Metabolic Clearance and Secretion Rates of TSH Following Adrenalectomy and Corticosterone Administration in the Rat

Marceau, H.; Delgado, Alfonso; Macintosh-Hardt, Barbara; Fortier, Claude

doi:10.1210/endo-90-4-973

Cited by 10 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the observations of Marceau et al (1972) that adrenalectomy or chronic treatment with corticosterone fails to alter the secretion rate of TSH. Consequently, our results do not support the hypothesis of a necessary competition either between ACTH and TSH, or between the corresponding hypothalamic factors CRF and TRF, hypothesis which would imply a decreased ability of the adrenalectomized animal to secrete TSH.…”

Section: Discussionsupporting

confidence: 93%

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

Self Cite

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: 93%

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…This difference may be due to greater sensitivity of the pituitary to TRH after longer treatment. Our results accord well with those of Marceau et al (1972), who demonstrated that treat¬ ment of rats with corticosteroids for 14 days produced no significant change in TSH secretion when compared to controls.…”

Section: Discussionsupporting

confidence: 92%

Augmented Secretion of TSH in Response to TRH After Pre-Treatment With Dexamethasone for Six Days in Rats

Ranta

1976

Acta Endocrinologica

View full text Add to dashboard Cite

Serum TSH and corticosterone concentrations were measured in rats given TRH or exposed to short-term cold, as well as in intact rats, after pretreatment with dexamethasone for six days at two different dose levels (25 and 250 \g=m\g/100g body weight). Both doses increased the secretion of TSH in response to TRH whereas cold-induced TSH secretion was not modified by pre-treatment with dexamethasone. In intact rats serum TSH levels did not differ significantly from controls. In all experiments the steroid blocked ACTH secretion. It was also found that administration of TRH produced a rise in serum corticosterone concentrations. Our results support the view that dexamethasone given for six days facilitates TRH stimulation of the pituitary whilst simultaneously inhibiting the secretion of TRH in response to cold.The effect of glucocorticoids on TSH secretion in the rat has been a subject of considerable interest and confusion. Short-term pre-treatment with dexametha¬ sone has been shown to increase the release of TSH from the pituitary in re¬ sponse to TRH (Sakiz 8c Guillemin 1965) and to inhibit cold-induced rises in serum TSH (Ducommun et al. 1966). Other investigators have, however, been unable to confirm these findings (Wilber 8c Utiger 1969;Fortier et al. 1970;Koch et al. 1972). In the light of recent research this inconsistency of results can be understood. It has been shown that the effect of dexamethasone on the secretion of TSH is highly dependent on time schedules used (Brown 8c Hedge 1973Ranta 1975). It is, however, not known how dexamethasone affects 710 The Institute of Physiology, University of Helsinki

show abstract

“…Pituitary TSH concentration, reveals the equilibrium between the hormonal synthesis and secretion rates (MARCEAU et al, 1972). In the present work, we have observed that following adrenalectomy, the cell area is greatly expanded, a parameter that reflects an increase in the pituitary TSH content (CHILDS, 1983).…”

Section: Discussionsupporting

confidence: 52%

“…The uncoupling of TSH storage and secretion observed in different experimental conditions (MARCEAU et al, 1972), does not allow us to employ the pituitary TSH content as an index of secretory activity. However the histological picture of activation that we have observed in the thyroid glands after adrenalectomy, could indicate an enhanced TSH secretion rate, data coincident with the observations made by MITSUMA and NOGIMORI (1982) 1 week after the adrenalectomy.…”

Section: Discussionmentioning

confidence: 99%

“…An inverted relation between ACTH and TSH secretion was first established based on an inhibition of TSH secretion coupled to an augmented ACTH secretion, following non specific stress (MARCEAU et al, 1972). Similarly, PAMENTER and HEDGE (1980) suggested that as the corticosteroid concentration increases, it exerts a greater feedback inhibition of ACTH secretion, which, via the inverse relationship, would favour TSH secretion.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of the Pituitary‐Thyroid Axis in Bilaterally Adrenalectomized or Adrenal Transplanted Rats

Sarrı́a

Losada

Oliver

1994

Anat Histol Embryol

View full text Add to dashboard Cite

The percentage, distribution, shape, intensity of staining and morphometrical parameters of the pituitary TSH immunoreactive cells and the histological features of the thyroid glands, were compared between adult rats with intact adrenals, without adrenals and biadrenalectomized animals with neonatal adrenal grafts. After the removal of the adrenal glands, TSH immunoreactive cells increased in percentage and exhibited a higher complexity of the cellular outline, than that of the intact animals. The nuclear, cytoplasmic and cell areas were significantly increased. However the bigger enhancement of the cytoplasmic area relative to the nuclear area, produced a decrease in the nuclear/cell area ratio. The thyroid glands showed some histological evidences of activation. After the transplantation of neonatal adrenal glands to adult rats, several adrenocortical nodules were present in the lumen of the small bowel segment. These adrenal masses induced a great decrease in the TSH cell area, which coupled with a smaller but significant variation of the nuclear area, led to an increase in the nuclear/cell area ratio relative to that observed in adrenalectomized animals. In addition, the distribution, shape and intensity of the immunoreactive material was similar to that observed in intact animals. In this experimental group, thyroid histology was observed to be similar to that of the intact animals.

show abstract

Metabolic Clearance and Secretion Rates of TSH Following Adrenalectomy and Corticosterone Administration in the Rat

Cited by 10 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

Augmented Secretion of TSH in Response to TRH After Pre-Treatment With Dexamethasone for Six Days in Rats

Analysis of the Pituitary‐Thyroid Axis in Bilaterally Adrenalectomized or Adrenal Transplanted Rats

Contact Info

Product

Resources

About