scholarly journals Maternal-Fetal Glucocorticoid Milieu Programs Hypothalamic-Pituitary-Thyroid Function of Adult Offspring

Endocrinology ◽  
2004 ◽  
Vol 145 (9) ◽  
pp. 4068-4072 ◽  
Author(s):  
Jennifer Slone-Wilcoxon ◽  
Eva E. Redei
Keyword(s):  
Thyroid Function ◽  
Female Offspring ◽  
Adult Offspring ◽  
Mrna Levels ◽  
Continuous Release ◽  
Fetal Plasma ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Low Levels

Abstract To assess the role of maternal glucocorticoid milieu on the hypothalamic-pituitary-thyroid function of the offspring, we adrenalectomized (ADX) pregnant dams on gestation d 8 and implanted a placebo pellet or a continuous release 50- or 75-mg corticosterone (CORT) pellet. Maternal ADX led to realignment of the balance between maternal and fetal plasma CORT levels, resulting in an increase in CORT of fetal origin in the maternal compartment. Maternal ADX and low levels of CORT replacement had no discernable effect on maternal pituitary-thyroid measures. In contrast, the increase in fetal CORT, as a consequence of the absence of maternal glucocorticoids, decreased birth weight in neonates, decreased adult hypothalamic TRH mRNA levels, and increased plasma TSH levels in both male and female adult offspring, all of which were reversed by administration of basal levels of CORT to the pregnant ADX dam. Decreased plasma T3 concentrations in female offspring were reversed by administration of the higher levels of CORT to the ADX dams. Our data indicate that maternal glucocorticoids modulate the developing hypothalamic-pituitary-thyroid axis.

scholarly journals Chronothyroidology: Chronobiological Aspects in Thyroid Function and Diseases

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 426
Author(s):  
Giuseppe Bellastella ◽  
Maria Ida Maiorino ◽  
Lorenzo Scappaticcio ◽  
Annamaria De Bellis ◽  
Silvia Mercadante ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Biological Rhythms ◽  
Cellular Level ◽  
Scientific Discipline ◽  
Biological Phenomena ◽  
Pituitary Thyroid Axis ◽  
Circadian Organization ◽  
Thyroid Axis ◽  
Central Clock ◽  
Thyroid Dysfunctions

Chronobiology is the scientific discipline which considers biological phenomena in relation to time, which assumes itself biological identity. Many physiological processes are cyclically regulated by intrinsic clocks and many pathological events show a circadian time-related occurrence. Even the pituitary–thyroid axis is under the control of a central clock, and the hormones of the pituitary–thyroid axis exhibit circadian, ultradian and circannual rhythmicity. This review, after describing briefly the essential principles of chronobiology, will be focused on the results of personal experiences and of other studies on this issue, paying particular attention to those regarding the thyroid implications, appearing in the literature as reviews, metanalyses, original and observational studies until 28 February 2021 and acquired from two databases (Scopus and PubMed). The first input to biological rhythms is given by a central clock located in the suprachiasmatic nucleus (SCN), which dictates the timing from its hypothalamic site to satellite clocks that contribute in a hierarchical way to regulate the physiological rhythmicity. Disruption of the rhythmic organization can favor the onset of important disorders, including thyroid diseases. Several studies on the interrelationship between thyroid function and circadian rhythmicity demonstrated that thyroid dysfunctions may affect negatively circadian organization, disrupting TSH rhythm. Conversely, alterations of clock machinery may cause important perturbations at the cellular level, which may favor thyroid dysfunctions and also cancer.

The Role of Tanycytes in the Hypothalamus-Pituitary-Thyroid Axis and the Possibilities for Their Genetic Manipulation

2019 ◽  
Vol 128 (06/07) ◽  
pp. 388-394
Author(s):  
Helge Müller-Fielitz ◽  
Markus Schwaninger
Keyword(s):  
Energy Homeostasis ◽  
Genetic Manipulation ◽  
Heart Function ◽  
Feedback Regulation ◽  
Target Organs ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Hpt Axis ◽  
The Brain

AbstractThyroid hormone (TH) regulation is important for development, energy homeostasis, heart function, and bone formation. To control the effects of TH in target organs, the hypothalamus-pituitary-thyroid (HPT) axis and the tissue-specific availability of TH are highly regulated by negative feedback. To exert a central feedback, TH must enter the brain via specific transport mechanisms and cross the blood-brain barrier. Here, tanycytes, which are located in the ventral walls of the 3rd ventricle in the mediobasal hypothalamus (MBH), function as gatekeepers. Tanycytes are able to transport, sense, and modify the release of hormones of the HPT axis and are involved in feedback regulation. In this review, we focus on the relevance of tanycytes in thyrotropin-releasing hormone (TRH) release and review available genetic tools to investigate the physiological functions of these cells.

scholarly journals Dominant Role of Thyrotropin-releasing Hormone in the Hypothalamic-Pituitary-Thyroid Axis

2005 ◽  
Vol 281 (8) ◽  
pp. 5000-5007 ◽  
Author(s):  
Amisra A. Nikrodhanond ◽  
Tania M. Ortiga-Carvalho ◽  
Nobuyuki Shibusawa ◽  
Koshi Hashimoto ◽  
Xiao Hui Liao ◽  
...  
Keyword(s):  
Dominant Role ◽  
Thyrotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

scholarly journals The Hypothalamic-Pituitary-Thyroid Axis in Cushing Syndrome before and after Curative Surgery

2020 ◽  
Author(s):  
Skand Shekhar ◽  
Raven McGlotten ◽  
Sunyoung Auh ◽  
Kristina I Rother ◽  
Lynnette K Nieman
Keyword(s):  
Thyroid Function ◽  
Cushing’S Syndrome ◽  
Cushing Syndrome ◽  
Cushing's Syndrome ◽  
Curative Surgery ◽  
Central Hypothyroidism ◽  
Duration Of Symptoms ◽  
Before And After ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

Abstract Background We do not fully understand how hypercortisolism causes central hypothyroidism or what factors influence recovery of the hypothalamic-pituitary-thyroid axis. We evaluated thyroid function during and after cure of Cushing’s syndrome (CS). Methods We performed a retrospective cohort study of adult patients with CS seen from 2005 – 2018 (cohort 1, c1, n=68) or 1985 – 1994 (cohort 2, c2, n=55) at a clinical research center. Urine (UFC) and diurnal serum cortisol (F: ~8AM and ~midnight (PM)), morning triiodothyronine (T3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) (c1) or hourly TSH from 1500-1900h (day) and 2400-04000h (night) (c2), were measured before and after curative surgery. Results While hypercortisolemic, 53% of c1 had central hypothyroidism (low/low normal fT4 + unelevated TSH). Of those followed long-term, 31% and 44% had initially subnormal FT4 and T3, respectively, which normalized 6—12 months after cure. Hypogonadism was more frequent in hypothyroid (69%) compared to euthyroid (13%) patients. Duration of symptoms, AM and PM F, ACTH, and UFC were inversely related to TSH, FT4 and/or T3 levels (r -0.24 to -0.52, P <0.0001 to 0.02). In c2, the nocturnal surge of TSH (mIU/L) was subnormal before (day 1.00±0.04 vs night 1.08±0.05, p=0.3) and normal at a mean of 8 months after cure (day 1.30±0.14 vs night 2.17±0.27, p=0.01). UFC >1000 μg /day was an independent adverse prognostic marker of time to thyroid hormone recovery. Conclusions Abnormal thyroid function, likely mediated by subnormal nocturnal TSH, is prevalent in Cushing’s syndrome and is reversible after cure.

scholarly journals The role of leptin in the regulation of TSH secretion in the fed state: in vivo and in vitro studies

2002 ◽  
Vol 174 (1) ◽  
pp. 121-125 ◽  
Author(s):  
TM Ortiga-Carvalho ◽  
KJ Oliveira ◽  
BA Soares ◽  
CC Pazos-Moura
Keyword(s):  
Fold Increase ◽  
Adult Rats ◽  
Fed State ◽  
Rat Pituitary ◽  
Pituitary Thyroid Axis ◽  
Tsh Secretion ◽  
Thyroid Axis

Leptin has been shown to stimulate the hypothalamus-pituitary-thyroid axis in fasting rodents; however, its role in thyroid axis regulation under physiological conditions is still under investigation. Here it was investigated in freely fed rats whether leptin modulates thyrotroph function in vivo and whether leptin has direct pituitary effects on TSH release. Since leptin is produced in the pituitary, the possibility was also investigated that leptin may be a local regulator of TSH release. TSH was measured by specific RIA. Freely fed adult rats 2 h after being injected with a single s.c. injection of 8 microg leptin/100 g body weight showed a 2-fold increase in serum TSH (P<0.05). Hemi-pituitary explants incubated with 10(-9) and 10(-7) M leptin for 2 h showed a reduced TSH release of 40 and 50% respectively (P<0.05). Conversely, incubation of hemi-pituitary explants with antiserum against leptin, aiming to block the action of locally produced leptin, resulted in higher TSH release (45%, P<0.05). In conclusion, also in the fed state, leptin has an acute stimulatory effect on TSH release in vivo, acting probably at the hypothalamus. However, the direct pituitary effect of leptin is inhibitory and data also provide evidence that in the rat pituitary leptin may act as an autocrine/paracrine inhibitor of TSH release.

scholarly journals Studies on the Physiological Role of Hypothalamic TRH on the Negative Feedback Mechanism of the Pituitary-Thyroid Axis

1979 ◽  
Vol 55 (6) ◽  
pp. 776-786
Author(s):  
Masatomo MORI ◽  
Kihachi OHSHIMA ◽  
Sakae MARUTA ◽  
Hitoshi FUKUDA ◽  
Yohnosuke SHIMOMURA ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Physiological Role ◽  
Feedback Mechanism ◽  
Negative Feedback Mechanism ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

scholarly journals Role of the Orexin System on the Hypothalamus-Pituitary-Thyroid Axis

2016 ◽  
Vol 10 ◽  
Author(s):  
Antonietta Messina ◽  
Carolina De Fusco ◽  
Vincenzo Monda ◽  
Maria Esposito ◽  
Fiorenzo Moscatelli ◽  
...  
Keyword(s):  
Pituitary Thyroid Axis ◽  
Thyroid Axis

Biological aspects of social phobia

1996 ◽  
Vol 8 (4) ◽  
pp. 87-89
Author(s):  
I.M. van Vliet
Keyword(s):  
Panic Disorder ◽  
Social Phobia ◽  
Metabolic Activity ◽  
General Anxiety ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Challenge Tests ◽  
Biological Aspects ◽  
Pituitary Adrenal Axis

SummaryIn contrast to the research in panic disorder, not much neurobiological studies have been conducted in social phobia. In challenge-tests using lactate or pentagastrin general anxiety and anxiety symptoms were induced in social phobies, although not as frequent is in panic disorder patients, but no specific social phobic anxiety was induced. The role of neurotransmitters such as serotonin, dopamine and noradrenalin is, as yet, unclear. There are no indications for abnormal hypothalamic-pituitary-adrenal-axis activity or abnormal hypothalamic-pituitary-thyroid-axis activity in social phobia. To the present, preliminary findings in neuroimaging studies show no differences between patients and controls, except a possibly diminished and reversible metabolic activity.

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