...  

AbstractThyroid hormone reference intervals are crucial for diagnosing and monitoring thyroid dysfunction during early pregnancy, and the dynamic change trend of thyroid hormones during pregnancy can assist clinicians to assess the thyroid function of pregnant women. This study aims to establish early pregnancy related thyroid hormones models and reference intervals for pregnant women. We established two derived databases: derived database* and derived database#. Reference individuals in database* were used to establish gestational age-specific reference intervals for thyroid hormones and early pregnancy related thyroid hormones models for pregnant women. Individuals in database# were apparently healthy non-pregnant women. The thyroid hormones levels of individuals in database# were compared with that of individuals in database* using nonparametric methods and the comparative confidence interval method. The differences in thyroid stimulating hormone and free thyroxine between early pregnant and non-pregnant women were statistically significant (p<0.0001). The reference intervals of thyroid stimulating hormone, free thyroxine and free triiodothyronine for early pregnant women were 0.052–3.393 μIU/ml, 1.01–1.54 ng/dl, and 2.51–3.66 pg/ml, respectively. Results concerning thyroid stimulating hormone and free thyroxine reference intervals of early pregnancy are comparable with those from other studies using the same detection platform. Early pregnancy related thyroid hormones models showed various change patterns with gestational age for thyroid hormones. Early pregnancy related thyroid hormones models and reference intervals for pregnant women were established, so as to provide accurate and reliable reference basis for the diagnosing and monitoring of maternal thyroid disfunction in early pregnancy.


1988 ◽  
Vol 22 (3) ◽  
pp. 202-204 ◽  
Author(s):  
Merlin V. Nelson ◽  
Vickie Tutag-Lehr ◽  
R. Lee Evans

Nine normal, healthy male subjects had significantly elevated thyroid-stimulating hormone (TSH) concentrations while receiving oral lithium carbonate for two weeks. The mean minimum lithium serum concentration was 0.765 mEq/L. The TSH concentrations after 15 days on lithium were significantly correlated to the TSH concentration at baseline. No correlation was found between mean minimum lithium steady-state concentration and TSH concentration after 15 days on lithium. Further research is necessary to determine if a high baseline TSH concentration or an early rise in TSH will predict those patients who will eventually develop hypothyroidism after long-term lithium therapy.


2006 ◽  
Vol 231 (3) ◽  
pp. 229-236 ◽  
Author(s):  
John R. Klein

It has been known for decades that the neuroendocrine system can both directly and indirectly influence the developmental and functional activity of the immune system. In contrast, far less is known about the extent to which the immune system collaborates in the regulation of endocrine activity. This is particularly true for immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis. Although thyroid-stimulating hormone (TSH) can be produced by many types of extra-pituitary cells-including T cells, B cells, splenic dendritic cells, bone marrow hematopoietic cells, intestinal epithelial cells, and lymphocytes—the functional significance of those TSH pathways remains elusive and historically has been largely ignored from a research perspective. There is now, however, evidence linking cells of the immune system to the regulation of thyroid hormone activity in normal physiological conditions as well as during times of immunological stress. Although the mechanisms behind this are poorly understood, they appear to reflect a process of local intrathyroidal synthesis of TSH mediated by a population of bone marrow cells that traffic to the thyroid. This hitherto undescribed cell population has the potential to micro-regulate thyroid hormone secretion leading to critical alterations in metabolic activity independent of pituitary TSH output, and it has expansive implications for understanding mechanisms by which the immune system may act to modulate neuroendocrine function during times of host stress. In this article, the basic underpinnings of the hematopoietic-thyrold connection are described, and a model is presented in which the immune system participates in the regulation of thyroid hormone activity during acute infection.


2016 ◽  
Vol 6 (4) ◽  
pp. 109-115
Author(s):  
Lara Moreira Baptista de Sousa ◽  
Elisa Baranski Lamback ◽  
Thomaz Schroder Lameirinhas ◽  
Michelle Botelho Caarls ◽  
Leonardo Vieira Neto

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