scholarly journals Immunohistochemical localization of hypothalamic hormones.

1976 ◽  
Vol 24 (7) ◽  
pp. 864-871 ◽  
Author(s):  
G Pelletier ◽  
R Leclerc ◽  
D Dubé
Keyword(s):  
Endocrine Cells ◽  
Area Postrema ◽  
Secretory Granules ◽  
Subcommissural Organ ◽  
Immunohistochemical Localization ◽  
Nerve Endings ◽  
Immunoperoxidase Technique ◽  
Luteinizing Hormone Releasing Hormone ◽  
Lh Rh ◽  
The Brain

Using an immunoperoxidase technique at the light and electron microscope levels, the localization of somatostatin and luteinizing hormone-releasing hormone (LH-RH) has been performed in the brain, as well as the pancreas and stomach. The following generalizations may be drawn on the localization of LH-RH and somatostatin. (a) LH-RH and somatostatin are contained in axons and nerve endings of the median eminence and organum vasculosum of the lamina terminalis. (b) LH-RH and somatostatin are present in different nerve endings. (c) In the subcommissural organ, subfornical organ and area postrema, the two neurohormones are present in the cytoplasm of ependyman and subependymal cells. (d) In the endocrine pancreas and gastric mucosa, somatostatin is localized within the secretory granules of specific endocrine cells.

scholarly journals Receptors for luteinizing hormone-releasing hormone.

1978 ◽  
Vol 26 (7) ◽  
pp. 542-544 ◽  
Author(s):  
L A Sternberger
Keyword(s):  
Luteinizing Hormone ◽  
Secretory Granules ◽  
Immunocytochemical Staining ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
High Affinity ◽  
Strong Staining ◽  
Lh Rh

Antisera to luteinizing hormone-releasing hormone (LH-RH) confer on Araldite sections of occasional rat pituitaries moderate immunocytochemical staining to the large secretory granules of gonadotrophs. Treatment of the sections with LH-RH before anti-LH-RH yields strong staining in all animals, irrespective of presence or absence of staining without pretreatment. This enhancement of staining is specific for LH-RH and is a high affinity, saturable reaction. Staining with or without LH-RH pretreatment is absent when anti-LH-RH absorbed with insolubilized LH-RH is used. Staining is inhibited by carboxyterminally-deficient LH-RH, unaffected by aminoterminally deficient LH-RH.

EFFECTS OF LUTEINIZING HORMONE RELEASING HORMONE ON THE ULTRASTRUCTURE OF GONADOTROPHS IN THE FOETUS OF THE RHESUS MONKEY NEAR TERM

1977 ◽  
Vol 74 (3) ◽  
pp. 369-373 ◽  
Author(s):  
M. T. TSENG
Keyword(s):  
Luteinizing Hormone ◽  
Rhesus Monkeys ◽  
Secretory Granules ◽  
Nuclear Chromatin ◽  
Male And Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Cytoplasmic Vesicles ◽  
Near Term ◽  
Lh Rh

SUMMARY Eighty micrograms of synthetic luteinizing hormone releasing hormone (LH-RH) were infused systemically into male and female foetuses of rhesus monkeys near term. Control animals were given infusions of saline. Morphologically, the control gonadotrophs varied from cells filled with secretory granules to highly stimulated cells with numerous cytoplasmic vesicles. In the LH-RH-treated animals, however, many cells showed depletion of secretory granules, dilatation of the endoplasmic reticulum and condensed nuclear chromatin. It is concluded, therefore, that foetal gonadotrophs can respond to administration of synthetic LH-RH.

scholarly journals Immunohistochemical Localization ofAT1a,AT1b, andAT2Angiotensin II Receptor Subtypes in the Rat Adrenal, Pituitary, and Brain with a Perspective Commentary

2013 ◽  
Vol 2013 ◽  
pp. 1-22 ◽  
Author(s):  
Courtney Premer ◽  
Courtney Lamondin ◽  
Ann Mitzey ◽  
Robert C. Speth ◽  
Mark S. Brownfield
Keyword(s):  
Angiotensin Ii ◽  
Area Postrema ◽  
Zona Glomerulosa ◽  
Immunohistochemical Localization ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Multivesicular Bodies ◽  
Sodium Appetite ◽  
Endocytic Vesicles ◽  
The Brain

Angiotensin II increases blood pressure and stimulates thirst and sodium appetite in the brain. It also stimulates secretion of aldosterone from the adrenal zona glomerulosa and epinephrine from the adrenal medulla. The rat has 3 subtypes of angiotensin II receptors:AT1a,AT1b, and AT2. mRNAs for all three subtypes occur in the adrenal and brain. To immunohistochemically differentiate these receptor subtypes, rabbits were immunized with C-terminal fragments of these subtypes to generate receptor subtype-specific antibodies. Immunofluorescence revealedAT1aand AT2receptors in adrenal zona glomerulosa and medulla.AT1bimmunofluorescence was present in the zona glomerulosa, but not the medulla. Ultrastructural immunogold labeling for theAT1areceptor in glomerulosa and medullary cells localized it to plasma membrane, endocytic vesicles, multivesicular bodies, and the nucleus.AT1band AT2, but notAT1a, immunofluorescence was observed in the anterior pituitary. Stellate cells wereAT1bpositive while ovoid cells were AT2positive. In the brain, neurons wereAT1a,AT1b, and AT2positive, but glia was onlyAT1bpositive. Highest levels ofAT1a,AT1b, and AT2receptor immunofluorescence were in the subfornical organ, median eminence, area postrema, paraventricular nucleus, and solitary tract nucleus. These studies complement those employing different techniques to characterize Ang II receptors.

INACTIVATION OF LUTEINIZING HORMONE RELEASING HORMONE BY RAT HYPOTHALAMIC L-CYSTINE ARYLAMIDASE

1975 ◽  
Vol 78 (4) ◽  
pp. 634-648 ◽  
Author(s):  
Herbert Kuhl ◽  
Hans-Dieter Taubert
Keyword(s):  
Inhibitory Effect ◽  
Supernatant Fraction ◽  
Luteinizing Hormone Releasing Hormone ◽  
Lysine Vasopressin ◽  
Hormone Effects ◽  
Rate Of Hydrolysis ◽  
Lh Rh ◽  
Hydrolysis Of ◽  
The Brain ◽  
Cystine Arylamidase

ABSTRACT The rate of hydrolysis of several aminoacyl-4-nitroanilides by rat hypothalamic arylamidases was investigated. The activity of these enzymes which were mainly found in the 105 000 × g supernatant fraction of homogenates of the hypothalamus and other parts of the brain was shown to depend upon the presence of metal ions and free thiol groups, and to be inhibited by puromycin. As previous investigations had shown that Cys-NA is an appropriate substrate for measuring hormone effects on hypothalamic arylamidases, L-cystine arylamidase and its interaction with various peptide hormones were examined in detail. It could conclusively be shown that this enzyme interacts particularly with oligopeptides. Its activity was competitively inhibited by TRF, oxytocin, lysine vasopressin, and LH-RH. It was also shown that the biological activity of LH-RH and its inhibitory effect on the hydrolysis of L-cystine-bis-p-nitroanilide decreased when it was incubated for various periods of time with the 105 000 × g supernatant of rat hypothalamus homogenate.

Effect of synthetic luteinizing hormone – releasing hormone (LH–RH) on ovulation and pituitary cytology of the goldfish Carassius auratus

1976 ◽  
Vol 54 (6) ◽  
pp. 816-824 ◽  
Author(s):  
T. J. Lam ◽  
S. Pandey ◽  
Y. Nagahama ◽  
W. S. Hoar
Keyword(s):  
Luteinizing Hormone ◽  
Secretory Granules ◽  
Ultrastructural Level ◽  
Gonadal Development ◽  
Single Type ◽  
Control Fish ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Dense Granules ◽  
Lh Rh

Synthetic luteinizing hormone – releasing hormone (LH–RH) induces ovulation and stimulates release of secretory granules from the pituitary gonadotrophs of goldfish kept at 12 ± 1 °C, a temperature at which ovulation does not occur in control fish. Gonadal development is stimulated at doses too low to induce ovulation. Relatively high doses were required to induce ovulation; this may be related to the low experimental temperatures, although several other possibilities are discussed. Intracranial injections appeared to be only slightly more effective than intraperitoneal injections. A single type of gonadotroph containing two types of granules was identified at the ultrastructural level. Only the small, electron-dense granules are released after injection of synthetic LH–RH; the role of the large, less electron-dense granules is uncertain.

scholarly journals Immunohistochemical Localization of Chromogranin A in Endocrine Tissues and Endocrine Tumors of Dogs

1998 ◽  
Vol 35 (4) ◽  
pp. 312-315 ◽  
Author(s):  
J. C. Doss ◽  
A. Grone ◽  
C. C. Capen ◽  
T. J. Rosol
Keyword(s):  
Chromogranin A ◽  
Chromaffin Cells ◽  
Endocrine Cells ◽  
Secretory Granules ◽  
Hormone Secretion ◽  
Immunohistochemical Localization ◽  
Endocrine Tumors ◽  
Parathyroid Adenomas ◽  
Immunohistochemical Identification ◽  
Endocrine Tissues

Chromogranin A is present in the secretory granules of endocrine cells and functions in hormone packaging, secretory granule stabilization, and regulation of hormone secretion. Immunohistochemical identification of chromogranin A can facilitate diagnosis of endocrine neoplasia. Normal and neoplastic canine tissues were stained immunohistochemically for chromogranin A. Staining of normal endocrine tissues demonstrated chromogranin A in chromaffin cells of the adrenal medulla, C cells of the thyroid gland, and pancreatic islets. The parathyroid chief cells and anterior pituitary stained lightly positive for chromogranin A. Pheochromocytomas (7/7), chemodectomas (5/7), islet cell carcinomas (2/6), pituitary adenomas (4/6), parathyroid adenomas (3/7), and a C-cell carcinoma (1/1) stained positive for chromogranin A. The data indicate that chromogranin A is widely distributed in canine endocrine tissues, and immunohistochemical staining of chromogranin A can be used to confirm the presence of secretory granules in endocrine tumors.

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

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