scholarly journals Expression and Roles of Pannexins in ATP Release in the Pituitary Gland

Endocrinology ◽  
2011 ◽  
Vol 152 (6) ◽  
pp. 2342-2352 ◽  
Author(s):  
Shuo Li ◽  
Ivana Bjelobaba ◽  
Zonghe Yan ◽  
Marek Kucka ◽  
Melanija Tomić ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Gap Junction ◽  
Atp Release ◽  
Intermediate Lobe ◽  
Pituitary Cells ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
Extracellular Medium ◽  
Peripheral Tissues ◽  
Pannexin 1

Pannexins are a newly discovered three-member family of proteins expressed in the brain and peripheral tissues that belong to the superfamily of gap junction proteins. However, in mammals pannexins do not form gap junctions, and their expression and function in the pituitary gland have not been studied. Here we show that the rat pituitary gland expresses mRNA and protein transcripts of pannexins 1 and 2 but not pannexin 3. Pannexin 1 was more abundantly expressed in the anterior lobe, whereas pannexin 2 was more abundantly expressed in the intermediate and posterior pituitary. Pannexin 1 was identified in corticotrophs and a fraction of somatotrophs, the S100-positive pituicytes of the posterior pituitary and AtT-20 (mouse pituitary adrenocorticotropin-secreting cells) and rat immortalized pituitary cells secreting prolactin, whereas pannexin 2 was detected in the S100-positive folliculostellate cells of the anterior pituitary, melanotrophs of the intermediate lobe, and vasopressin-containing axons and nerve endings in the posterior lobe. Overexpression of pannexins 1 and 2 in AtT-20 pituitary cells enhanced the release of ATP in the extracellular medium, which was blocked by the gap junction inhibitor carbenoxolone. Basal ATP release in At-T20 cells was also suppressed by down-regulating the expression of endogenous pannexin 1 but not pannexin 2 with their short interfering RNAs. These results indicate that pannexins may provide a pathway for delivery of ATP, which is a native agonist for numerous P2X cationic channels and G protein-coupled P2Y receptors endogenously expressed in the pituitary gland.

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.

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.

scholarly journals Plasminogen activators of the pituitary gland: enzyme characterization and hormonal modulation.

1983 ◽  
Vol 97 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
A Granelli-Piperno ◽  
E Reich
Keyword(s):  
Pituitary Gland ◽  
De Novo ◽  
Cell Monolayer ◽  
Enzyme Characterization ◽  
Anterior Lobe ◽  
Enzyme Synthesis ◽  
Intracellular Camp ◽  
Intermediate Lobe ◽  
Extracellular Medium ◽  
Hormonal Modulation

We studied plasminogen activator (PA) of the rat pituitary gland in organ and cell monolayer culture. Both anterior and intermediate lobes contain, synthesize and secrete a mixture consisting of the two known types of PA: urokinase and so-called tissue PA. Both enzymes were formed essentially by all PA secreting cells, and PA was identified specifically in mammotrophs, corticotrophs, and luteinizing hormone containing gonadotrophs. Pituitary PA production was modulated on exposure to a variety of biological effectors: anterior lobe PA secretion was stimulated by agents that raised intracellular cAMP concentration; his process depended on de novo enzyme synthesis. Enzyme production was repressed by androgens and glucocorticoids. When anterior lobe cultures were maintained in plasminogen-free media, the extracellular, secreted forms of ACTH consisted almost exclusively of the high molecular weight forms (31,000 and 23,000); the smaller forms (13,000 and 4,500) were also found in the extracellular medium of cultures supplemented with plasminogen. In contrast, the size distribution of intracellular ACTH species was unaffected by the presence of plasminogen. These results resemble those previously obtained with pancreatic islets and are consistent with the possibility that plasmin, generated by PA secretion, participates in prohormone processing. PA synthesis in intermediate lobe explants was stimulated by exposure to dibutyryl cAMP, and repressed by hydrocortisone. In accordance with the dopaminergic control of intermediate lobe function in some vertebrates, apomorphine strongly repressed PA synthesis in intermediate, but not anterior lobe cultures.

The influence of the pituitary gland on the functions and development of the organism

1927 ◽  
Vol 23 (2) ◽  
pp. 239-243
Author(s):  
A. A. Sukhov
Keyword(s):  
Pituitary Gland ◽  
Dura Mater ◽  
Animal Species ◽  
Third Ventricle ◽  
Sella Turcica ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
The Third ◽  
The Brain ◽  
Posterior Pituitary Lobe

The pituitary gland or gl. pituitaria is an organ lying at the base of the brain in a cavity formed by the sella turcica at the front, back, and bottom, and by the sinus venosus cavernosus dex. et sin. This entire cavity is lined by the dura mater, which covers it from above in the form of diaphragma sellae turcicae. Through its opening passes the infundibulum, which connects the pituitary gland in its posterior lobe with the brain. The cavity infundibuli, which is a recess of the bottom of the third ventricle, in some animal species (e.g., in dogs) passes as recessus infundibuli into the cavity of the posterior pituitary lobe (in humans this lobe has no cavity).

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.

THE MILK-EJECTING ACTIVITY OF EXTRACTS OF THE POSTERIOR PITUITARY GLAND

1952 ◽  
Vol 8 (2) ◽  
pp. 89-95 ◽  
Author(s):  
W. G. WHITTLESTONE
Keyword(s):  
Pituitary Gland ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
High Potency ◽  
Pressor Activity ◽  
Posterior Pituitary Gland ◽  
Lactating Sow

The lactating sow milked mechanically has been used for the study of the hormones of the posterior pituitary gland. The van Dyke protein and du Vigneaud's high potency posterior lobe oxytocic polypeptide have been shown to possess milk-ejecting activity equivalent to their oxytocic activity. Commercial pressor preparations and du Vigneaud's highly purified vasopressin have milk-ejecting activity corresponding to a given pressor activity which is equivalent to one-fifth of the same number of oxytocic units.

Water Intoxication and Death Associated with the Use of Posterior Pituitary Injection for Surgical Hemostasis

1986 ◽  
Vol 20 (6) ◽  
pp. 485-487 ◽  
Author(s):  
Debra H. Fiser ◽  
Gregory L. Kearns
Keyword(s):  
Pituitary Gland ◽  
Cerebral Edema ◽  
Large Volume ◽  
Therapeutic Indication ◽  
Free Water ◽  
Domestic Animals ◽  
Water Intoxication ◽  
Posterior Lobe ◽  
Posterior Pituitary

Posterior pituitary injection is an extract prepared from the dried posterior lobe of the pituitary gland from domestic animals containing two octapeptide hormones, oxytocin and vasopressin. Posterior pituitary injection carries an approved therapeutic indication as an adjunct measure for achieving surgical hemostasis. We report a case of cerebral edema and death attributed to water intoxication in a child who had received a large volume of free water concurrent with posterior pituitary injection to control bleeding after tonsillectomy and adenoidectomy.

scholarly journals CircAgtpbp1 Acts as a Molecular Sponge of miR-543-5p to Regulate the Secretion of GH in Rat Pituitary Cells

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 558
Author(s):  
ZeWen Yu ◽  
WenZhi Ren ◽  
Tian Wang ◽  
WeiDi Zhang ◽  
ChangJiang Wang ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Inhibitory Effect ◽  
Pituitary Cells ◽  
Sequencing Analysis ◽  
Hormone Regulation ◽  
Gh Secretion ◽  
Qrt Pcr ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

CircRNAs have been identified to be expressed differently and stably in numerous species and tissues, but their functions in growth hormone (GH) secretion are still largely unknown. In summary, we have revealed a circRNA-miRNA-mRNA network that may play a biological role in the rat pituitary gland. First, we verified the chromosome location information of circAgtpbp1 according to sequencing analysis. The circAgtpbp1 characteristics were authenticated through PCR, qRT–PCR, treating with RNase and fluorescent in situ hybridization (FISH). Second, we detected the expression pattern of circAgtpbp1 in the rat anterior pituitary by qRT–PCR. We also designed circAgtpbp1 siRNA and constructed overexpression plasmid to evaluate the effect of circAgtpbp1 function on GH secretion by qRT–PCR, ELISA and Western blot. CircAgtpbp1 is a stable, truly circular molecule. We found that circAgtpbp1 interacted with miR-543-5p and can regulate GH secretion in pituitary cells through a circAgtpbp1-miR-543-5p-GH axis. Overall, the evidence generated by our study suggests that circAgtpbp1 can act as a sponge of miR-543-5p to reduce the inhibitory effect of miR-543-5p on Gh1 and further promote GH secretion. These findings expand our existing knowledge on the mechanisms of hormone regulation in the pituitary gland.

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