scholarly journals Immunocytochemical demonstration of tissue-type plasminogen activator in endocrine cells of the rat pituitary gland.

1985 ◽  
Vol 101 (1) ◽  
pp. 305-311 ◽  
Author(s):  
P Kristensen ◽  
L S Nielsen ◽  
J Grøndahl-Hansen ◽  
P B Andresen ◽  
L I Larsson ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Endocrine Cells ◽  
Large Population ◽  
Cell Types ◽  
Anterior Lobe ◽  
Tissue Type ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Rat Pituitary

We immunocytochemically stained rat pituitary glands using antibodies against plasminogen activators of the tissue type (t-PA) and the urokinase type (u-PA). A large population of endocrine cells in the anterior lobe of the gland displayed intense cytoplasmic immunoreactivity with anti-t-PA. In some areas of the intermediate lobe we found a weak staining, and we observed weakly staining granular structures in the posterior lobe. Controls included absorption of the antibodies with highly purified t-PA. In addition, SDS PAGE followed by immunoblotting of pituitary gland extracts revealed only one band with an electrophoretic mobility similar to that of t-PA when stained with anti-t-PA IgG. No u-PA immunoreactivity was detected in the rat pituitary gland. Sequential staining experiments using antibodies against growth hormone and t-PA demonstrated that the t-PA-immunoreactive cells constitute a large subpopulation of the growth hormone-containing cells. These findings represent the first direct evidence for the presence of t-PA in cell types other than endothelial cells in the intact normal organism. In this article we discuss the implications of the results for a possible role of t-PA in the posttranslational processing of prohormones.

Effects of TRH, prolactin and TSH on cell proliferation in the intermediate lobe of the rat pituitary gland

1996 ◽  
Vol 148 (2) ◽  
pp. 193-196 ◽  
Author(s):  
T Pawełczyk ◽  
M Pawlikowski ◽  
J Kunert-Radek
Keyword(s):  
Cell Proliferation ◽  
Body Weight ◽  
Pituitary Gland ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
Proliferating Cells ◽  
Rat Pituitary ◽  
Trh Analogues ◽  
Intermediate Pituitary Lobe ◽  
Significant Stimulatory Effect

Abstract The effect of TRH on cell proliferation in the anterior lobe of the pituitary is well known and documented. On the other hand, there are no data on the effects of TRH on the intermediate lobe of the pituitary gland. The aim of this study was to investigate the effect of TRH and its analogues (pGlu-His-Gly, pGlu-His-Gly-NH2) on cell proliferation in the intermediate pituitary lobe. The bromodeoxyuridine technique was used to detect the proliferating cells. It was found that TRH stimulated cell proliferation 24 h after a single injection at a dose of 100 μg/kg body weight. The TRH analogues did not exert any significant stimulatory effect either 12 h or 24 h after the injection. The second experiment was carried out to distinguish the probable mechanism of the action of TRH. The effects of TSH and prolactin (PRL) on intermediate lobe cell proliferation were examined. It was found that both PRL and TSH exerted a significant stimulatory effect 24 h after a single s.c. injection of PRL at a dose of 150 IU/kg body weight or TSH at a dose 20 IU/kg body weight. It therefore appears that the stimulatory effect of TRH on intermediate pituitary lobe cell proliferation is mediated by PRL and TSH. Journal of Endocrinology (1996) 148, 193–196

scholarly journals Hes1 and Hes5 Control the Progenitor Pool, Intermediate Lobe Specification, and Posterior Lobe Formation in the Pituitary Development

2007 ◽  
Vol 21 (6) ◽  
pp. 1458-1466 ◽  
Author(s):  
Aya Kita ◽  
Itaru Imayoshi ◽  
Masato Hojo ◽  
Masashi Kitagawa ◽  
Hiroshi Kokubu ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Progenitor Cells ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Endocrine Organ ◽  
Pituitary Development ◽  
Proliferation And Differentiation ◽  
Pituitary Hypoplasia ◽  
Multiple Signaling

Abstract The pituitary gland is composed of two distinct entities: the adenohypophysis, including the anterior and intermediate lobes, and the neurohypophysis, known as the posterior lobe. This critical endocrine organ is essential for homeostasis, metabolism, reproduction, and growth. The pituitary development requires the control of proliferation and differentiation of progenitor cells. Although multiple signaling molecules and transcription factors are required for the proper pituitary development, the mechanisms that regulate the fate of progenitor cells remain to be elucidated. Hes genes, known as Notch effectors, play a crucial role in specifying cellular fates during the development of various tissues and organs. Here, we report that mice deficient for Hes1 and Hes5 display severe pituitary hypoplasia caused by accelerated differentiation of progenitor cells. In addition, this hypoplastic pituitary gland (adenohypophysis) lacks the intermediate lobe and exhibits the features of the anterior lobe only. Hes1 and Hes5 double-mutant mice also lack the neurohypophysis (the posterior lobe), probably due to incomplete evagination of the diencephalon. Thus, Hes genes control not only maintenance of progenitor cells but also intermediate vs. anterior lobe specification during the adenohypophysis development. Hes genes are also essential for the formation of the neurohypophysis.

scholarly journals Immunocytochemical Localization of Secretogranin III in the Anterior Lobe of Male Rat Pituitary Glands

2003 ◽  
Vol 51 (2) ◽  
pp. 227-238 ◽  
Author(s):  
Yuko Sakai ◽  
Masahiro Hosaka ◽  
Yoshiki Hira ◽  
Tatsuo Harumi ◽  
Yoshiyuki Ohsawa ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Secretory Granule ◽  
Endocrine Cells ◽  
Secretory Granules ◽  
Anterior Lobe ◽  
Male Rat ◽  
Secretory Proteins ◽  
Chromogranin B ◽  
Rat Pituitary ◽  
Granule Membrane

Secretogranin III (SgIII) is one of the acidic secretory proteins, designated as granins, which are specifically expressed in neuronal and endocrine cells. To clarify its precise distribution in the anterior lobe of the rat pituitary gland, we raised a polyclonal antiserum against rat SgIII for immunocytochemical analyses. By immunohistochemistry using semithin sections, positive signals for SgIII were detected intensely in mammotropes and thyrotropes, moderately in gonadotropes and corticotropes, but not in somatotropes. The distribution pattern of SgIII in the pituitary gland was similar to that of chromogranin B (CgB), also of the granin protein family, suggesting that the expressions of these two granins are regulated by common mechanisms. The localization of SgIII in endocrine cells was confirmed by immunoelectron microscopy. In particular, secretory granules of mammotropes and thyrotropes were densely and preferentially co-labeled for SgIII and CgB in their periphery. Moreover, positive signals for SgIII were occasionally found in cells containing both prolactin and TSH in secretory granules. These lines of evidence suggest that SgIII and CgB are closely associated with the secretory granule membrane and that this membrane association might contribute to gathering and anchoring of other soluble constituents to the secretory granule membrane.

scholarly journals Estrogen Receptors are Involved in Xenoestrogen Induction of Growth Hormone in the Rat Pituitary Gland

2009 ◽  
Vol 55 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Vu Hoang DANG ◽  
Kyung-Chul CHOI ◽  
Eui-Bae JEUNG
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Estrogen Receptors ◽  
Rat Pituitary

Desensitization of the D-2 dopamine receptor and the β2-adrenoceptor in the intermediate lobe of the rat pituitary gland

1983 ◽  
Vol 5 (6) ◽  
pp. 803-810 ◽  
Author(s):  
K. Miyazaki ◽  
J.M. Saavedra ◽  
T.E. Cote ◽  
J.W. Kebabian
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Rat Pituitary

On the content of prolan in the pituitary gland

1934 ◽  
Vol 30 (6) ◽  
pp. 634-634
Author(s):  
P. Badul
Keyword(s):  
Pituitary Gland ◽  
Histological Examination ◽  
Anterior Lobe ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
Posterior Pituitary Lobe

The posterior lobe of the pituitary gland in a bull is free of prolan, while in a human it contains prolan. Only here it can be found in that part of the posterior pituitary lobe adjacent to the anterior lobe. In the bull, too, this part of the pituitary gland is completely free of prolan content. Histological examination shows that in humans, this part of the posterior lobe is crossed by bands of cells from the anterior lobe, which consist exclusively of basophilic cells.

The D-2 Dopamine Receptor in the Intermediate Lobe of the Rat Pituitary Gland

1983 ◽  
pp. 33-72 ◽  
Author(s):  
J. W. KEBABIAN ◽  
M. BEAULIEU ◽  
T. E. COTE ◽  
R. L. ESKAY ◽  
E. A. FREY ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Rat Pituitary

On the Pituitary of the Perch (Peroa Fluviatilis)

1942 ◽  
Vol s2-83 (331) ◽  
pp. 299-316
Author(s):  
T. KERR
Keyword(s):  
Connective Tissue ◽  
Blood Vessels ◽  
Perca Fluviatilis ◽  
Cell Types ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
General Description ◽  
Perch Perca Fluviatilis ◽  
Higher Types ◽  
Different Cell Types

1. A general description is given of the pituitary of the perch (Perca fluviatilis L.), and histological details of its various parts. The subdivisions of the glandular component are confluent with each other but distinguished by their different cell types. The nervous lobe makes contact with all three of the subdivisions, but is separated from them by a layer of connective tissue, incomplete in particular areas. 2. The anterior glandular region (anterior lobe) has an anterior chromophil and a posterior chromophobe zone. The middle glandular region (transitional lobe) possesses brightly staining acidophils and basophils as well as chromophobes. The acidophils form a dorsal sheet, deeply indented by processes of the nervous lobe, the basophils lie ventrally and posteriorly, and chromophobes are common towards the extremities of the indentations. The posterior glandular region (intermediate lobe) is elaborately penetrated by nervous lobe processes; the cells are small and consist of amphiphils, dull basophils, and occasional dull acidophils. The possible homologies of these regions to the lobes of higher types are discussed. The nervous lobe is of loose glial tissue with many nuclei and blood vessels and some reticular and collagenous fibres. 3. Strongly acidophil spheres of various sizes and in various numbers occur in the middle glandular region. They originate in ‘sphere cells’ resembling eosinophil leucocytes and after enlarging become free in the tissues of the region. Later they appear to pass into the posterior processes of the nervous lobe to be the larger bodies of the Herring material. Finally these larger elements appear to break down to form a fine granulation, whose further fate could not be followed.

Vasopressin-binding sites in the pig pituitary gland: competition by novel vasopressin antagonists suggests the existence of an unusual receptor subtype in the anterior lobe

1994 ◽  
Vol 141 (3) ◽  
pp. 383-391 ◽  
Author(s):  
Y Arsenijevic ◽  
M Dubois-Dauphin ◽  
E Tribollet ◽  
M Manning ◽  
W H Sawyer ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Rat Liver ◽  
Arginine Vasopressin ◽  
Binding Sites ◽  
Anterior Lobe ◽  
Receptor Subtype ◽  
Lower Affinity ◽  
Corticotrophin Releasing Factor ◽  
Rat Pituitary ◽  
Acth Release

Abstract Arginine vasopressin (AVP) acts in the pituitary gland, in synergy with corticotrophin-releasing factor, to induce ACTH release in response to stressful stimuli. Pituitary AVP receptors in the rat are coupled to phospholipase C, as are the so-called V1-type AVP receptors. The present study examined [3H]AVP binding in membranes prepared from the anterior lobe of the pituitary gland of the pig. [3H]AVP, alone or in competition with analogues, bound to sites in the pig anterior lobe which are pharmacologically similar to those described previously by others in the rat pituitary gland. For comparison, the same competition studies were performed on membrane preparations from the rat liver which contain the classic V1-type AVP receptor. Pituitary and liver AVP-binding sites were dissimilar; both cyclic and linear V1 antagonists had, in general, a much lower affinity for pituitary AVP-binding sites than for those in the liver. Thus, Phaa-d-Tyr(Et)-Phe-Gln-Asn-Lys-Pro-Arg-NH2 (Phaa=phenylacetyl) has a 2500-fold greater affinity for the latter (negative logarithm of inhibition constant (pKi)=9·64) than for the former (pKi=6·22). One linear antagonist, Pa-d-Tyr-Phe-Val-Asn-Arg-Pro-Arg-Arg-NH2 (Pa=propionyl) had about equal affinities for liver and pituitary membranes (pKi=6·39 and 6·53 respectively). Another compound, Phaa-d-Tyr-Phe-Val-Asn-Arg-Pro-Arg-Arg-NH2 had the highest affinity found to date for binding to AVP sites in the pituitary (pKi=7·43). These findings suggest some ideas for the design of more potent and/or selective AVP analogues acting in the pituitary gland. Journal of Endocrinology (1994) 141, 383–391

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