CD9-positive cells in the intermediate lobe of the pituitary gland are important supplier for prolactin-producing cells in the anterior lobe

2021 ◽  
Author(s):  
Kotaro Horiguchi ◽  
Ken Fujiwara ◽  
Yoshito Takeda ◽  
Takashi Nakakura ◽  
Takehiro Tsukada ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Lobe ◽  
Intermediate Lobe

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.

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.

191 ESTROGEN REGULATES THE LOCALIZATION AND EXPRESSION OF CALBINDIN-D9k IN THE PITUITARY GLAND OF IMMATURE MALE RATS VIA THE ESTROGEN RECEPTOR ALPHA PATHWAY

2008 ◽  
Vol 20 (1) ◽  
pp. 175
Author(s):  
P. Tinnanooru ◽  
E.-B. Jeung
Keyword(s):  
Estrogen Receptor ◽  
Pituitary Gland ◽  
Estrogen Receptor Alpha ◽  
Anterior Lobe ◽  
Male Rats ◽  
Specific Cell ◽  
Intermediate Lobe ◽  
Immature Male ◽  
Calbindin D9k ◽  
Selective Ligand

Estrogen (E2; estradiol) plays a key role in the regulation of many pituitary hormones. It exerts its effects by binding to the intracellular estrogen receptor (ER), which then functions as a transcription factor. Although E2 has been shown to regulate calbindin-D9k (CaBP-9k) in the female reproductive system of rodents, the effects of E2 on the regulation of CaBP-9k in male rats remains to be elucidated. For investigation of E2-induced regulation of the pituitary CaBP-9k gene, immature male rats were injected with E2 daily for three consecutive days with a dose of 40 µg kg–1 body weight (BW). The expression levels of CaBP-9k mRNA and protein were analyzed by RT-PCR and Western blot analysis, respectively, in the absence and presence of ICI 182 780 (ICI), an E2 antagonist. In addition, the tissue localization of CaBP-9k was determined by immunohistochemistry. CaBP-9k was localized in the cytoplasm of a specific cell type (acidophils) in the anterior lobe of the pituitary gland and highly expressed in the intermediate lobe. Exposure to E2 increased the number of cells that stained positive for CaBP-9k. For determination of which ER subtype is involved in CaBP-9k regulation in the pituitary, the immature rats were treated with 1 mg kg–1 BW propyl pyrazole triol (PPT, an ER-α-selective ligand) or diarylpropionitrile (DPN, an ER-β-selective ligand) for three days. The data were analyzed by the non-parametric procedure of the Kruskal-Wallis test, followed by Dunnett's test for two-pair comparisons. Pituitary CaBP-9k expression was mainly mediated by PPT in immature male rats, whereas no significant alteration of pituitary CaBP-9k gene expression was observed after DPN treatment. In addition, the estrogenicity of PPT in the induction of CaBP-9k expression was completely blocked by an estrogen antagonist, ICI 182 780, indicating that pituitary CaBP-9k expression is solely induced by ER-α. Taken together, these results suggest that pituitary CaBP-9k is induced by estrogen in male rats and its expression is predominantly regulated by ER-α, but not ER-β.

Demonstration of desacetyl α-melanocyte-stimulating hormone in fetal and adult human anterior pituitary corticotrophs

1989 ◽  
Vol 120 (3) ◽  
pp. 525-NP ◽  
Author(s):  
P. J. Coates ◽  
I. Doniach ◽  
J. M. P. Holly ◽  
L. H. Rees
Keyword(s):  
Pituitary Gland ◽  
High Performance ◽  
Anterior Lobe ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Melanocyte Stimulating Hormone ◽  
Pars Anterior ◽  
Human Anterior Pituitary

ABSTRACT Immunocytochemistry, radioimmunoassay and high-performance liquid chromatography (HPLC) techniques have been used in combination to investigate the presence of immunoreactive (ir)-α-MSH in the normal human pituitary gland, and to investigate the possible origin of these cells from the fetal pars intermedia. Two separate antisera to α-MSH were employed in immunocytochemistry to distinguish between authentic α-MSH and the desacetyl form. Only desacetyl α-MSH was detected in the pituitary gland of fetal and adult man, in both the pars (zona) intermedia and the pars anterior. In the fetus, a large proportion of the ACTH-containing cells of the anterior lobe also contained ir-α-MSH, while ir-α-MSH containing cells were more sparse in adults. Radioimmunoassay of acid extracts of adult pituitary tissue showed α-MSH levels representing less than 0·05% of the ACTH content of the gland. HPLC analysis of these extracts confirmed that only the desacetyl form was present. These results suggest that α-MSH peptides are synthesized by anterior lobe cells of the human pituitary gland, which are not derived from the fetal pars intermedia. Possible regulatory mechanisms affecting cells which contain ir-α-MSH are discussed, and by comparison with the intermediate lobe of other species it is concluded that there is little evidence for a true intermediate lobe in the human pituitary gland. Journal of Endocrinology (1989) 120, 525–530

A COMPARISON BETWEEN THE EXOPHTHALMOS INHIBITING EFFECTS OF SODIUM-D- AND SODIUM-L-THYROXINE IN GUINEA PIGS

1962 ◽  
Vol 41 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Björn Tengroth ◽  
Uno Zackrisson
Keyword(s):  
Hyaluronic Acid ◽  
Pituitary Gland ◽  
Guinea Pigs ◽  
Anterior Lobe ◽  
Optical Isomers ◽  
Connective Tissues ◽  
Response Curves ◽  
Experimental Animals ◽  
Inhibiting Effect ◽  
Caloric Effect

ABSTRACT The general change in the connective tissues which occurs in animals with experimentally produced exophthalmos, consists in an increase in the amount of hyaluronic acid, which binds the water in the connective tissue. Many regard this process as a stimulation of the mucinous system in the connective tissues, and consider this an explanation of the phenomenon of exophthalmos. When the experimental animals are injected with thyroxine or thyroid extract, the reaction observed is opposite to that seen following the injection of the anterior lobe of the pituitary gland. In the former case, there is a reduction in the amount of hyaluronic acid and consequently a decrease in the water content in the connective tissues. In the experiments in question, Na-d-thyroxine and Na-l-thyroxine), in crystalline form, were tested for their inhibiting effect on the development of exophthalmos in experimental animals. The animals used were male albino guinea-pigs. An extract of the anterior lobe of the pituitary gland (TSH Organon)) was used to produce exophthalmos. In previous work (Tengroth 1961), it was shown, using an X-ray measuring technique, that d-thyroxine, despite its poor caloric effect, like l-thyroxine had an exophthalmos-inhibiting effect. When comparing the dose-response curves of the exophthalmos-inhibiting properties of both these optical isomers, it appears that d-thyroxine has an inhibiting effect which is significantly greater than that of l-thyroxine. The significance of this observation is discussed.

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
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