scholarly journals Organization of the hypothalamic-pituitary system: current concepts from immunohistochemical studies.

1976 ◽  
Vol 24 (7) ◽  
pp. 807-815 ◽  
Author(s):  
E A Zimmerman ◽  
J L Antunes
Keyword(s):  
Median Eminence ◽  
Preoptic Area ◽  
Immunoperoxidase Technique ◽  
Posterior Pituitary ◽  
Common Features ◽  
Magnocellular Nuclei ◽  
The Media ◽  
Posterior Pituitary Gland ◽  
Immunohistochemical Studies ◽  
Hypophysial Portal

Immunoperoxidase technique and light microscopy have been used to localize neurosecretory systems for vasopressin, oxytocin and related neurophysins (neurohypophysial peptides)) and gonadotropin-releasing hormone (Gn-RH) in the rhesus monkey brain. All the neurohypophysial peptides were found in the magnocellular nuclei (suproptic and paraventricular) of the hypothalamus and in their projections to the posterior pituitary gland, the zona externa of the median eminence and the organum vasculosum of the lamina terminalis (OVLT). Gn-RH was found in smaller cell bodies which were widely scattered in the hypothalamus. Some of these were found in the media-basal hypothalamus in the infundibular nucleus and lateral and dorsal to it, while others were found in dorsal hypothalamus. Numerous cells were also located in the preoptic area close to the OLVT. Gn-RH-containing fibers projected to the OVLT and the zona externa of the median eminence. The two neurosecretory systems studied have two common features: magnocellular perikarya containing the neurohypophysial peptides and smaller elements containing Gn-RH are found near and appear to terminate around the fine vessels of the OVLT. In addition, cells of both systems send fibers to the hypophysial portal capillary system in the zona externa of the median eminence. Many more vasopressin-than oxytocin-containing fibers end in the entire expanse of the zona externa, where they are mainly concentrated in the anterior and middle parts, while Gn-RH fibers project to all portions.

Vasopressin Concentrations in Hypophysial Portal Plasma: Insignificant Reduction following Removal of the Posterior Pituitary Gland

1981 ◽  
Vol 33 (2) ◽  
pp. 88-90 ◽  
Author(s):  
Larry D. Recht ◽  
Donald L. Hoffman ◽  
Jaya Haldar ◽  
Ann-Judith Silverman ◽  
Earl A. Zimmerman
Keyword(s):  
Pituitary Gland ◽  
Posterior Pituitary ◽  
Portal Plasma ◽  
Posterior Pituitary Gland ◽  
Hypophysial Portal

Disorders of the posterior pituitary gland

2020 ◽  
pp. 2277-2283
Author(s):  
Niki Karavitaki ◽  
Shahzada K. Ahmed ◽  
John A.H. Wass
Keyword(s):  
Median Eminence ◽  
Arginine Vasopressin ◽  
Volume Overload ◽  
Urine Osmolality ◽  
Posterior Pituitary ◽  
Common Cause ◽  
Posterior Pituitary Gland ◽  
Long Acting ◽  
Cranial Diabetes Insipidus ◽  
Inappropriate Antidiuresis

The posterior pituitary produces arginine vasopressin, which has a key role in fluid homeostasis, and oxytocin, which stimulates uterine contraction during birth and ejection of milk during lactation. Cranial diabetes insipidus is the passage of large volumes of dilute urine due to vasopressin deficient synthesis and/or release. The most common cause is lesions of the neurohypophysis or the hypothalamic median eminence damaging the magnocellular neurons. MRI of the neurohypophysis is required to delineate the cause. Mild polyuria can be managed simply by ensuring adequate fluid intake; treatment with the long-acting vasopressin analogue, desmopressin is used for more severe cases. The syndrome of inappropriate antidiuresis is diagnosed when there is hyponatraemia with hypotonic plasma, inappropriate urine osmolality, and urinary sodium more than 20 mmol/litre, together with no evidence of volume overload or hypovolaemia, and normal renal, adrenal, and thyroid function.

Immunocytochemical Localization of Angiotensin II and Vasopressin in Rat Hypothalamus: Evidence for Production in the Same Neuron

1980 ◽  
Vol 59 (s6) ◽  
pp. 57s-60s ◽  
Author(s):  
M. M. Kilcoyne ◽  
D. L. Hoffman ◽  
E. A. Zimmerman
Keyword(s):  
Angiotensin Ii ◽  
Median Eminence ◽  
Antigenic Determinants ◽  
Immunoperoxidase Technique ◽  
Ang Ii ◽  
Magnocellular Neurons ◽  
Paraventricular Nuclei ◽  
Parvocellular Neurons ◽  
Posterior Pituitary Gland ◽  
Vasopressin Precursor

1. By immunoperoxidase technique, immunoreactive angiotensin II (ANG II) was located in the cell bodies of many magnocellular neurons in the supraoptic and paraventricular nuclei of the hypothalamus and their pathways to median eminence and posterior pituitary gland in the rat. 2. Like vasopressin and its neurophysin, but not oxytocin, ANG II was also found in parvocellular neurons in the suprachiasmatic nucleus. 3. Analysis of these peptides in the same magnocellular neurons reveals that ANG II is localized primarily in vasopressin cells. 4. Like vasopressin and its precursor, ANG II is deficient in homozygous Brattleboro rats with diabetes insipidus. 5. In adrenalectomized rats increases in vasopressin and its neurophysin in median eminence are associated with increases in ANG II. 6. The data suggest that the ANG II demonstrated shares antigenic determinants with the vasopressin precursor, or is regulated in a similar way to vasopressin in the same neurons.

DISTRIBUTION OF CORTICOTROPHIN RELEASING FACTOR ACTIVITY WITHIN THE HYPOTHALAMIC-PITUITARY COMPLEX OF RATS AND CATTLE

1977 ◽  
Vol 75 (2) ◽  
pp. 293-303 ◽  
Author(s):  
NAOKI YASUDA ◽  
MONTE A. GREER ◽  
SUSAN E. GREER ◽  
PATRICIA PANTON
Keyword(s):  
Pituitary Gland ◽  
Dose Response ◽  
Median Eminence ◽  
Response Curve ◽  
Posterior Pituitary ◽  
Corticotrophin Releasing Factor ◽  
Pars Nervosa ◽  
Pituitary Glands ◽  
Posterior Pituitary Gland ◽  
Qualitative Similarity

An assay system involving cultured rat adenohypophysial cells from either intact or adrenalectomized donors was used to study the distribution of corticotrophin releasing factor (CRF) activity in the hypothalamic-pituitary complex of rats and cattle. In the rat hypothalamus, CRF activity was most concentrated in the median eminence, but CRF was present in the stalk and the posterior pituitary gland in much higher concentrations than in the median eminence in both species. The dose–response slopes for the median eminence, stalk and pars nervosa of the posterior pituitary gland were parallel to each other, suggesting a qualitative similarity between the CRF activity in these tissues. Rat posterior pituitary glands may also contain another CRF component which has a much flatter dose–response curve, but is detectable in smaller quantities of posterior pituitary tissue than is the other type of CRF.

A CASE REPORT: ECTOPIC POSTERIOR PITUITARY GLAND

2015 ◽  
pp. 120-124
Author(s):  
Thi Ngoc Hien Pham ◽  
Trong Khoan Le
Keyword(s):  
Case Report ◽  
Pituitary Gland ◽  
Key Words ◽  
Median Eminence ◽  
Bright Spot ◽  
Posterior Pituitary ◽  
Pituitary Dwarfism ◽  
Posterior Pituitary Gland ◽  
Ectopic Posterior Pituitary ◽  
Pituitary Bright Spot

Posterior pituitary ectopia refers to an absent normal posterior pituitary bright spot within the sella with ectopic bright signal at another site (such as the median eminence) on T1 weighted images. We describe one case with congenital pituitary dwarfism caused by ectopic posterior pituitary gland. Key words: Ectopic posterior pituitary gland, congenital pituitary dwarfism.

THE RELATION BETWEEN THE HYPOTHALAMIC NEUROSECRETION AND THE CORTICOTROPHIN RELEASE IN EXPERIMENTAL CONDITIONS

1960 ◽  
Vol XXXIV (I) ◽  
pp. 8-18 ◽  
Author(s):  
E. Kivalo ◽  
U. K. Rinne
Keyword(s):  
Paraventricular Nucleus ◽  
Median Eminence ◽  
Supraoptic Nucleus ◽  
Acute Stress ◽  
Neurosecretory Material ◽  
Experimental Conditions ◽  
Hypothalamic Cells ◽  
The One ◽  
Hypophysial Portal ◽  
Acth Release

ABSTRACT Acute stress, chronic stress plus hydration, cortisone treatment, cortisone treatment plus dehydration were used as methods of investigation and the relation between the neurosecretory activity of the hypothalamic supraoptic nucleus and paraventricular nucleus and the neurosecretory material around the hypophysial portal vessels of the median eminence on the one hand and the corticotrophin release on the other hand, has been studied in the rat. Whereas stress stimulates both the activity of the above mentioned cells of the hypothalamus and the ACTH release, stress plus hydration causes a depression of these hypothalamic cells but nevertheless causes a marked ACTH release. Cortisone inhibits the activity of the cells in the supraoptic nucleus and the paraventricular nucleus as well as the ACTH release whereas cortisone plus dehydration causes stimulation but inhibits the ACTH release. In some stress and cortisone treatment groups the variations of the neurosecretory material around the hypophysial portal vessels and of the ACTH release were found to show a correlation. It is concluded that the activity of the cells of the supraoptic nucleus and the paraventricular nucleus and the ACTH release do not seem to have any definite connection, whereas some observations indicate that the neurosecretory material in the region of the median eminence around the hypophysial portal vessels may have some significance in ACTH release.

scholarly journals The Increase in Signaling by Kisspeptin Neurons in the Preoptic Area and Associated Changes in Clock Gene Expression That Trigger the LH Surge in Female Rats Are Dependent on the Facilitatory Action of a Noradrenaline Input

Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 323-335 ◽  
Author(s):  
Bruna Kalil ◽  
Aline B. Ribeiro ◽  
Cristiane M. Leite ◽  
Ernane T. Uchôa ◽  
Ruither O. Carolino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Median Eminence ◽  
Preoptic Area ◽  
Clock Genes ◽  
Third Ventricle ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Lh Surge ◽  
Clock Gene Expression

Abstract In rodents, kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) of the preoptic area are considered to provide a major stimulatory input to the GnRH neuronal network that is responsible for triggering the preovulatory LH surge. Noradrenaline (NA) is one of the main modulators of GnRH release, and NA fibers are found in close apposition to kisspeptin neurons in the RP3V. Our objective was to interrogate the role of NA signaling in the kisspeptin control of GnRH secretion during the estradiol induced LH surge in ovariectomized rats, using prazosin, an α1-adrenergic receptor antagonist. In control rats, the estradiol-induced LH surge at 17 hours was associated with a significant increase in GnRH and kisspeptin content in the median eminence with the increase in kisspeptin preceding that of GnRH and LH. Prazosin, administered 5 and 3 hours prior to the predicted time of the LH surge truncated the LH surge and abolished the rise in GnRH and kisspeptin in the median eminence. In the preoptic area, prazosin blocked the increases in Kiss1 gene expression and kisspeptin content in association with a disruption in the expression of the clock genes, Per1 and Bmal1. Together these findings demonstrate for the first time that NA modulates kisspeptin synthesis in the RP3V through the activation of α1-adrenergic receptors prior to the initiation of the LH surge and indicate a potential role of α1-adrenergic signaling in the circadian-controlled pathway timing of the preovulatory LH surge.

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