On the Role of the Pituitary Stalk in the Regulation of the Anterior Pituitary, With Special Reference to the Thyrotropic Hormone1

Uotila, U.

doi:10.1210/endo-25-4-605

Cited by 71 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, these results confirm earlier observations indicating that the acute thyrotropic and corticotropic responses to cold are mediated via a neural pathway rather than a feedback mechanism (Uotila, 1939;Von Euler and Holmgren, 1956;Fortier et at., 1957). Evidence for this includes (1) the rapidity of the initial elevation of plasma TSH and of plasma corticosterone, pointing to an even more rapid rise of ACTH; (2) the absence of any significant fall of the variables under feedback control, e.g.…”

Section: Discussionsupporting

confidence: 90%

Interactions between the Pituitary, Thyroid and Adrenal Cortex during Acute Exposure to Cold or to Electric Shocks in the Rat

Jobin¹,

Delgado²,

Fortier³

1975

Horm Res

View full text Add to dashboard Cite

In intact rats acclimated to 25 ± 1°C, acute exposure to cold resulted in simultaneous stimulation of TSH and ACTH secretion. The plasma TSH response to cold was identical at temperatures varying from + 14 to -10°C, whereas the adrenocortical response increased proportionally to the severity of cold. Acute stimulation of ACTH secretion by exposure to a stressful situation (electrical shocks) did not alter the TSH response to cold. Conversely, acute blockade of the pituitary-adrenocortical response by dexamethasone treatment did not enhance the TSH response to cold. Chronic stimulation of ACTH secretion resulting from adrenalectomy did not interfere with the TSH response during subsequent exposure to cold. However, a reduced adrenocortical response to cold was observed during chronic hypersecretion of TSH resulting from previous thyroidectomy. These findings do not support the hypothesis of an inverse relationship between TSH and ACTH secretions during acute cold exposure, but rather suggest that these secretions are independent.

show abstract

Section: Discussionsupporting

confidence: 90%

Interactions between the Pituitary, Thyroid and Adrenal Cortex during Acute Exposure to Cold or to Electric Shocks in the Rat

Jobin¹,

Delgado²,

Fortier³

1975

Horm Res

View full text Add to dashboard Cite

show abstract

“…Enlargement of the pars intermedia of the pituitary gland after division of the pituitary stalk has been reported in the rat (Uotila, 1939; Barrnett & Greep, 1951), rabbit (Brooks, 1938) and goat (Daniel & Prichard, 1958). None of these authors, however, attempted to compare the volume of the pars intermedia of stalk-sectioned animals with that of normal controls.…”

Section: Introductionmentioning

confidence: 93%

The Pituitary Gland of Normal and Stalk-Sectioned Monkeys With Particular Reference to the Pars Intermedia

Rl¹

1962

Journal of Endocrinology

View full text Add to dashboard Cite

The pars distalis, pars intermedia and infundibular process make up, respectively, 61, 5 and 34% of the volume of the pituitary gland of normal mature female rhesus monkeys. The pars distalis is relatively smaller in immature animals, and larger during pregnancy.Section of the pituitary stalk is followed by a significant increase in the volume of the pars intermedia; the infundibular process always decreases in volume, while the pars distalis shrinks to a lesser and more variable extent.Histological changes in the pars intermedia suggest that cellular hypertrophy, infiltration of atypical cells, and cyst formation all contribute to the increase in volume, and that the changes are at any rate partly degenerative in nature.

show abstract

“…The cold response is blunted in pituitary-stalk operated rats (Uotila 1939) and after PVN-electrolytic lesions (Ishikawa et al 1984). An acute cold exposure rapidly and transiently augments Trh mRNA levels in the PVN, followed by increased TSH in serum and T 4 at a later time (Zoeller et al 1990, Uribe et al 1993.…”

Section: Energy Demands Activate the Hpt Axismentioning

confidence: 98%

“…By the 1980s, the sequence of TSH subunits became available with the isolation of their cDNAs (Fiddes & Goodman 1981, Wondisford et al 1988) and the clinical use of recombinant human TSH (hTSH), which eliminated the health risks associated with the use of contaminated hTSH isolated from post-mortem tissues (Weintraub & Szkudlinski 1999). Physiological support for the existence of the hypothalamic control of pituitary-thyroid function started with the pioneering work of Uotila on pituitary-stalk sections (Uotila 1939) and was further substantiated by complementary approaches such as electrical stimulation, electrolytic lesions of median eminence (ME) or diverse hypothalamic nuclei, administration of hypothalamic extracts, and histological observations under different physiological conditions (Greer 1952, Brown-Grant et al 1957. Diminished basal thyroid activity in rabbits was observed after pituitary-stalk transections had been made, and a piece of wax paper had been placed between sections to eliminate vascular regeneration (Brown-Grant et al 1954).…”

mentioning

confidence: 99%

60 YEARS OF NEUROENDOCRINOLOGY: TRH, the first hypophysiotropic releasing hormone isolated: control of the pituitary–thyroid axis

Joseph‐Bravo

Jaimes-Hoy

Uribe

et al. 2015

Journal of Endocrinology

View full text Add to dashboard Cite

This review presents the findings that led to the discovery of TRH and the understanding of the central mechanisms that control hypothalamus-pituitary-thyroid axis (HPT) activity. The earliest studies on thyroid physiology are now dated a century ago when basal metabolic rate was associated with thyroid status. It took over 50 years to identify the key elements involved in the HPT axis. Thyroid hormones (TH: T 4 and T 3 ) were characterized first, followed by the semi-purification of TSH whose later characterization paralleled that of TRH. Studies on the effects of TH became possible with the availability of synthetic hormones. DNA recombinant techniques permitted the identification of all the elements involved in the HPT axis, including their mode of regulation. Hypophysiotropic TRH neurons, which control the pituitary-thyroid axis, were identified among other hypothalamic neurons which express TRH. Three different deiodinases were recognized in various tissues, as well as their involvement in cell-specific modulation of T 3 concentration. The role of tanycytes in setting TRH levels due to the activity of deiodinase type 2 and the TRH-degrading ectoenzyme was unraveled. TH-feedback effects occur at different levels, including TRH and TSH synthesis and release, deiodinase activity, pituitary TRH-receptor and TRH degradation. The activity of TRH neurons is regulated by nutritional status through neurons of the arcuate nucleus, which sense metabolic signals such as circulating leptin levels. Trh expression and the HPT axis are activated by energy demanding situations, such as cold and exercise, whereas it is inhibited by negative energy balance situations such as fasting, inflammation or chronic stress. New approaches are being used to understand the activity of TRHergic neurons within metabolic circuits. A historical perspective on the hypothalamic control of the thyroid axisThe advancement of any scientific field requires the combination of creative new ideas with the development of technologies and knowledge in related areas; understanding the function of the hypothalamus-pituitarythyroid axis (HPT) is no exception (Figs 1 and 2). Since the end of the 19th century, European physicians and surgeons associated neck swelling (thyroid enlargement, goiter), with iodine deficiency, cretinism, and myxoedema, This paper is part of a thematic review section on 60 years of neuroendocrinology. The Guest Editors for this section were Ashley Grossman and Clive Coen defining hypothyroid conditions. Magnus-Levy (1895) was the first to demonstrate that respiratory metabolism was increased in hyperthyroidism and decreased in myxoedema. Indirect calorimetry allowed measurements of basal metabolic rate (BMR) and the evaluation of thyroid activity in clinical practice (Du Bois & Du Bois 1915, Harris & Benedict 1918. Soon it was recognized that stressful conditions such as fever, acidosis, or starvation modify BMR (Rowe 1920). In 1919, levothyroxine (3,3 0 ,5,5 0 -tetraiodothyronine or T 4 ) was characterized, and then ...

show abstract

On the Role of the Pituitary Stalk in the Regulation of the Anterior Pituitary, With Special Reference to the Thyrotropic Hormone1

Cited by 71 publications

References 0 publications

Interactions between the Pituitary, Thyroid and Adrenal Cortex during Acute Exposure to Cold or to Electric Shocks in the Rat

Interactions between the Pituitary, Thyroid and Adrenal Cortex during Acute Exposure to Cold or to Electric Shocks in the Rat

The Pituitary Gland of Normal and Stalk-Sectioned Monkeys With Particular Reference to the Pars Intermedia

60 YEARS OF NEUROENDOCRINOLOGY: TRH, the first hypophysiotropic releasing hormone isolated: control of the pituitary–thyroid axis

Contact Info

Product

Resources

About