Mild hyperthyroidism with inappropriate secretion of TSH in postmenopausal women

1986 ◽  
Vol 111 (2) ◽  
pp. 204-208 ◽  
Author(s):  
N. Custro ◽  
V. Scafidi
Keyword(s):  
Thyroid Hormones ◽  
Postmenopausal Women ◽  
Present Report ◽  
Serum Levels ◽  
Suppressive Effect ◽  
Pituitary Thyroid Axis ◽  
Tsh Secretion ◽  
Thyroid Axis ◽  
Suppression Test ◽  
Inappropriate Tsh Secretion

Abstract. In a previous study on the function of the hypothalamus - pituitary - thyroid axis, about 10% of postmenopausal women with the climacteric syndrome were found to have borderline high values of T3 and T4 and signs of pituitary decreased sensitivity to the suppressive effect of increased thyroid hormones. The present report concerns 5 women in the first phase of their menopause who showed a mild hyperthyroidism under basal conditions and after suppression test with liothyronine. Each patient had borderline increased levels of serum total and free T4 and T3 and a marked TSH responsiveness to exogenous TRH. After liothyronine, the serum levels of T4, FT4, TSH and the responsiveness to TRH-test clearly decreased. These data suggest an inappropriate TSH secretion with a decreased pituitary sentitivity to thyroid hormones. These cases could represent a modification of the hypothalamus-pituitary-thyroid axis associated with that of the gonadal axis, secondary to the absence of rapid adaptation of neurotransmitters.

scholarly journals Type 3 Deiodinase Role on Central Thyroid Hormone Action Affects the Leptin-Melanocortin System and Circadian Activity

Endocrinology ◽  
2016 ◽  
Vol 158 (2) ◽  
pp. 419-430 ◽  
Author(s):  
Zhaofei Wu ◽  
M. Elena Martinez ◽  
Donald L. St. Germain ◽  
Arturo Hernandez
Keyword(s):  
Energy Balance ◽  
Elevated Serum ◽  
Serum Levels ◽  
Leptin Resistance ◽  
Melanocortin System ◽  
White Adipocyte ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
The Central Nervous System ◽  
Type 3

Abstract The role of thyroid hormones (THs) in the central regulation of energy balance is increasingly appreciated. Mice lacking the type 3 deiodinase (DIO3), which inactivates TH, have decreased circulating TH levels relative to control mice as a result of defects in the hypothalamic-pituitary-thyroid axis. However, we have shown that the TH status of the adult Dio3−/− brain is opposite that of the serum, exhibiting enhanced levels of TH action. Because the brain, particularly the hypothalamus, harbors important circuitries that regulate metabolism, we aimed to examine the energy balance phenotype of Dio3−/− mice and determine whether it is associated with hypothalamic abnormalities. Here we show that Dio3−/− mice of both sexes exhibit decreased adiposity, reduced brown and white adipocyte size, and enhanced fat loss in response to triiodothyronine (T3) treatment. They also exhibit increased TH action in the hypothalamus, with abnormal expression and T3 sensitivity of genes integral to the leptin-melanocortin system, including Agrp, Npy, Pomc, and Mc4r. The normal to elevated serum levels of leptin, and elevated and repressed expression of Agrp and Pomc, respectively, suggest a profile of leptin resistance. Interestingly, Dio3−/− mice also display elevated locomotor activity and increased energy expenditure. This occurs in association with expanded nighttime activity periods, suggesting a disrupted circadian rhythm. We conclude that DIO3-mediated regulation of TH action in the central nervous system influences multiple critical determinants of energy balance. Those influences may partially compensate each other, with the result likely contributing to the decreased adiposity observed in Dio3−/− mice.

Influence of meal composition on the postprandial response of the pituitary–thyroid axis

1995 ◽  
Vol 133 (1) ◽  
pp. 75-79 ◽  
Author(s):  
Vinay Kamat ◽  
Wendy L Hecht ◽  
Robert T Rubin
Keyword(s):  
Significant Decline ◽  
Randomized Design ◽  
Postprandial Response ◽  
Pituitary Thyroid Axis ◽  
Tsh Secretion ◽  
Thyroid Axis ◽  
Normal Men ◽  
Allegheny General Hospital ◽  
Serum Tsh ◽  
Meal Composition

Kamat V, Hecht WL, Rubin RT. Influence of meal composition on the postprandial response of the pituitary–thyroid axis. Eur J Endocrinol 1995;133:75–9. ISSN 0804–4643 Ingestion of food can result in an acute decline of serum thyrotropin (TSH) concentrations, but it is not known whether meal composition and/or stomach distension are influential. Normal men and women were given a normocaloric or hypocaloric, isobulk meal at lunch and at dinner in a randomized design. The normocaloric, but not the isobulk, meal resulted in a significant decline in serum TSH at both lunch and dinner; thyroid hormones and cortisol were not affected significantly. These findings suggest that meal composition is influential in the acute postprandial decline of serum TSH in man. A possible mechanism is food-induced elevation of somatostatin and consequent suppression of TSH secretion. Robert T Rubin, Neurosciences Research Center, Allegheny General Hospital, 320 E North Ave. Pittsburgh, PA 15212-4772, USA

scholarly journals The pituitary-thyroid axis in healthy men living under subarctic climatological conditions

2001 ◽  
Vol 169 (1) ◽  
pp. 195-203 ◽  
Author(s):  
J Hassi ◽  
K Sikkila ◽  
A Ruokonen ◽  
J Leppaluoto
Keyword(s):  
Thyroid Hormones ◽  
Climatic Factors ◽  
Feedback Mechanism ◽  
Free Triiodothyronine ◽  
Serum Free ◽  
Healthy Men ◽  
Non Invasive ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Serum Tsh

In order to evaluate the effects of climatic factors on the secretion of thyroid hormones and TSH in a high latitude population, we have taken serum and urine samples from 20 healthy men from northern Finland (67 degrees -68 degrees N) every 2 months for a period of 14 months. Serum free triiodothyronine (T(3)) levels were lower in February than in August (3.9 vs 4.4 pmol/l, P<0.05) and TSH levels were higher in December than during other months (2.1 vs 1.5-1.7 mU/l, P<0.01). Serum total and free thyroxine (T(4)), total T(3) and reverse T(3) levels and urinary T(4) levels were unchanged. Urinary T(3) levels were significantly higher in winter than in summer. Serum free T(3) correlated highly significantly with the outdoor temperature integrated backwards weekly for 7-56 days (r=0.26 for 1-56 days) from the day when the blood samples were taken. Serum TSH did not show any significant correlation with the thyroid hormones or with the integrated temperature of the previous days, but it did show an inverse and significant correlation (r=-0.31) with the ambient luminosity integrated backwards for 7 days from the day when the blood sample was taken. The gradually increasing correlation between outdoor temperatures and serum free T(3) suggests that the disposal of thyroid hormones is accelerated in winter, leading to low serum free T(3) levels and a high urinary free T(3) excretion. Since there was no correlation between thyroid hormones and serum TSH, the feedback mechanism between TSH and thyroid hormones may not be the only contributing factor, and other factors such as ambient luminosity may at least partly determine serum TSH in these conditions. Also urinary free T(3) appears to be a novel and non-invasive indicator for thyroid physiology.

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.

Effect of Iopanoic Acid on the Pituitary-Thyroid Axis: Time Sequence of Changes in Serum Iodothyronines, Thyrotropin, and Prolactin Concentrations and Responses to Thyroid Hormones*

1981 ◽  
Vol 53 (4) ◽  
pp. 779-783 ◽  
Author(s):  
HOJI SUZUKI ◽  
KAZUYA NOGUCHI ◽  
MOTONOBU NAKAHATA ◽  
SHOICHI NAKAGAWA ◽  
NARIYUKI KADENA
Keyword(s):  
Thyroid Hormones ◽  
Time Sequence ◽  
Iopanoic Acid ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

Kinetics of the Pituitary-Thyroid Axis and the Peripheral Thyroid Hormones in 2 Children with Thyroxine Intoxication

1995 ◽  
Vol 44 (5) ◽  
pp. 229-237 ◽  
Author(s):  
Igor Kaiserman ◽  
Maytal Avni ◽  
Joseph Sack
Keyword(s):  
Thyroid Hormones ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Kinetics Of

THE EFFECT OF STREPTOZOTOCIN-INDUCED DIABETES ON THE PITUITARY-THYROID AXIS IN GOITROGEN-TREATED RATS

1977 ◽  
Vol 86 (1) ◽  
pp. 128-139 ◽  
Author(s):  
Isabel Pericás ◽  
Trinidad Jolín
Keyword(s):  
Body Weight ◽  
Thyroid Function ◽  
Growth Response ◽  
Thyroid Tissue ◽  
Diabetic Rats ◽  
Poor Growth ◽  
Pituitary Thyroid Axis ◽  
Tsh Secretion ◽  
Thyroid Axis ◽  
Intact Rats

ABSTRACT Studies of pituitary and thyroid function have been carried out in normal (intact) and diabetic Wistar rats. Diabetes was induced by a single streptozotocin injection (7 mg/100 g body weight). The animals were fed a low iodine diet (LID), and received a daily sc injection of either KClO4 (20 mg/100 g body weight) or propylthiouracil (PTU) (1.5 mg/100 g body weight) to induce hypothyroidism. Control groups received the same LID but supplemented with 0.8 μg I/g dry weight. In intact rats goitrogen-treatment induces an increase in thyroid weight and in plasma TSH concentration. However, the plasma TSH response to goitrogen-treatment in diabetics indicates that pituitary TSH secretion increases following a reduction in plasma PBI, but the response is less marked than in controls. The difference in plasma TSH between control and diabetic rats provides an explanation for the findings that diabetes diminishes the thyroid growth response to goitrogen-treatment. Moreover, in intact rats the low pituitary TSH content is a consequence of the increase in pituitary TSH secretion, while in the diabetics the low pituitary TSH content cannot be explained by an increase in TSH secretion. The effect of diabetes on the pituitary-thyroid axis cannot be attributed specifically to poor growth, because the changes in pituitary-thyroid function which are observed in the diabetic groups are not seen in intact rats with a growth rate similar to that of insulin deficient rats. Insulin administration to goitrogen-treated diabetic rats results in 1) an increase in the ability of the thyroid tissue to respond to its trophic hormone, 2) an increase in pituitary TSH secretion in response to the lowering of plasma PBI and, 3) an increase in thyroid growth response to goitrogen-treatment. Results are discussed in relation to the assumption that the lack of adequate insulin levels, or its metabolic defects, diminishes the full response of the thyroid to TSH, and affects the pituitary TSH secretion probably as a consequence of altered hypothalamic control of the pituitary function.

scholarly journals Effects of Age, Body Weight and Sex on Pituitary-Thyroid Axis in Dairy Cattle and Daily Variations of Thyrotropin and Thyroid Hormones

1981 ◽  
Vol 52 (5) ◽  
pp. 343-348
Author(s):  
Koichi HODATE ◽  
Tetsu JOHKE ◽  
Asao KAWABATA ◽  
Kyoko HODATE
Keyword(s):  
Body Weight ◽  
Dairy Cattle ◽  
Thyroid Hormones ◽  
Daily Variations ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis
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