HYPOTHALAMO-NEUROHYPOPHYSIAL NEUROSECRETION AFTER THE EXTIRPATION OF VARIOUS ENDOCRINE GLANDS

1963 ◽  
Vol 42 (2) ◽  
pp. 293-299 ◽  
Author(s):  
H. Arko ◽  
E. Kivalo ◽  
U. K. Rinne
Keyword(s):  
Median Eminence ◽  
Vascular System ◽  
Pituitary Hormones ◽  
Bilateral Adrenalectomy ◽  
Neurosecretory Material ◽  
Experimental Conditions ◽  
Paraventricular Nuclei ◽  
Aldehyde Fuchsin ◽  
Hypophysial Portal

ABSTRACT The possible role of the hypothalamo-neurohypophysial system in regulating the release of the anterior pituitary hormones was studied in the rabbit and the rat. Thyroidectomy, gonadectomy and uni- and bilateral adrenalectomy were the experimental conditions used. The neurosecretory material (N. S. M.) was demonstrated by the aldehyde-fuchsin (AF) technique. Distinct differences were not seen in the different groups of rabbits on account of the great variation between individuals. In the rats, the thyroidectomy and gonadectomy groups often had slightly more N. S. M. in the median eminence around the portal vessels than the controls. Slight depletion of N. S. M. in the infundibular process was observed in unilaterally adrenalectomized rats. N. S. M. passing into the portal vascular system showed a tendency to increase. In the bilateral adrenalectomy group, N. S. M. was reduced in the supraoptic and paraventricular nuclei, in the hypothalamo-hypophysial tract and in the infundibular process. However, considerably more numerous neurosecretory nerve fibres passing towards the portal vessels than in the controls were found in the median eminence of this group. The conclusion drawn was that N. S. M. entering the hypophysial portal vessels in the median eminence may be of significance in the regulation of corticotrophin release.

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.

Corticotrophin-releasing peptides in rat hypophysial portal blood after paraventricular lesions: a marked reduction in the concentration of corticotrophin-releasing factor-41, but no change in vasopressin

1990 ◽  
Vol 125 (2) ◽  
pp. 175-183 ◽  
Author(s):  
F. A. Antoni ◽  
G. Fink ◽  
W. J. Sheward
Keyword(s):  
Median Eminence ◽  
Feedback Inhibition ◽  
Portal Blood ◽  
Corticotrophin Releasing Factor ◽  
Paraventricular Nuclei ◽  
Oxytocin Release ◽  
Male Wistar Rats ◽  
Hypophysial Portal ◽  
Supraoptic Nuclei

ABSTRACT Previous data show that corticotrophin-releasing factor-41 (CRF-41), arginine vasopressin (AVP) and oxytocin are released into hypophysial portal blood. It has been presumed that the CRF-41 originates mainly from parvicellular neurones of the paraventricular nuclei (PVN); however, AVP and oxytocin could also be derived as a consequence of preterminal release from magnocellular projections to the neurohypophysis. The latter has been suggested to be the case for AVP as assessed by studies of the median eminence in vitro. Here we have investigated the source of CRF-41, AVP and oxytocin in hypophysial portal blood of adult male Wistar rats 8–10 days after surgical lesioning of the PVN. In PVN-lesioned animals the output of CRF-41 into hypophysial portal blood was reduced by about 90%, and that of oxytocin by about 40%: however, the output of AVP into portal blood was reduced only by about 10%. The release of AVP into portal blood increased after adrenalectomy; this increased release could be returned to normal by treatment with dexamethasone. No change of AVP release occurred after adrenalectomy in animals in which the PVN had been lesioned. These results show (i) that most of the CRF-41 released into hypophysial portal blood is derived from the PVN, (ii) that in PVN-lesioned animals AVP and oxytocin release remains at near normal or 60% of normal respectively, suggesting that a substantial amount of both neuropeptides in portal blood is derived as a consequence of preterminal release from supraoptic nuclei projections in the median eminence, and (iii) that glucocorticoid feedback inhibition of AVP release is exerted at the level of the PVN. Journal of Endocrinology (1990) 125, 175–183

Central catecholaminergic system stimulates secretion of CRH at different sites

1988 ◽  
Vol 255 (4) ◽  
pp. E463-E468 ◽  
Author(s):  
A. Szafarczyk ◽  
V. Guillaume ◽  
B. Conte-Devolx ◽  
G. Alonso ◽  
F. Malaval ◽  
...  
Keyword(s):  
High Performance ◽  
Adrenocorticotropic Hormone ◽  
Female Rats ◽  
Plasma Acth ◽  
Catecholaminergic System ◽  
Paraventricular Nuclei ◽  
6 Hydroxydopamine ◽  
Dramatic Fall ◽  
Hypophysial Portal

To explore a possible differential role of distinct catecholamine (CA) innervation sites in corticotropin-releasing hormone (CRH) secretion, especially under stress conditions, we compared the effects in adult female rats of selective CA denervation of either the whole hypothalamus, by a discrete pharmacological lesion of the ventral noradrenergic ascending bundle [VNAB; 3 micrograms of 6-hydroxydopamine (6-OHDA) in 0.2 microliter of vehicle, bilaterally] or of the paraventricular nuclei (PVN) alone (1 microgram of 6-OHDA in 0.2 microliter of vehicle, bilaterally). Although both procedures induced a similar dramatic fall in norepinephrine and epinephrine concentrations (-55 to -65%) measured by high-performance liquid chromatography in PVN punches, the VNAB lesion, unlike PVN denervation, depleted the median eminence (ME) of both amines (-80%). Concomitantly, the VNAB lesion led to a 97% reduction of the immunoreactive (ir) CRH-41 concentration in the hypophysial portal vessels, associated with a 64% fall in plasma adrenocorticotropic hormone (ACTH), and, in another group, with an 80% inhibition of ether stress-induced ACTH surge. The deletion of CA innervation of the PVN alone reduced irCRH-41 levels in the portal vessels by only 57% and plasma ACTH by 35%. This lesion did not significantly impair stress-induced ACTH release. These results suggest that the CA innervation of the hypothalamus exerts a stimulatory control on CRH-41-secreting neurons not only directly at the perikaryal level but also at other hypothalamic sites of VNAB innervation including peripheral contacts between the terminals of CA and CRH nerves in the external ME.

REGENERATION OF HYPOTHALAMIC NERVE FIBRES AFTER HYPOPHYSECTOMY IN THE GOAT

1970 ◽  
Vol 64 (4) ◽  
pp. 696-704 ◽  
Author(s):  
Peter M. Daniel ◽  
Marjorie M. L. Prichard
Keyword(s):  
Median Eminence ◽  
Distal Part ◽  
Neural Tissue ◽  
Neurosecretory Material ◽  
Pars Tuberalis ◽  
Posterior Lobe ◽  
Nerve Fibres ◽  
Traumatic Lesion ◽  
Paraventricular Nuclei ◽  
Regenerating Nerve

ABSTRACT In goats kept for several months after hypophysectomy it was found that the nerve fibres of the hypothalamo-neurohypophysial tract had regenerated. A posterior lobe-like organ had formed in the neural tissue of the median eminence just proximal to the site where the nerve tract had been severed when the pituitary gland was removed. This new, small, ectopic infundibular process was not only well innervated but also highly vascularised and it contained large amounts of neurosecretory material. Some of the regenerating nerve fibres had grown out from the nerve tract into pars tuberalis and the meninges; many of these nerve fibres carried neurosecretory material. In one goat, not hypophysectomized but with a traumatic lesion of the nerve tract in the pituitary stalk, regenerating nerve fibres had also grown down across the scar of the lesion to reinnervate the degenerate distal part of the nerve tract. Within the hypothalamus the loss of nerve cells was consistently greater in the supraoptic than in the paraventricular nuclei.

Cytochemical characteristics of the neurosecretory cells ofCeylonocotyle scoliocoelium(Trematoda: Digenea)

1981 ◽  
Vol 55 (3) ◽  
pp. 223-229 ◽  
Author(s):  
P. N. Sharma ◽  
A. N. Sharma
Keyword(s):  
Neurosecretory Cells ◽  
Synthetic Activity ◽  
Neurosecretory Material ◽  
Secretory Material ◽  
Β Cells ◽  
A Cells ◽  
Aldehyde Fuchsin

ABSTRACTTwo types of neurosecretory cells (NSC), large a cells and small β cells were detected on the basis of their size and characteristics as shown by aldehyde fuchsin and chrome haematoxylin-phloxin staining. A histochemical survey of the neurosecretory material indicates that it is a glycoprotein. Phosphatases and esterases present in NSC probably help in the transfer of metabolites and their hydrolysis and in the control of secretory material produced in a NSC, while SDH provides the necessary energy for the synthetic activity of the latter. The role of neurosecretion in governing the reproduction of this parasite is discussed.

scholarly journals The role of oxytocin in the regulation of pancreatic function in animals with diabetes mellitus corrected by interval hypoxic training

1997 ◽  
Vol 43 (5) ◽  
pp. 35-38
Author(s):  
A. V. Abramov
Keyword(s):  
Diabetes Mellitus ◽  
Median Eminence ◽  
Secretory Activity ◽  
Large Cell ◽  
Active Role ◽  
Paraventricular Nuclei ◽  
Hypoxic Training ◽  
Study Interval ◽  
High Level

The oxytocin-producing system of the hypothalamus, represented by the supraoptic and posteromedial and anterior large-cell subnuclei of the hypothalamic paraventricular nuclei was studied in Wistar rats. Morphometric methods and detection of oxytocin-producing neurons by indirect immunofluorescence and measurements of immunoreactive oxytocin in the neurons and the median eminence of the hypothalamus were used in the study. Interval hypoxic training corrected the course of experimental diabetes mellitus. Increased production and secretion of oxytocin play an active role in this process. Interval hypoxic training led to an increase of the levels of immunoreactive oxytocin in the neurons of the supraoptic and paraventricular nuclei and in the median eminence of the hypothalamus, whereas the size of neuronal nucleoli remained unchanged. In diabetes mellitus the content of oxytocin in the neurons was less increased, whereas the nucleoli were notably enlarged. Interval hypoxic training caused the most expressed increase of oxytocin content in the neurons and the median eminence of the hypothalamus, which indicated a high level of synthetic and secretory activity of oxytocin-producing system of the hypothalamus.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

The Affiliative Role of Empathy in Everyday Interpersonal Interactions

2019 ◽  
Author(s):  
Whitney R. Ringwald ◽  
Aidan G.C. Wright
Keyword(s):  
Individual Differences ◽  
Structural Equation ◽  
Community Sample ◽  
Empirical Support ◽  
Interpersonal Behavior ◽  
Equation Modeling ◽  
Experimental Conditions ◽  
Student Sample ◽  
Ecological Momentary

Empathy theoretically serves an affiliative interpersonal function by satisfying motives for intimacy and union with others. Accordingly, empathy is expected to vary depending on the situation. Inconsistent empirical support for empathy’s affiliative role may be due to methodology focused on individual differences in empathy or differences between controlled experimental conditions, which fail to capture its dynamic and interpersonal nature. To address these shortcomings, we used ecological momentary assessment to establish typical patterns of empathy across everyday interactions. Associations among empathy, affect, and interpersonal behavior of self and interaction partner were examined in a student sample (N=330), then replicated in a pre-registered community sample (N=279). Multi-level structural equation modeling was used to distinguish individual differences in empathy from interaction-level effects. Results show people are more empathetic during positively-valanced interactions with others perceived as warm and when expressing warmth. By confirming the typically affiliative role of empathy, existing research to the contrary can be best understood as exceptions to the norm.

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