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.

Synaptobrevin isoforms in secretory granules and synaptic-like microvesicles in anterior pituitary cells

Life Sciences ◽  
1998 ◽  
Vol 62 (7) ◽  
pp. 607-616 ◽  
Author(s):  
Glòria Majó ◽  
Fernando Aguado ◽  
Juan Blasi ◽  
Jordi Marsal
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Pituitary Cells ◽  
Anterior Pituitary Cells

scholarly journals Detection of insulin synthesis in mammalian anterior pituitary cells by immunohistochemistry and demonstration of insulin-related transcripts by in situ RNA-DNA hybridization.

1986 ◽  
Vol 34 (5) ◽  
pp. 673-678 ◽  
Author(s):  
G C Budd ◽  
B Pansky ◽  
B Cordell
Keyword(s):  
Growth Hormone ◽  
Nucleic Acid ◽  
Dna Hybridization ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Pituitary Cells ◽  
Insulin Synthesis ◽  
Anterior Pituitary Cells ◽  
Pancreatic B Cells

Insulin or highly homologous transcripts is shown to be synthesized in cultures of mammalian anterior pituitary cells using cloned insulin-specific cDNA probes and nucleic acid cytochemistry. The insulin-hybridizing cells are less abundant than the growth hormone-producing cells, occurring in the cultures at approximately one tenth the frequency. Immunocytochemistry demonstrates that insulin or insulin-like proteins is also synthesized by the cultured pituitary cells and that the insulin immunoreactivity is contained within secretory granules. It appears that many of these secretory granules are concentrated around the periphery of the cell, unlike the insulin-containing granules in pancreatic B-cells.

Localization of Somatostatin Receptors in Secretion Vesicles in Anterior Pituitary Cells and Pancreatic Islets

1985 ◽  
Vol 5 (1) ◽  
pp. 83-103 ◽  
Author(s):  
Boris Draznin ◽  
Philip S. Mehler ◽  
J. Wayne Leitner ◽  
Karl E. Sussman ◽  
Rolf Dahl ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Anterior Pituitary ◽  
Somatostatin Receptors ◽  
Pituitary Cells ◽  
Anterior Pituitary Cells

Dopamine enters lactotrophs and reaches their secretory granules

1985 ◽  
Vol 104 (1) ◽  
pp. 23-NP ◽  
Author(s):  
M. G. P. Gallardo ◽  
M. Bilinski ◽  
S. R. Chiocchio ◽  
J. H. Tramezzani
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Pituitary Cells ◽  
Histochemical Reaction ◽  
Anterior Pituitary Cells ◽  
Biochemical Assays ◽  
Pituitary Lactotroph

ABSTRACT The presence of dopamine in the lactotroph cell, as well as in isolated prolactin secretory granules, was demonstrated by means of an histochemical reaction for electron microscopy. Biochemical assays further confirmed the presence of dopamine in the secretory granules. Autoradiographic preparations examined by light microscopy showed dopamine internalization in dispersed anterior pituitary cells. Isolated anterior pituitary lactotroph cells incorporated more [3H]dopamine than a fraction containing other anterior pituitary cells. J. Endocr. (1985) 104, 23–28

scholarly journals Immunocytochemical localization of atrial natriuretic factor in the kidney, adrenal medulla, pituitary, and atrium of rat.

1985 ◽  
Vol 33 (8) ◽  
pp. 828-832 ◽  
Author(s):  
J C McKenzie ◽  
I Tanaka ◽  
K S Misono ◽  
T Inagami
Keyword(s):  
Adrenal Medulla ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Immunocytochemical Localization ◽  
Atrial Myocytes ◽  
Collecting Tubules ◽  
Sodium Regulation ◽  
Sites Of Action ◽  
A Site ◽  
Atrial Natriuretic

Mammalian atria have previously been shown to produce a variety of peptides with natriuretic and vasorelaxant activities. Certain of these atrial natriuretic factors (ANF) have been localized immunocytochemically in secretory granules of atrial myocytes. However, the precise sites of action and extra-atrial synthesis or accumulation of ANF have not been identified immunocytochemically. In the present study, immunoreactive ANF was detected in rat atrial myocytes, intercalated cells of the renal collecting ducts, adrenal medullary chromaffin cells, and gonadotrophs of the anterior pituitary using an antibody against synthetic rat ANF-IV (H2N-Arg-Ser-Ser-Cys-Phe-Gly- Gly-Arg-Ile-Asp-Arg-Ile-Gly-Ala-Gln-Ser-Gly-Leu-Gly-Cys-Asn-Ser-Phe- Arg-Try-COOH). The localization of ANF in specialized cells of the renal collecting tubules and ducts supports suggestions that these structures may be a site of natriuretic action of ANF. In addition, immunocytochemical localization of ANF in the rat adrenal medulla and anterior pituitary suggests the existence of alternate sites of action and/or synthesis. We believe these findings are important for a more complete understanding of the role of ANF in fluid and sodium regulation and of the participation of ANF in the development of sodium-dependent hypertension.

scholarly journals Cell Type-Specific Metabolism of Peptidylglycineα -Amidating Monooxygenase in Anterior Pituitary*

Endocrinology ◽  
2000 ◽  
Vol 141 (8) ◽  
pp. 3020-3034 ◽  
Author(s):  
Rajaa El Meskini ◽  
Richard E. Mains ◽  
Betty A. Eipper
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Primary Cultures ◽  
Cell Types ◽  
Pituitary Cell ◽  
Male Rat ◽  
Pituitary Cells ◽  
Cell Type ◽  
Cell Content ◽  
Monooxygenase Activity

Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme expressed in each major anterior pituitary cell type. We used primary cultures of adult male rat anterior pituitary to examine PAM expression, processing, and secretion in the different pituitary cell types and to compare these patterns to those observed in transfected AtT-20 corticotrope tumor cells. Immunostaining and subcellular fractionation identified PAM in pituitary secretory granules and additional vesicular compartments; in contrast, in AtT-20 cells, transfected PAM was primarily localized to the trans-Golgi network. PAM expression was highest in gonadotropes, with moderate levels in somatotropes and thyrotropes and lower levels in corticotropes and lactotropes. Under basal conditions, less than 1% of the cell content of monooxygenase activity was secreted per h, a rate comparable to the basal rate of release of individual pituitary hormones. General secretagogues stimulated PAM secretion 3- to 5-fold. Stimulation with specific hypothalamic releasing hormones demonstrated that different pituitary cell types secrete characteristic sets of PAM proteins. Gonadotropes and thyrotropes release primarily monofunctional monooxygenase. Somatotropes secrete primarily bifunctional PAM, whereas corticotropes secrete a mixture of mono- and bifunctional proteins. As observed in transfected AtT-20 cells, pituitary cells rapidly internalize the PAM/PAM-antibody complex from the cell surface. The distinctly different steady-state localizations of endogenous PAM in primary pituitary cells and transfected PAM in AtT-20 cell lines may simply reflect the increased storage capacity of primary pituitary cells.

scholarly journals Distribution of a novel peptide in the anterior pituitary, gastric pyloric gland, and pancreatic islets of rat.

1992 ◽  
Vol 40 (2) ◽  
pp. 221-229 ◽  
Author(s):  
T Yamamoto ◽  
N Katsumata ◽  
K Tachibana ◽  
H G Friesen ◽  
J I Nagy
Keyword(s):  
Pancreatic Islets ◽  
Anterior Pituitary ◽  
Islet Cells ◽  
Cell Types ◽  
Pituitary Cells ◽  
Intact Cells ◽  
Rat Pituitary ◽  
Altered Form ◽  
Immunofluorescence Labeling

We used Western blot and immunohistochemical methods to investigate the biochemical characteristics and cellular distribution of a novel peptide (peptide 23) that was previously shown to be released from anterior pituitary cells of rat in response to growth hormone-releasing hormone. In the pituitary, peptide 23 isolated from intact cells had an Mr of 31,000, whereas that released into culture medium had an Mr of 16,000. Pancreatic islets contained a 19 KD form of the peptide. Immunohistochemically, peptide 23 in the rat pituitary gland was localized in a subpopulation of somatotropes. In pancreatic islets, the peptide was found by triple immunofluorescence labeling to be present in both insulin- and somatostatin-containing cells. In the gastrointestinal tract, peptide 23 was found only in a subpopulation of endocrine cells in the pyloric glands. This subpopulation of cells was found to be entirely separate from those containing either serotonin or somatostatin, and may represent one of the other known or as yet biochemically uncharacterized cell types in this gland. The results suggest that in response to secretagogues in vitro, an altered form of the peptide is secreted from pituitary cells and that an intracellular form of peptide 23 is expressed in some but not all somatotropes, a large proportion of islet cells, and a distinct population of pyloric cells.

Differential association of endogenous proenkephalin-derived peptides with membranes of microsomes from rat striatum, adrenal medulla and heart ventricle

1990 ◽  
Vol 5 (2) ◽  
pp. 175-183 ◽  
Author(s):  
O. Vindrola ◽  
A. Ase ◽  
R. Aloyz ◽  
F. Saravia ◽  
S. Finkielman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Adrenal Medulla ◽  
Secretory Granules ◽  
Enzymatic Digestion ◽  
Rat Striatum ◽  
Heart Ventricle ◽  
Carboxypeptidase B ◽  
Molecular Weights ◽  
Chromatographic Profile ◽  
Microsomal Membranes

ABSTRACT Proenkephalin-derived peptides, in common with other prohormones, are associated with membranes of microsomes and secretory granules in the bovine adrenal medulla. Post-translational processing of the precursor molecule varies depending upon the tissue. The relationship between post-translational events in different tissues was examined by studying the membrane association of endogenous proenkephalin-derived peptides in the crude microsomal fraction of rat adrenal medulla, brain striatum and heart ventricle. [Met]-Enkephalin and synenkephalin (proenkephalin(1–70)) immunoreactivities were quantified by radioimmunoassay after sequential enzymatic digestion with trypsin and carboxypeptidase B. Between 60 and 75% of total immunoreactive peptides present in intact microsomes of the three tissues were associated with membranes and specifically released with 2 m KSCN (pH 7·4). Analysis of the chromatographic profile of materials present in the soluble and associated fractions produced the following results. In the three tissues the materials associated with microsomal membranes corresponded to peptides larger than 3–5 kDa and displayed synenkephalin and [Met]-enkephalin immunoreactivity. Adrenal and heart microsomes showed a continuous pattern of membrane-associated proenkephalin-derived peptides of high, intermediate and low molecular weights containing the synenkephalin and [Met]-enkephalin sequences. These tissues, however, presented quantitative differences, as the highest concentrations belonged to materials larger and smaller than 12·5 kDa in adrenal and heart microsomes respectively. On the other hand, brain striatal microsomes displayed a discontinuous pattern of associated materials, with the absence of some products of high and intermediate molecular weight. Only in the soluble fraction of striatal microsomes were peptides detected of high and intermediate molecular weight containing the [Met]-enkephalin but not the synenkephalin sequence. In conclusion, this study demonstrates that the association of proenkephalin-derived peptides with microsomal membranes is a common event in the adrenal medulla, heart ventricle and rat striatum, involving, in all cases, some portion of the C-terminal sequence of the synenkephalin molecule. These observations provide further evidence suggesting that the differential profiles of proenkephalin-derived peptides in the adrenal medulla and striatum may be related to differential post-translational processing instead of changes in processing rate.

Evidence for direct action of calcitonin in the rat pituitary gland

1989 ◽  
Vol 120 (5) ◽  
pp. 682-688 ◽  
Author(s):  
G. Morel ◽  
J.-G. Chabot ◽  
A. Enjalbert ◽  
M. Priam ◽  
P. M. Dubois
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Direct Action ◽  
Secretory Granules ◽  
In Vitro Study ◽  
Male Rat ◽  
Pituitary Cells ◽  
Cytoplasmic Matrix ◽  
Rat Pituitary

Abstract. Classic concepts of calcitonin (CT) function have focused on the effects of CT on calcium homeostasis. More recently CT actions on brain and pituitary have been investigated. In order to evaluate the effects of CT on the anterior pituitary gland we studied the action(s) of CT in vitro and visualized endogenous CT in adult male rat pituitary gland by immunocytochemistry on ultrathin sections obtained by cryoultramicomy. In vitro study using dispersed anterior pituitary cells indicated that CT stimulated the secretion of PRL, whereas the secretion of GH, TSH and LH was not affected. CT-like immunoreactivity was observed in lactotropes only. The other pituitary cell types were not immunoreactive. In lactotropes, immunostaining was observed in the cytoplasm and in the nucleus. In the cytoplasm, CT-like immunoreactivity was visuzalized in the cytoplasmic matrix and in the secretory granules. In the nucleus, immunostaining was distributed primarly in the euchromatin, in the vincinity of heterochromatin region. CT-like immunoreactivity was also observed at the plasma membrane but was only scarce. No reaction product was found when anti-CT serum pre-incubated with CT was used. In conclusion, these results bring evidence for a direct action of CT on lactotrope regulation in vitro as well as in intact animals.

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