scholarly journals Production of transferrin-like immunoreactivity by rat anterior pituitary and intermediate lobe.

1995 ◽  
Vol 43 (7) ◽  
pp. 657-664 ◽  
Author(s):  
D Tilemans ◽  
V V Vijver ◽  
G Verhoeven ◽  
C Denef
Keyword(s):  
Cell Cultures ◽  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Intermediate Lobe ◽  
Pituitary Cells ◽  
Metabolic Labeling ◽  
Double Immunostaining ◽  
Sds Page ◽  
Topographical Distribution ◽  
S 100

Using a specific anti-rat transferrin (Tf) antiserum, Tf-like immunoreactivity (Tf-lir) was detected by immunostaining in intact rat pituitaries and in reaggregated pituitary cells cultured in serum-free medium. Tf-lir cells were present in the anterior pituitary (AP), and in the intermediate (IL) and neural lobes (NL). In the AP, Tf-lir cells were oval or polygonal. An unusual topographical distribution was found. Tf-lir cells mainly occurred as dense clusters in the lateral wings. In the central part of the AP, Tf-lir was found in flattened perisinusoidal cells. Double immunostaining for Tf and the different pituitary hormones showed that Tf-lir co-localized with some gonadotrophs and somatotrophs (7% and 3% of Tf-lir cells, respectively, in typical sections). No co-localization was seen with PRL, ACTH, TSH, or alpha-MSH. The distribution of Tf-lir cells and their cell shape completely differed from that of S-100-positive cells in the AP. In the IL, clusters of large stellate Tf-lir cells were found. Again, their distribution completely differed from S-100-positive cells. In the NL, diffuse staining was found. Double immunostaining of paraffin-embedded sections of reaggregate cell cultures of the AP did not reveal any co-localization of Tf-lir with ACTH, alpha-MSH, LH, FSH, TSH, GH, or PRL. In aggregates consisting of NL + IL cells, Tf-lir was located in clusters: no co-localization with ACTH or alpha-MSH could be demonstrated. Reaggregate cell cultures of AP and NL + IL secreted Tf-lir as measured by radioimmunoassay, at least during 21 days of culture. After metabolic labeling with [35S]-methionine and immunoprecipitation of [35S]-methionine-labeled material present in the culture medium of both AP and NL + IL aggregates with anti-Tf antiserum, a 35S-labeled substance was found, which on SDS-PAGE showed an apparent M(r) of approximately 78 KD, corresponding to the M(r) of rat Tf. The present data show that a specific population of cells of rat anterior pituitary is capable of synthesizing, storing, and secreting transferrin or a substance closely related to it. Cells different from melanotrophs and S-100 cells in the IL, as well as pituicytes in the NL, also appear to produce this material. We suggest that transferrin or a transferrin-like substance may have a local role in the transport of iron or other metals or may play a role as growth factor in the three lobes of the pituitary gland.

Pituitary Disorders

2016 ◽  
pp. 191-202
Author(s):  
Pankaj Shah
Keyword(s):  
Metastatic Disease ◽  
Anterior Pituitary ◽  
Pituitary Tumors ◽  
Pituitary Hormones ◽  
Pituitary Cells ◽  
Pituitary Disease ◽  
Tissue Resistance ◽  
Common Causes ◽  
Sheehan Syndrome ◽  
Pituitary Infarction

Hypopituitarism usually results from a deficiency of anterior pituitary hormones or, rarely, from tissue resistance to these hormones. Deficiency may be from primary pituitary disease, pituitary stalk disorders, hypothalamic disease, or an extrasellar disorder impinging on, or infiltrating, the hypothalamic-pituitary unit. Primary pituitary disease results from the loss of anterior pituitary cells and may be congenital or acquired. Common causes are pituitary tumors and their surgical or radiotherapeutic ablation. Infrequent causes include pituitary infarction (eg, postpartum pituitary necrosis, also known as Sheehan syndrome), pituitary apoplexy, lymphocytic hypophysitis, infiltrative diseases (eg, hemochromatosis), and metastatic disease (eg, from breast or lung).

Mastoparan, a wasp venom peptide, stimulates release of prolactin from cultured rat anterior pituitary cells

1994 ◽  
Vol 142 (1) ◽  
pp. 9-18 ◽  
Author(s):  
S E Mau ◽  
M R Witt ◽  
H Vilhardt
Keyword(s):  
Protein Kinase ◽  
Cell Cultures ◽  
Anterior Pituitary ◽  
Inositol Phosphates ◽  
Pituitary Cell ◽  
Secretory Process ◽  
Protein Kinase Activity ◽  
Pituitary Cells ◽  
Anterior Pituitary Cells ◽  
Intracellular Ca

Abstract Studies have shown that mastoparan and other amphiphilic peptides induce exocytosis of hormones from anterior pituitary cells. We have studied the effect of mastoparan on the secretion of prolactin from cultured rat anterior pituitary cells and on the concomitant functional status of signal-transducing pathways in lactotroph-enriched cell cultures. Mastoparan stimulation of prolactin secretion was dose-dependent, time-dependent, reversible and required the presence of calcium. Pretreatment of pituitary cell cultures with cholera and pertussis toxin had no effect on the secretory response, whereas encapsulation of guanosine 5-[β-thio]diphosphate (GDP-β-S) by reversible electropermeabilization inhibited mastoparan-stimulated secretion. Incubation of mastoparan with myo[3H]inositol-labelled lactotroph-enriched anterior pituitary cell cultures resulted in increased formation of inositol phosphates compared with control cells, and encapsulation of GDP-β-S blocked mastoparan-induced inositol lipid hydrolysis. Mastoparan caused translocation of protein kinase C activity from a soluble to a membrane-attached form. Mastoparan was able to increase the intracellular Ca2+ concentration in Fura-2-loaded individual lactotrophs. Omission of Ca2+ from the extracellular medium did not change the Ca2+ response in lactotrophs when stimulated with mastoparan. On the basis of these results it is concluded that mastoparan-induced release of prolactin is preceded by activation of the inositol(1,4,5)trisphosphate/diacylglycerol pathway with resulting translocation of protein kinase activity and increment in intracellular Ca2+. However, other signal-transducing pathways may be involved in the secretory process. Journal of Endocrinology (1994) 142, 9–18

Immunocytochemical evidence that S-100-positive cells of the mouse anterior pituitary contain interleukin-6 immunoreactivity.

1993 ◽  
Vol 41 (2) ◽  
pp. 151-156 ◽  
Author(s):  
H Vankelecom ◽  
P Matthys ◽  
J Van Damme ◽  
H Heremans ◽  
A Billiau ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Anterior Pituitary ◽  
Tumor Cell Line ◽  
Polyclonal Antiserum ◽  
Positive Staining ◽  
Pituitary Cells ◽  
S 100 ◽  
Mouse Pituitary ◽  
Acth Secreting

We have previously shown that bioactive interleukin-6 (IL-6) is produced by rat and mouse (anterior) pituitary cells in vitro. Since the amount produced correlated with the presence of S-100-containing folliculostellate (FS) cells, these cells were suggested to be a source of IL-6 in the anterior pituitary (AP) lobe. In the present study we used immunocytochemical techniques to confirm this presumption. Freshly isolated mouse pituitary cells were subjected to immunocytochemical procedures whereby two different (neutralizing) monoclonal antibodies (MAb) against mouse IL-6 (6B4 and 20F3) and a polyclonal antiserum raised against bovine S-100 were used as primary antibodies. Single immunostaining revealed a small portion of mouse pituitary cells (about 6.5%) to be positive for IL-6 immunoreactivity with both antibodies. Importantly, the same proportion of cells was found to be IL-6 positive if only the AP was used as the cell source. About 7.5% of the pituitary cells stained for the presence of S-100 immunoreactivity. Positive staining for IL-6 was also found in pituitary cell samples from 2-day-old monolayer cultures and from redispersed 9-day-old histotypic aggregates, which both secreted bioassayable IL-6. In contrast, no IL-6 staining was found in AtT-20 cells, an established ACTH-secreting tumor cell line of the mouse pituitary which did not secrete bioactive IL-6. The specificity of the IL-6 immunostaining was demonstrated by a total loss of staining when MAb 6B4 was omitted or replaced by irrelevant rat IgG. Conclusively, pre-adsorption of the anti-IL-6 MAb (6B4) with recombinant mouse IL-6 totally abolished staining of pituitary cells. Double immunostaining for IL-6 and S-100 revealed that most if not all of the IL-6-containing pituitary cells were positive for S-100. Few of the S-100-containing cells did not stain for IL-6. These results confirm our previous hypothesis that FS cells, characterized by immunostaining of S-100 protein, contain bioactive and immunoreactive IL-6 and therefore are very likely producers of IL-6 in the AP. Furthermore, our results suggest that IL-6 is implicated in the local regulatory role ascribed to FS cells in the pituitary gland.

scholarly journals Novel fish hypothalamic neuropeptides stimulate the release of gonadotrophins and growth hormone from the pituitary of sockeye salmon

2006 ◽  
Vol 188 (3) ◽  
pp. 417-423 ◽  
Author(s):  
Masafumi Amano ◽  
Shunsuke Moriyama ◽  
Masayuki Iigo ◽  
Shoji Kitamura ◽  
Noriko Amiya ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Sockeye Salmon ◽  
Brain Regions ◽  
Pituitary Hormones ◽  
Reversed Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Pituitary Cells ◽  
Reversed Phase Hplc ◽  
Hypothalamic Neuropeptides ◽  
The Brain

We recently identified a cDNA encoding three novel fish hypothalamic neuropeptides, having LPXRF-NH2 from the goldfish brain. In this study, to clarify the physiological functions of these three LPXRFamide peptides (gfLPXRFa-1, -2, and -3), we analysed the localisation and hypophysiotrophic activity of these peptides using sockeye salmon, Oncorhynchus nerka, in which immunoassay systems for several anterior pituitary hormones have been developed. gfLPXRFa-immunoreactive cell bodies were detected in the nucleus posterioris periventricularis of the hypothalamus and immunoreactive fibres were distributed in various brain regions and the pituitary. We also detected gfLPXRFa-immunoreactivity in the pituitary by competitive enzyme-linked immunosorbent assay combined with reversed-phase HPLC. These three gfLPXRFamide peptides stimulated the release of FSH, LH and GH, but did not affect the release of prolactin (PRL) and somatolactin (SL) from cultured pituitary cells. These results suggest that novel fish hypothalamic LPXR-Famide peptides exist in the brain and pituitary of sockeye salmon and stimulate the release of gonadotrophins and GH from the pituitary.

The expression of regulated endocrine-specific protein of 18 kDa in peptidergic cells of rat peripheral endocrine tissues and in blood

1997 ◽  
Vol 155 (2) ◽  
pp. 329-341 ◽  
Author(s):  
DN Darlington ◽  
MR Schiller ◽  
RE Mains ◽  
BA Eipper
Keyword(s):  
Molecular Weight ◽  
Pancreatic Islets ◽  
Adrenal Medulla ◽  
Anterior Pituitary ◽  
Cellular Localization ◽  
Secretory Granules ◽  
Specific Protein ◽  
Intermediate Lobe ◽  
Pituitary Cells ◽  
Endocrine Tissues

We examined the cellular localization of regulated endocrine-specific protein of 18 kDa (RESP18) and mRNA in peripheral endocrine tissues. In situ hybridization and immunocytochemistry identified RESP18 mRNA in most cells of the anterior and intermediate pituitary, with RESP18 protein apparent in many anterior pituitary cells but very few intermediate pituitary cells. In the adrenal medulla and superior cervical ganglion, RESP18 mRNA co-localized with dopamine beta-mono-oxygenase and neuropeptide Y. In the thyroid, RESP18 mRNA was localized to C-cells. RESP18 mRNA was expressed in most of the cells of the pancreatic islets, co-localizing with insulin, glucagon, and somatostatin. No RESP18 mRNA or protein was detected in the adrenal cortex, ovary, neural lobe of the pituitary, parathyroid, exocrine pancreas, thyroid follicular cells, placenta, mammary tissue, liver, lung, or atria. As in the intermediate lobe of the pituitary, high levels of RESP18 mRNA in the pancreatic islets and adrenal medulla did not always correlate with immunodetectable RESP protein, suggesting that post-transcriptional mechanisms are important in controlling RESP18 expression. Western blot analyses identified 18 kDa RESP and higher molecular weight isoforms of RESP in most tissues and in plasma. Subcellular fractionation of the anterior pituitary identified 18 kDa RESP18 in fractions enriched in endoplasmic reticulum and secretory granules, with the higher molecular weight isoforms of RESP18 concentrated in fractions enriched in secretory granules. The broad neuroendocrine distribution of RESP18 suggests that it subserves an important function in the secretory pathway that is common to the production of many secreted peptides.

scholarly journals Rat Anterior Pituitary Folliculostellate Cells Are Targets of Interleukin-1β and a Major Source of Intrapituitary Follistatin

Endocrinology ◽  
2003 ◽  
Vol 144 (2) ◽  
pp. 732-740 ◽  
Author(s):  
Louise M. Bilezikjian ◽  
Angela M. O. Leal ◽  
Amy L. Blount ◽  
Anne Z. Corrigan ◽  
Andrew V. Turnbull ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Cell Function ◽  
Pituitary Hormones ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Mrna Accumulation ◽  
Folliculostellate Cells ◽  
Pituitary Adenylate Cyclase ◽  
Immortalized Cell ◽  
Insight Into

Folliculostellate cells of the anterior pituitary are postulated to be an important source of factors, such as follistatin, that regulate pituitary function by intercellular communication. To gain further insight into the function of this cell type, folliculostellate cells were enriched from cultured rat anterior pituitary cells, and an immortalized cell line designated FS/D1h was established and characterized. These FS/D1h cells express S100 immunoreactivity and produce IL-6 but not pituitary hormones such as GH, ACTH, FSH, and LH. Importantly, FS/D1h cells express large amounts of follistatin mRNA and secrete the protein, as quantified indirectly by the amount of [125I]activin A immunoprecipitated with a follistatin antiserum. The FS/D1h cells also express α, βA, and βB inhibin/activin subunit mRNAs, but whether they produce the corresponding activins and inhibins has not been determined. The response of FS/D1h cells to agents thought to modulate folliculostellate cell function was evaluated. IL-1β (0.005–5 nm) stimulated the secretion of follistatin and increased mRNA expression. In parallel, IL-6 secretion was stimulated. Dexamethasone, pituitary adenylate cyclase-activating polypeptide(1–27), and lipopolysaccharide but not testosterone, 12-O-tetradecanoylphorbol-13-acetate, or forskolin also increased follistatin secretion. Surprisingly, activin had no effect on follistatin mRNA levels, despite the fact that FS/D1h cells express ActRII, ActRIIB, and ALK-4 (ActRIB). Activin, on the other hand, induced Smad7 mRNA accumulation and exerted an antiproliferative effect on FS/D1h cells. Altogether, these observations support the possibility that follistatin originating from folliculostellate cells participates in mediating the effects of IL-1β, glucocorticoids, and other agents on the response of pituitary cells to activins.

scholarly journals Inducible Nitric Oxide Synthase in the Anterior Pituitary Gland: Induction by Interferon-γ in a Subpopulation of Folliculostellate Cells and in an Unidentifiable Population of Non-hormone-secreting Cells

1997 ◽  
Vol 45 (6) ◽  
pp. 847-857 ◽  
Author(s):  
Hugo Vankelecom ◽  
Patrick Matthys ◽  
Carl Denef
Keyword(s):  
Nitric Oxide ◽  
Cell Cultures ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Endocrine System ◽  
Interferon Γ ◽  
S 100 ◽  
Ifn Γ ◽  
Oxide Synthase

In the context of immune-endocrine relationships, we have previously shown that interferon-γ (IFN-γ) inhibits hormone secretion in anterior pituitary (AP) cell cultures. The non-hormone-secreting folliculostellate (FS) cells were found to mediate this inhibitory action. Because in the immune system IFN-γ is a strong stimulator of nitric oxide (NO) release through the induction of NO synthase (NOS), we investigated whether the inducible form of NOS (iNOS) is present in (rat) AP cell cultures, and whether its expression is stimulated by IFN-γ. Immunocytochemistry revealed that under basal in vitro conditions only a very few AP cells contained iNOS. Treatment with IFN-γ caused a sixfold rise in the number of iNOS-positive cells and augmented the intensity of the staining. The increased number of iNOS-expressing cells was paralleled by elevated production of NO. Some of the iNOS-positive cells extended cytoplasmic processes between hormone-secreting cells, which is a characteristic of FS cells. Immunostaining of FS cell-poor and FS cell-enriched populations (obtained by gradient sedimentation) also suggested the presence of iNOS in a subpopulation of FS cells. By double immunofluorescence techniques we found that about 65% of iNOS-expressing cells were positive for S-100, a marker protein for FS cells. However, around 80% of the S-100-positive cells were not labeled for iNOS. On the other hand, the majority of the S-100-negative iNOS-containing cells could not be further identified by antisera against the classical AP hormones, suggesting the presence of iNOS in a still unidentified non-hormone-secreting cell type of the AP gland. This report is the first to demonstrate the expression of the inducible form of NOS in the AP gland. IFN-γ upregulates this expression, showing that cytokines may use the same signaling mechanisms in both the immune and the endocrine system. In addition, a putative new function of a subpopulation of FS cells in the paracrine regulation of the AP gland is suggested.

Adrenal regeneration in the rat is mediated by mitogenic N-terminal pro-opiomelanocortin peptides generated by changes in precursor processing in the anterior pituitary

1988 ◽  
Vol 116 (2) ◽  
pp. 207-216 ◽  
Author(s):  
F. E. Estivariz ◽  
M. I. Morano ◽  
M. Carino ◽  
S. Jackson ◽  
P. J. Lowry
Keyword(s):  
Mitotic Activity ◽  
Plasma Levels ◽  
Anterior Pituitary ◽  
Anterior Lobe ◽  
Rabbit Serum ◽  
Sham Operation ◽  
Intermediate Lobe ◽  
Normal Rabbit Serum ◽  
Pituitary Cells ◽  
Adrenalectomized Rats

ABSTRACT In order to investigate the role of N-terminal proopiomelanocortin (N-POMC) in adrenal regeneration after bilateral adrenal enucleation (hereafter referred to as enucleation) rats 13 days after enucleation were injected (200 μl s.c. plus 200 μl i.p.) at 08.00 and 20.00 h with normal rabbit serum (NRS), an ACTH antiserum or an N-POMC antiserum. On the next day the animals were injected with colchicine, killed and mitotic figures in adrenal histological sections counted. The same treatment was given to rats 20 days after enucleation. Only the N-POMC antiserum significantly diminished adrenal mitotic activity 14 and 21 days after enucleation (P < 0·01 and 0·05 respectively) when compared with NRS-treated enucleated rats, whereas plasma corticosterone levels in rats 14 days after enucleation were significantly (P < 0·005) decreased only by treatment with ACTH antiserum. To determine whether the mitogenic N-POMC peptides involved in adrenal regeneration originated from the pituitary intermediate lobe, 0·9% (w/v) NaCl or ergocryptine (10 mg/kg body weight) was administered s.c. twice daily to rats between 7 and 13 days after enucleation. On day 14, adrenal mitotic activity and plasma levels of ACTH and N-POMC were not significantly different between ergocryptine and saline-treated enucleated rats, whereas α-MSH levels in ergocryptine-treated enucleated rats were significantly (P < 0·02) decreased. Increases in N-POMC content of the pituitary lobe accompanied those of ACTH in animals 7, 10, 14 and 21 days after enucleation (P < 0·01 compared with sham-treatment). Anterior lobes from rats 10 days after enucleation or from adrenalectomized rats showed raised ACTH and N-POMC levels compared with sham-treated animals, whereas α-MSH content in the anterior lobe of enucleated rats was significantly (P < 0·005) decreased. Adrenalectomized animals had raised (P < 0·005) amounts of α-MSH compared with sham-treated animals. Plasma levels of ACTH and N-POMC were significantly (P < 0·01) raised in rats 10 days after enucleation or in adrenalectomized rats compared with those in sham-treated animals, whereas α-MSH levels were raised (P < 0·005) only in adrenalectomized rats. Sephadex G-75 chromatography of anterior lobe extracts obtained 10 days after surgery from sham-treated, enucleated and adrenalectomized rats was performed. In sham-treated animals the main N-POMC-immunoreactive peaks were located at the elution positions of N-POMC(1–95) and N-POMC (1–74), whereas in enucleated rats the bulk of the N-POMC immunoreactivity was located in a third peak which eluted at the position of synthetic N-POMC (1–48). In adrenalectomized rats a peak coinciding with the N-POMC(1–48) standard could also be detected, but the bulk of the N-POMC immunoreactivity corresponded to the N-POMC(1–95) and N-POMC(1–74) peaks. Perfusates from dispersed rat anterior pituitary cells from rats 10 days after enucleation or sham-operation were also chromatographed. The profile of N-POMC immunoreactivity was essentially the same as that in the anterior lobe extract. Chromatography of plasma samples from ergocryptine-treated enucleated rats revealed a peak accounting for N-POMC (1–74) and a peak coinciding with N-POMC(1–48). It was concluded that N-POMC peptides are physiologically important in adrenal regeneration and that, in this condition, mitogenically active N-POMC peptides are generated from the anterior lobe and not from the intermediate lobe of the pituitary gland. This implies a change in the mode of anterior lobe N-POMC processing in adrenal regeneration. J. Endocr. (1988) 116, 207–216

scholarly journals Identification of subcellular compartments containing peptidylglycine alpha-amidating monooxygenase in rat anterior pituitary

1995 ◽  
Vol 108 (1) ◽  
pp. 287-297 ◽  
Author(s):  
A.M. Oyarce ◽  
B.A. Eipper
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Gradient Centrifugation ◽  
Immunoblot Analysis ◽  
Subcellular Fractionation ◽  
Full Length ◽  
Pituitary Cells ◽  
Metabolic Labeling ◽  
Subcellular Compartments ◽  
Endoproteolytic Cleavage

Both soluble and integral membrane forms of peptidylglycine alpha-amidating monooxygenase (PAM) are expressed in the rat anterior pituitary, making it an ideal model system for studying the routing of proteins into secretory granules. To identify the subcellular compartments involved in the routing of integral membrane PAM, we used subcellular fractionation, metabolic labeling and immunoblot analysis. Mature secretory granules were found to contain full-length integral membrane PAM along with a significant amount of soluble PAM generated by endoproteolytic cleavage. PAM proteins were not co-distributed with tyrosylprotein sulfotransferase activity during sucrose gradient centrifugation, indicating that the trans-Golgi/TGN is not a major PAM-containing compartment at steady state. Fractionation of the 4,000 g and 10,000 g pellets obtained by differential centrifugation identified a significant amount of integral membrane PAM in a light fraction lacking soluble secretory granule proteins. Metabolic labeling experiments with primary anterior pituitary cells demonstrated that integral membrane PAM enters a light compartment with similar properties only after exit from the trans-Golgi/TGN. Comparison of the metabolic labeling and immunoblot analyses suggests that PAM in this post-trans-Golgi/TGN compartment is in organelles involved in the intracellular recycling of integral membrane PAM. Small amounts of full-length integral membrane PAM were also recovered in fractions containing internalized transferrin and may be in an endosomal compartment following retrieval from the cell surface.

Sign in / Sign up

Export Citation Format

Share Document