NEUROHUMORAL CONTROL OF THE RELEASE OF ADRENOCORTICOTROPHIC HORMONE

1956 ◽  
Vol 13 (3) ◽  
pp. 229-234 ◽  
Author(s):  
L. MARTINI ◽  
A. de POLI
Keyword(s):  
Ascorbic Acid ◽  
Intraperitoneal Injection ◽  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Portal System ◽  
Posterior Pituitary ◽  
Adrenocorticotrophic Hormone ◽  
Hypophysectomized Rats ◽  
Neurohumoral Control ◽  
Hypophysial Portal

SUMMARY In normal rats intraperitoneal injection of posterior pituitary hormones produces a significant fall in the number of circulating eosinophils and in adrenal ascorbic acid. These effects do not occur in hypophysectomized animals. In hypophysectomized rats bearing hypophysial transplants in the anterior chamber of the eye, both intraperitoneal injection of posterior pituitary hormones and their local application to the eye containing the pituitary graft, also significantly reduce the number of eosinophils and the amount of ascorbic acid in the adrenals. These results are consistent with the hypothesis that the posterior pituitary hormones act as humoral transmitting agents which, released by the hypothalamus into the hypophysial portal system, can activate the anterior pituitary to discharge ACTH.

THE MAINTENANCE OF LACTATION IN THE RAT AFTER HYPOPHYSIAL ANTERIOR LOBECTOMY DURING PREGNANCY

1961 ◽  
Vol 22 (4) ◽  
pp. 403-408 ◽  
Author(s):  
A. T. COWIE ◽  
J. S. TINDAL
Keyword(s):  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Anterior Lobe ◽  
Milk Secretion ◽  
Adrenocorticotrophic Hormone ◽  
Milk Ejection ◽  
Growth Indices ◽  
Partial Restoration ◽  
Hypophysectomized Rats ◽  
Milk Ejection Reflex

SUMMARY Experiments to determine the pituitary hormones necessary for the maintenance of lactation in the rat in the absence of either the anterior lobe of the pituitary or the entire pituitary are described. The anterior pituitary or the whole of the pituitary was removed on the 12th day of pregnancy and prolactin (25 i.u. twice daily) plus adrenocorticotrophic hormone (ACTH) (2 i.u./day) was given to the animals from parturition to the 10th day of lactation inclusive. The lactational performances of the two operated groups of rats, as judged by the litter-growth indices, were 53% (anterior lobectomy) and 43% (hypophysectomy) of normal. The milk-ejection reflex was completely restored in the anterior-lobectomized rats by the time of parturition, but the hypophysectomized rats required a further 2 days before milk ejection appeared to be normal. Our experiments confirm that prolactin and ACTH are two important factors in the maintenance of milk secretion in the rat. Since only partial restoration was achieved, however, it is clear that other factors, presumably of anterior-pituitary origin, are required for the full restoration of lactation.

ON THE MECHANISM OF THE ADRENAL GLAND RESPONSE TO ADRENOCORTICOTROPHIC HORMONE IN HYPOPHYSECTOMIZED RATS

1965 ◽  
Vol 50 (1) ◽  
pp. 55-64 ◽  
Author(s):  
M. Staehelin ◽  
P. Barthe ◽  
P. A. Desaulles
Keyword(s):  
Ascorbic Acid ◽  
Adrenal Gland ◽  
Acid Output ◽  
Adrenocorticotrophic Hormone ◽  
Considerable Time ◽  
Corticosterone Secretion ◽  
Metabolic Block ◽  
Hypophysectomized Rats ◽  
Dose Dependent

ABSTRACT The adrenal gland response to natural or synthetic adrenocorticotrophic hormone was studied at various periods after hypophysectomy. Adrenal ascorbic acid depletion was observed following the administration of ACTH at all intervals up to 10 days. In contrast, the capacity to respond to ACTH by an increase in corticosterone secretion was rapidly lost. Experiments with rat adrenal slices in vitro showed that the capacity to form corticosteroids following the addition of ACTH or 3′,5′-cyclic-AMP is rapidly lost after hypophysectomy, but that the adrenal slices are still capable of producing corticosterone if NADP and glucose-6-phosphate are added to the medium. It is concluded that the adrenal gland is still capable of responding to the action of ACTH for a considerable time after hypophysectomy, but that due to a metabolic block prior to the formation of NADPH, the adrenal is no longer capable of reacting by a further increase in corticosterone production. In addition, it was found that the effects of ACTH on blood flow and ascorbic acid output were parallel. Both effects were dose-dependent, but independent of any concomitant corticosterone secretion, and persisted during the whole period studied after hypophysectomy.

Toward Multifactorial Hypothalamic Regulation of Anterior Pituitary Hormone Secretion

Physiology ◽  
1999 ◽  
Vol 14 (2) ◽  
pp. 54-58
Author(s):  
W. R. Crowley
Keyword(s):  
Neuropeptide Y ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Pituitary Hormones ◽  
Gonadotropin Releasing Hormone ◽  
Pituitary Hormone ◽  
Anterior Pituitary Hormone ◽  
Hypothalamic Hormones ◽  
Hypothalamic Regulation ◽  
Hypophysial Portal

The hypothalamus regulates the secretion of anterior pituitary hormones via release of releasing hormones into the hypophysial portal vasculature. Additional neuromessengers act at the pituitary to modulate responses to the hypothalamic hormones. For example, neuropeptide Y enhances the effect of gonadotropin-releasing hormone and the response to the prolactin-inhibiting hormone dopamine.

Panhypopituitarism

2019 ◽  
pp. 234-238
Author(s):  
Diane Donegan ◽  
Irina Bancos
Keyword(s):  
Growth Hormone ◽  
Luteinizing Hormone ◽  
Anterior Pituitary ◽  
Follicle Stimulating Hormone ◽  
Premature Death ◽  
Cardiovascular Complications ◽  
Pituitary Hormones ◽  
Posterior Pituitary ◽  
Oral Ectoderm ◽  
Neural Ectoderm

Hypopituitarism is defined as a deficiency in 1 or more pituitary hormones. The pituitary gland is composed of the anterior pituitary, which originates from an invagination of the oral ectoderm and forms the Rathke pouch, and the posterior pituitary, which is derived from the neural ectoderm of the diencephalon. The anterior pituitary is composed of 5 types of hormone-producing cells: Somatotrophs produce growth hormone; gonadotrophs, follicle-stimulating hormone and luteinizing hormone; thyrotrophs, thyrotropin; 4 lactotrophs, prolactin; and corticotrophs, corticotropin. Identification of hypopituitarism is important because of its association with premature death due to respiratory and cardiovascular complications.

Diabetes insipidus from sarcoidosis confined to the posterior pituitary

1997 ◽  
pp. 514-519 ◽  
Author(s):  
KC Loh ◽  
A Green ◽  
PA Fitzgerald ◽  
N Weidner ◽  
JB Tyrrell ◽  
...  
Keyword(s):  
Diabetes Insipidus ◽  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Pulmonary Sarcoidosis ◽  
Complete Regression ◽  
Posterior Pituitary ◽  
Pituitary Mass ◽  
Laboratory Investigations ◽  
New Onset

A young white man with new-onset central diabetes insipidus was discovered to have a posterior pituitary mass on magnetic resonance imaging. No other radiological abnormalities were noted in the anterior pituitary, infundibulum or hypothalamus. No other endocrinopathies were present: laboratory investigations showed normal basal concentrations of anterior pituitary hormones, including prolactin. The patient was suspected to have sarcoidosis affecting the posterior pituitary, because of the discovery of pulmonary sarcoidosis during his diagnostic evaluation. His symptoms of polydipsia and polyuria responded promptly to intranasal administration of 1-desamino-8-D-arginine vasopressin (DDAVP). The patient demonstrated complete regression of the posterior pituitary mass after a course of corticosteroid therapy. However, his diabetes insipidus persisted and he continues to need DDAVP treatment, currently at 12 months of follow-up. The resolution of the neurohypophysial mass was compatible with the diagnosis of pituitary sarcoidosis and this precluded the need for a transsphenoidal biopsy or surgery.

THE PREPARATION OF SHEEP GROWTH HORMONE

1963 ◽  
Vol 26 (2) ◽  
pp. 259-263 ◽  
Author(s):  
A. L. C. WALLACE ◽  
K. A. FERGUSON
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Deae Cellulose ◽  
Pituitary Hormones ◽  
Starch Gel Electrophoresis ◽  
Epiphysial Cartilage ◽  
Pituitary Glands ◽  
Hypophysectomized Rats ◽  
Starch Gel ◽  
Main Components

SUMMARY Growth hormone has been prepared from sheep pituitary glands by chromatography of a simple buffer extract on DEAE-cellulose. The preparation appears to be free of other anterior pituitary hormones but shows two main components when analysed by starch gel electrophoresis. These components appear similar to those present in standard preparations of ox growth hormone. Sheep growth hormone prepared by this method is not significantly less active than purified ox growth hormone when compared by the tibial-epiphysial cartilage response in hypophysectomized rats.

HORMONAL HYPERTENSION RESULTING FROM PITUITARY IMBALANCE

1965 ◽  
Vol 43 (2) ◽  
pp. 269-278 ◽  
Author(s):  
John Hunter ◽  
R. E. Haist
Keyword(s):  
Blood Pressure ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Posterior Part ◽  
Pituitary Hormones ◽  
Posterior Pituitary ◽  
Blood Pressure Elevation ◽  
Arterial Blood ◽  
Target Organs ◽  
Intact Rats

The removal of the posterior part of the pituitary gland in the rat leads to an elevation in blood pressure. The production of an anterior–posterior pituitary imbalance in hypophysectomized animals by the administration of certain hormones of target glands influenced by the anterior pituitary (thyroxine, testosterone, cortisone (TTC)) also produces an increase in mean arterial blood pressure. In the intact animal, too, the administration of the hormones of the target organs (TTC) will lead to an elevation of blood pressure, and 1 week after the cessation of this treatment the blood pressure is as high or higher than at the end of the administration period. Administration of anterior pituitary hormones TSH, LH, and ACTH both in hypophysectomized and in intact rats also produced elevations in blood pressure. In two female dogs, administration of pituitary target-organ hormones (TTC) consistently produced an elevation of blood pressure associated with a direct effect of the injected hormones, followed by a depression of blood pressure below previous resting values after hormone withdrawal, presumably because of an associated inhibition of anterior pituitary effects. When certain hormones of the posterior pituitary gland are administered along with TTC, in both hypophysectomized and intact rats, the blood pressure elevation is not as great as with TTC alone, though, by themselves, the posterior pituitary factors caused some elevation in blood pressure. It is concluded that an imbalance between the influences of the anterior and posterior parts of the pituitary gland can lead to a significant elevation in blood pressure. It seems likely that, depending on the dose, the effects observed after the injection of the agent is discontinued may be due to persistence of the action of the agent or, in some instances, to inhibition of the activity of part of the pituitary gland.

ROLE OF THE PITUITARY–ADRENOCORTICAL SYSTEM IN THE STRESS-INDUCED BLOOD PLATELET FLUCTUATION

1966 ◽  
Vol 44 (4) ◽  
pp. 589-596
Author(s):  
S. Renaud ◽  
J. G. Latour
Keyword(s):  
Adrenal Insufficiency ◽  
Blood Platelet ◽  
Pituitary Hormones ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
Surgical Interventions ◽  
Platelet Level ◽  
Hypophysectomized Rats ◽  
Adrenocortical System

The blood platelet fluctuation observed after surgical interventions and reproduced here in the rat is apparently induced, partly or totally, by the reactions of the pituitary–adrenocortical axis to stress. The stress-induced platelet fluctuation could be the result of a certain adrenal insufficiency, since it can be elicited by simple adrenalectomy and completely prevented in immobilized but otherwise normal rats by hydrocortisone administered solely at the time of the immobilization. The thrombocytosis which occurs from 5 to 8 days after the stress appears to be dependent on the posterior pituitary hormones, since in hypophysectomized rats it could be reproduced only when posterior lobe or whole pituitary extracts were injected or when the posterior lobe had reorganized 26 days after the hypophysectomy. The potassium and sodium concentrations in serum did not seem to exert any influence on the blood platelet level under our conditions.

THE PRESENCE OF ADRENOCORTICOTROPHIC HORMONE IN THE PITUITARY OF THE ARCTIC COD, GADUS MORHUA L.

1960 ◽  
Vol 21 (3) ◽  
pp. 295-301 ◽  
Author(s):  
A. D. WOODHEAD
Keyword(s):  
Ascorbic Acid ◽  
Gadus Morhua ◽  
Adrenal Weight ◽  
The Arctic ◽  
Adrenocorticotrophic Hormone ◽  
Arctic Cod ◽  
Hypophysectomized Rats ◽  
Positive Results

SUMMARY The presence of an adrenocorticotrophic hormone (ACTH) has been demonstrated in the pituitary of the Arctic cod, Gadus morhua L. using standard assays with rats. Positive results were obtained in assays by the Sayers method of measuring the depletion of adrenal ascorbic acid in hypophysectomized rats, and by that of maintenance of adrenal weight, also in hypophysectomized rats. Adrenocorticotrophic activity was present in samples from both immature and mature cod. A tentative calculation suggested that the adrenocorticotrophic potency of one sample of cod pituitary was approx. 3·5 mu. ACTH/mg.

Sign in / Sign up

Export Citation Format

Share Document