Endogenous Excitatory Amino Acid Neurotransmission Regulates Thyroid-Stimulating Hormone and Thyroid Hormone Secretion in Conscious Freely Moving Male Rats

Endocrine ◽  
2002 ◽  
Vol 17 (3) ◽  
pp. 193-198 ◽  
Author(s):  
M C Arufe ◽  
R Durán ◽  
D Perez-Vences ◽  
M Alfonso
Keyword(s):  
Amino Acid ◽  
Thyroid Hormone ◽  
Excitatory Amino Acid ◽  
Hormone Secretion ◽  
Thyroid Stimulating Hormone ◽  
Male Rats ◽  
Freely Moving ◽  
Stimulating Hormone

Variable biological activity of thyroid-stimulating hormone

1994 ◽  
Vol 131 (4) ◽  
pp. 331-340 ◽  
Author(s):  
Paolo Beck-Peccoz ◽  
Luca Persani
Keyword(s):  
Biological Activity ◽  
Thyroid Hormone ◽  
Hormone Secretion ◽  
Feedback System ◽  
Normal Subjects ◽  
Thyroid Stimulating Hormone ◽  
Primary Hypothyroidism ◽  
Oligosaccharide Structure ◽  
Pathological Conditions ◽  
Stimulating Hormone

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

scholarly journals Regulation of thyroid and pituitary function by bacterial lipopolysaccharide

2010 ◽  
Vol 56 (2) ◽  
pp. 179-186 ◽  
Author(s):  
N.V. Yaglova ◽  
T.T. Berezov
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Binding Capacity ◽  
Hormone Secretion ◽  
Thyroid Stimulating Hormone ◽  
Bacterial Lipopolysaccharide ◽  
Hormone Production ◽  
Thyroid Cells ◽  
Stimulation Of ◽  
Stimulating Hormone

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.

Establishment of Early Pregnancy Related Thyroid Hormone Models and Reference Intervals for Pregnant Women in China Based on Real World Data

2021 ◽  
Vol 53 (04) ◽  
pp. 272-279
Author(s):  
Chaochao Ma ◽  
Xiaoqi Li ◽  
Lixin Liu ◽  
Xinqi Cheng ◽  
Fang Xue ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Pregnant Women ◽  
Early Pregnancy ◽  
Gestational Age ◽  
Dynamic Change ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Stimulating Hormone

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.

A role for inhibin in the control of follicle-stimulating hormone secretion in male rats

Life Sciences ◽  
1985 ◽  
Vol 36 (9) ◽  
pp. 889-899 ◽  
Author(s):  
Henry M. Jones ◽  
Constance L. Wood ◽  
Michael E. Rush
Keyword(s):  
Follicle Stimulating Hormone ◽  
Hormone Secretion ◽  
Male Rats ◽  
Stimulating Hormone

scholarly journals The Immune System as a Regulator of Thyroid Hormone Activity

2006 ◽  
Vol 231 (3) ◽  
pp. 229-236 ◽  
Author(s):  
John R. Klein
Keyword(s):  
Bone Marrow ◽  
Immune System ◽  
Thyroid Hormone ◽  
Bone Marrow Cells ◽  
Acute Infection ◽  
Hormone Secretion ◽  
Thyroid Stimulating Hormone ◽  
Pituitary Cells ◽  
Hormone Activity ◽  
Endocrine Activity

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.

Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone antagonist-treated male rats

1995 ◽  
Vol 132 (3) ◽  
pp. 357-362 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
E Aguilar
Keyword(s):  
Gnrh Antagonist ◽  
Follicle Stimulating Hormone ◽  
Hormone Secretion ◽  
Gonadotropin Releasing Hormone ◽  
Male Rats ◽  
Gonadotropin Secretion ◽  
Releasing Hormone ◽  
Treated Male ◽  
Lh Secretion ◽  
Stimulating Hormone

Tena-Sempere M, Pinilla L, Aguilar E. Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone agonist-treated male rats. Eur J Endocrinol 1995;132: 357–62. ISSN 0804–4643 The pituitary component of the feedback mechanisms exerted by testicular factors on gonadotropin secretion was analyzed in adult male rats treated with a potent gonadotropin-releasing hormone (GnRH) antagonist. In order to discriminate between androgens and testicular peptides, groups of males were orchidectomized (to eliminate androgens and non-androgenic testicular factors) or injected with ethylene dimethane sulfonate (EDS), a selective toxin for Leydig cells (to eliminate selectively androgens) and treated for 15 days with vehicle or the GnRH antagonist Ac-d-pClPhe-d-pClPhe-d-TrpSer-Tyr-d-Arg-Leu-Arg-Pro-d-Ala-NH2CH3COOH (Org.30276, 5 mg/kg/72 hours). Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured 7 and 14 days after the beginning of treatment. We found that: in males treated with GnRH antagonist, orchidectomy or EDS treatment did not induce any increase in LH secretion; and orchidectomy, but not EDS treatment, increased FSH secretion in GnRH-treated males. The present results show that negative feedback of testicular factors on LH secretion is mediated completely through changes in GnRH actions. In contrast, a part of the inhibitory action of the testis on FSH secretion is exerted directly at the pituitary level. It can be hypothesized that non-Leydig cell testicular factor(s) inputs at different levels of the hypothalamic–pituitary axis in controlling LH and FSH secretion. Manuel Tena-Sempere, Department of Physiology, Faculty of Medicine, University of Córdoba, 14004 Córdoba, Spain

In vivo effects of flavonoid EMD 21388 on thyroid hormone secretion and metabolism in rats

1991 ◽  
Vol 261 (2) ◽  
pp. E227-E232 ◽  
Author(s):  
J. P. Schroder-van der Elst ◽  
D. van der Heide ◽  
J. Kohrle
Keyword(s):  
Thyroid Hormone ◽  
Hormone Secretion ◽  
Male Rats ◽  
Intact Male ◽  
Hormone Production ◽  
Iodide Uptake ◽  
Brown Adipose ◽  
In Vivo Effects

In vitro, the synthetic flavonoid EMD 21388 appears to be a potent inhibitor of thyroxine (T4) 5'-deiodinase and diminishes binding of T4 to transthyretin. In this study, in vivo effects of long-term administration of EMD 21388 on thyroid hormone production and metabolism were investigated. Intact male rats received EMD 21388 (20 mumol.kg body wt-1.rat-1.day-1) for 14 days. [125I]T4 and 3,5,3'-[131I]triiodotyronine (T3) were infused continuously and intravenously in a double-isotope protocol for the last 10 and 7 days, respectively. EMD 21388 decreased plasma thyroid hormone concentrations, but thyrotropin levels in plasma and pituitary did not change. Plasma clearance rates for T4 and T3 increased. Thyroidal T4 secretion was diminished, but T3 secretion was elevated. Extrathyroidal T3 production by 5'-deiodination was lower. T4 concentrations were markedly lower in all tissues investigated. Total tissue T3 was lower in brown adipose tissue, brain, cerebellum, and pituitary, tissues that express the type II 5'-deiodinase isozyme due to decreased local T3 production. Most tissues showed increased tissue/plasma ratios for T4 and T3. These results indicate that this flavonoid diminished T4 and increased T3 secretion by the thyroid, probably in analogy with other natural flavonoids, by interference with one or several steps between iodide uptake, organification, and hormone synthesis.

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