Interrelationship of CSF, Hypophysial Portal Vessels, and Hypothalamus and their Role in the Regulation of Anterior Pituitary Function1

2015 ◽  
pp. 71-79
Author(s):  
John C. Porter ◽  
Nira Ben-Jonathan ◽  
Charles Oliver ◽  
Robert L. Eskay ◽  
Alan J. Winters
Keyword(s):  
Anterior Pituitary ◽  
Hypophysial Portal

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.

scholarly journals The effects of hypophysial portal plasma on the content of immunoreactive growth hormone in the anterior pituitary

1970 ◽  
Vol 206 (2) ◽  
pp. 243-256 ◽  
Author(s):  
M. G. Buse ◽  
J. D. Fulmer ◽  
P. C. Kansal ◽  
W. C. Worthington
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Portal Plasma ◽  
Hypophysial Portal

scholarly journals 60 YEARS OF NEUROENDOCRINOLOGY: MEMOIR: Harris' neuroendocrine revolution: of portal vessels and self-priming

2015 ◽  
Vol 226 (2) ◽  
pp. T13-T24 ◽  
Author(s):  
George Fink
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Portal Blood ◽  
Endocrine Disorders ◽  
Experimental Proof ◽  
Chemical Substances ◽  
Major Interest ◽  
The Brain ◽  
Hypophysial Portal

Geoffrey Harris, while still a medical student at Cambridge, was the first researcher (1937) to provide experimental proof for the then tentative view that the anterior pituitary gland was controlled by the CNS. The elegant studies carried out by Harris in the 1940s and early 1950s, alone and in collaboration with John Green and Dora Jacobsohn, established that this control was mediated by a neurohumoral mechanism that involved the transport by hypophysial portal vessel blood of chemical substances from the hypothalamus to the anterior pituitary gland. The neurohumoral control of anterior pituitary secretion was proved by the isolation and characterisation of the ‘chemical substances’ (mainly neuropeptides) and the finding that these substances were released into hypophysial portal blood in a manner consistent with their physiological functions. The new discipline of neuroendocrinology – the way that the brain controls endocrine glands andvice versa– revolutionised the treatment of endocrine disorders such as growth and pubertal abnormalities, infertility and hormone-dependent tumours, and it underpins our understanding of the sexual differentiation of the brain and key aspects of behaviour and mental disorder. Neuroendocrine principles are illustrated in this Thematic Review by way of Harris' major interest: hypothalamic–pituitary–gonadal control. Attention is focussed on the measurement of GnRH in hypophysial portal blood and the role played by the self-priming effect of GnRH in promoting the onset of puberty and enabling the oestrogen-induced surge or pulses of GnRH to trigger the ovulatory gonadotrophin surge in humans and other spontaneously ovulating mammals.

THE RESPONSIVENESS OF THE ANTERIOR PITUITARY GLAND TO LUTEINIZING HORMONE RELEASING FACTOR IN RATS EXPOSED TO CONSTANT LIGHT

1975 ◽  
Vol 65 (3) ◽  
pp. 439-445 ◽  
Author(s):  
G. FINK
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Constant Light ◽  
Blood Samples ◽  
Portal Vessel ◽  
Readily Releasable Pool ◽  
The Mean ◽  
Hypophysial Portal

SUMMARY The responsiveness of the anterior pituitary gland to synthetic luteinizing hormone releasing factor (LH-RF) was tested in rats exposed to constant light. At a dosage of 50 ng LH-RF/ 100 g body wt the mean maximal increments in plasma LH and FSH were similar to those at 10.00 h of pro-oestrus. The increments in the plasma gonadotrophins at dosages of 500 and 1000 ng LH-RF/100 g body wt did not differ significantly from those at 250 ng LH-RF/ 100 g body wt. These findings suggest that, in contrast to rats which exhibit regular oestrous cycles, the preovulatory (post-coital) release of LH in rats exposed to constant light may depend almost entirely on the release of a relatively large amount of LH-RF into hypophysial portal vessel blood. Whereas in pro-oestrous animals a relatively small fraction of the readily releasable pool of LH is released during the spontaneous preovulatory surge, in rats exposed to constant light most releasable LH appears to be discharged during the reflex preovulatory surge of this hormone. The concentrations of radioimmunoassayable FSH in blood samples withdrawn before the injection of LH-RF support the view that FSH secretion in the rat is increased by constant exposure to light.

Prolactin in cerebrospinal fluid increases the synthesis and release of hypothalamic γ-aminobutyric acid

1985 ◽  
Vol 106 (3) ◽  
pp. 323-328 ◽  
Author(s):  
V. Locatelli ◽  
J. A. Apud ◽  
G. A. Gudelsky ◽  
D. Cocchi ◽  
C. Masotto ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Feedback System ◽  
Aminobutyric Acid ◽  
Male Rats ◽  
Acid Decarboxylase ◽  
Plasma Prolactin ◽  
Portal Plasma ◽  
Loop Feedback ◽  
The Mean ◽  
Hypophysial Portal

ABSTRACT The effect of intracerebroventricularly (i.v.t.)-injected rat prolactin (2 μg/rat) on the function of tuberoinfundibular γ-aminobutyric acid (GABA)ergic neurones was assessed in adult male rats by measuring the activity of glutamic acid decarboxylase (GAD) in the mediobasal hypothalamus (MBH) and the concentrations of GABA in hypophysial portal plasma and in the anterior pituitary gland. Fourteen hours after i.v.t. injection of rat prolactin the activity of GAD in the MBH was significantly (P <0·05) increased and it remained elevated for at least 16 h after injection. The mean concentrations of GABA in hypophysial portal plasma and in the anterior pituitary were twice those found in vehicle-treated controls 16 h after administration of rat prolactin; no significant effects were observed at earlier time-periods. A significant (P <0·01) and long-lasting decrease in endogenous plasma prolactin concentrations was detected 2 h after the i.v.t. injection of rat prolactin and the concentrations remained suppressed for up to 16 h. The present results are consistent with the concept that the activity of tuberoinfundibular GABAergic neurones is regulated, at least in part, by circulating prolactin. The ability of prolactin to accelerate the synthesis and release of GABA in the MBH might constitute a short loop feedback system by which the hormone regulates its own secretion. J. Endocr. (1985) 106, 323–328

DOPA Accumulates in the Hypothalamic-Hypophysial Portal Vessels and Is Taken into the Anterior Pituitary of NSD-1015-Treated Rodents

1992 ◽  
Vol 55 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Nancy Telford ◽  
Patrick C. May ◽  
Yagya N. Sinha ◽  
John C. Porter ◽  
Caleb E. Finch
Keyword(s):  
Anterior Pituitary ◽  
Hypophysial Portal

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.

Sites of Insulin Action Using Ferritin Labeling

1971 ◽  
Vol 29 ◽  
pp. 540-541
Author(s):  
Burton B. Silver ◽  
Ronald S. Nelson
Keyword(s):  
Electron Microscopy ◽  
Binding Sites ◽  
Anterior Pituitary ◽  
Insulin Action ◽  
Diabetic Rats ◽  
Insulin Antibody ◽  
Fat Pad ◽  
Target Organs ◽  
Uranium Salts ◽  
Sugar Levels

Some investigators feel that insulin does not enter cells but exerts its influence in some manner on the cell surface. Ferritin labeling of insulin and insulin antibody was used to determine if binding sites of insulin to specific target organs could be seen with electron microscopy.Alloxanized rats were considered diabetic if blood sugar levels were in excess of 300 mg %. Test reagents included ferritin, ferritin labeled insulin, and ferritin labeled insulin antibody. Target organs examined were were diaphragm, kidney, gastrocnemius, fat pad, liver and anterior pituitary. Reagents were administered through the left common carotid. Survival time was at least one hour in test animals. Tissue incubation studies were also done in normal as well as diabetic rats. Specimens were fixed in gluteraldehyde and osmium followed by staining with lead and uranium salts. Some tissues were not stained.

Sign in / Sign up

Export Citation Format

Share Document