Chemical Isolation and Determination of Catecholamines in the Median Eminence and Pars Nervosa of the Rat and Horse

1969 ◽  
Vol 5 (3-4) ◽  
pp. 140-148 ◽  
Author(s):  
Toshinaga Iwata ◽  
Susumu Ishii
Keyword(s):  
Median Eminence ◽  
Pars Nervosa

ADENOHYPOPHYSEAL LH CONTENT IN NORMAL, ANDROGEN-STERILIZED AND PROGESTERONE-PRIMED STERILE FEMALE RATS

1962 ◽  
Vol 39 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Roger A. Gorski ◽  
Charles A. Barraclough
Keyword(s):  
Ascorbic Acid ◽  
Electrical Stimulation ◽  
Quantitative Determination ◽  
Median Eminence ◽  
Hypothalamic Stimulation ◽  
Female Rats ◽  
Rat Pituitary ◽  
Gland Content ◽  
Stimulation Of

ABSTRACT We have previously suggested that the failure of the androgen-sterilized, persistent-oestrous rat to ovulate, following electrical stimulation of the median eminence structures of the hypothalamus, is due to an insufficiency in adenohypophyseal LH concentration. Using the ovarian ascorbic acid technique for quantitative determination of pituitary LH content, the present studies have demonstrated that the sterile rat pituitary gland contains one-third the LH content of the normal prooestrous gland. Furthermore, not only does progesterone priming of this persistent-oestrous rat result in a 75 % increase in LH concentration, but on hypothalamic stimulation sufficient LH is released to induce ovulation. The decrease in LH concentration which accompanies ovulation in the progesterone-primed, sterile rat is approximately 45 % of the total gland content as compared with a 51 % decrease in pituitary content in the normal cyclic rat.

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.

CORTICOTROPHIC STUDIES WITH ASPIRIN

1962 ◽  
Vol 24 (1) ◽  
pp. 7-16 ◽  
Author(s):  
E. LEONG WAY ◽  
JOAN TAYLOR ◽  
L. J. OLD ◽  
R. GEORGE
Keyword(s):  
Ascorbic Acid ◽  
Antidiuretic Hormone ◽  
Median Eminence ◽  
Marked Reduction ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Pars Nervosa

SUMMARY The effect of aspirin in reducing adrenal ascorbic acid in Sprague—Dawley rats was studied using each animal as its own control. The response to aspirin was blocked by lesions in the region of the median eminence and by hypophysectomy. Removal of the pars nervosa also resulted in depression of the response in the majority of cases. In normal animals the dose of aspirin which produced marked reduction of adrenal ascorbic acid failed to promote antidiuresis. It was concluded that pituitary-adrenal activation by aspirin is mediated via the hypothalamus and that release of the antidiuretic hormone is not essential for this effect.

Neurohypophyseal hormones in the avian median eminence and pars nervosa

1962 ◽  
Vol 2 (5) ◽  
pp. 433-440 ◽  
Author(s):  
Susumu Ishii ◽  
Tetsuya Hirano ◽  
Hideshi Kobayashi
Keyword(s):  
Median Eminence ◽  
Neurohypophyseal Hormones ◽  
Pars Nervosa

scholarly journals Hydrocephalus-Induced Changes in the Endocrine Hypothalamus of the Hamster

2017 ◽  
Vol 5 (2) ◽  
pp. 45-60
Author(s):  
Gilberto M. Azzi
Keyword(s):  
Pituitary Gland ◽  
Median Eminence ◽  
Brain Slices ◽  
Periventricular White Matter ◽  
Endocrine Hypothalamus ◽  
Endogenous Peroxidase ◽  
Analysis System ◽  
Induced Changes ◽  
Supraoptic Nuclei

Hydroceplanllus-induced changes in intracranial pressure (ICP), ventricular size, periventricular edema and erytlirocyte density(ED), median eminence thickness, and pituitary gland morphology were determined in adult female hamsters (Mesocricetus auratus). Hydrocephalus (HC) was induced by intracisternal injection of kaolin (0.03 ml, 50 mg/ml saline); controls did not receive kaolin. Animais were chronically cannulated and ICP measured periodically (Camino V 420). At selecied times control and treated animals were decapitated, brains removed with the pituitary gland attached and fixed by immersion in formalin. Coronal brain slices containing the paraventricular nuclei (PVN), supraoptic nuclei (SON), suprachiosmatic nuclei (SCN), subfornical organ (SFO) and median eminence (ME) were prepared using a rodent brain matrix slicer and ventricular arca was quantitated by morphometric analysis (Jandel Video Analysis System). Samples were collected from the cortex and periventricular white matter (containing the PVN, SON, and SCN) and the median eminence. The whole pituitary gland was also collected for determination of specific gravity by linear density column method. Erythrocyte Densiry was assessed by immersing hydrocephalic brain slices containing the select nuclei in Karnoviskys fixative on day 9 post HC induction, and in simerythrocytes stained for endogenous peroxidase by tretramethyl benzidine cylochemistry to facilitate visualization. Previous studies in our laboratory have establislied that HC can result in alterations in estrous cycle, water balance, food intake and growth. The result in part from decrease perfusion of the endocrine liypothalamus and pituitary gland, edema and pressure-induced changes in the median eminence structures.

THE STRUCTURE OF THE RABBIT NEUROHYPOPHYSIS

1953 ◽  
Vol 9 (1) ◽  
pp. 30-41 ◽  
Author(s):  
E. VAZQUEZ-LOPEZ
Keyword(s):  
Median Eminence ◽  
Vessel Wall ◽  
Vascular System ◽  
The Body ◽  
Sensory Organ ◽  
Perivascular Spaces ◽  
Secretory Function ◽  
Nerve Fibres ◽  
Pars Nervosa ◽  
Nerve Tracts

1. The rabbit neurohypophysis is composed of nerve fibres and their endings, of neuroglia and microglia, and of a vascular system with reticulin fibres spreading in perivascular spaces. 2. The nerve tracts in the pars nervosa lie in the wide areas between the perivascular spaces, but the axons leave the tracts to run their terminal courses within these spaces. 3. The axons terminate in complicated giant bulbs and menisci. 4. The neuroglia lies in the same areas as the nerve tracts. Many neuroglial processes cross the perivascular spaces and end in attachment to the vessel wall. There are no important connexions between neuroglial cells and axon endings. 5. There is no specific type of neuroglia peculiar to the neurohypophysis. The morphology of the neuroglial cells in the median eminence and in the stalk is different from that of the neuroglial cells in the pars nervosa. 6. Morphologically, the neurohypophysis appears to be a sensory organ, similar to the chemo-receptors and pressor-receptors existing in other parts of the body. If it has a secretory function as well, then the secretion may occur at the giant terminations of the nerves, perhaps by a process of rupture of these formations.

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