Functional integrity of anterior pituitary cells separated by a density gradient

1985 ◽  
Vol 109 (1) ◽  
pp. 25-31 ◽  
Author(s):  
B. Scheikl-Lenz ◽  
C. Markert ◽  
J. Sandow ◽  
L. Träger ◽  
H. Kuhl
Keyword(s):  
Density Gradient ◽  
Anterior Pituitary ◽  
Endocrine Cells ◽  
Culture Conditions ◽  
High Density ◽  
Immunocytochemical Staining ◽  
Pituitary Cells ◽  
Low Density ◽  
Sprague Dawley ◽  
Density Peak

Abstract. Using a continuous Percoll density gradient, endocrine cells of the anterior pituitary were separated. The cells were obtained from adult female Sprague-Dawley rats which had been ovariectomized for 7 days. The gradient revealed two equally sized populations of cells with densities of about 1.02 and 1.09 g/ml. Ninety-two per cent of the cellular GH content, 64% of LH, and 60% of TSH were found in the high density peak. Sixty-one per cent of the cellular Prl appeared in the low density peak. Immunocytochemical staining of the LH containing cells showed that 74% of the gonadotrophs were in the high density peak. After separation, the cells retained their responsiveness to LRH, TRH and GRF. Culture conditions influenced stimulated hormone release. Before stimulation, the cells were cultured either in tissue culture flasks (attached cells) or in Petri dishes (cells in suspension) for 3 days. After TRH-stimulation, suspended thyrotrophs released more TSH than attached thyrotrophs. Comparing the cells of both peaks, attached thyrotrophs of the high density peak showed higher stimulated TSH-release than those of the low density peak. The response of the gonadotrophs and somatotrophs to stimulation did not differ when culture conditions were changed. The present results demonstrate that the secretory activity of endocrine cells is influenced by culture conditions and should be evaluated fore each cell type.

Effect of cell density on growth hormone release from, cyclic AMP levels in and peptide α-amidation activity of primary cultured rat anterior pituitary cells

1991 ◽  
Vol 131 (2) ◽  
pp. 237-NP ◽  
Author(s):  
H. Sugimoto ◽  
M. Suzuki ◽  
T. Takeuchi ◽  
K. Ishikawa
Keyword(s):  
Cyclic Amp ◽  
Cell Density ◽  
Anterior Pituitary ◽  
High Density ◽  
Pituitary Cells ◽  
Low Density ◽  
Camp Content ◽  
Gh Secretion ◽  
Cellular Concentration ◽  
Incubation System

ABSTRACT To investigate the effect of cell density on rat somatotrophs, dispersed adult rat anterior pituitary cells were plated at several densities (0·6, 1·2, 2·4 and 6·0 × 105 cells/cm2) or at two densities (6·07 × 105 and 1·21 × 105 cells/cm2) as high and low densities respectively. A static incubation system was used to study the release of GH and peptidyl glycine α-amidating enzyme (PAM; a component of secretory granules) and the cellular concentration of cyclic AMP (cAMP) in basal and stimulated cells. In addition, a perifusion system was used to characterize the sensitivity to GH-releasing factor (GRF) at both high and low densities. The high density of cells in both the static incubation and perifusion systems caused a low basal secretion rate of GH and PAM. When the cultured cells were stimulated with human GRF (hGRF) in perifusion, GH secretion from cells at high density was markedly higher than that from cells at low density. The cAMP content in the static incubation system showed a similar tendency to that observed for basal and stimulated GH secretion; that is, the basal cAMP content was increased as the cell density decreased. The cellular concentration of cAMP was increased by about threefold by 1 nmol hGFR/1 and by more than tenfold by 10 nmol hGRF/1. When the medium from cells cultured at low density was replaced by that from the cells at high density, there was no change in the basal cellular cAMP content of the cells at low density. These data suggest that cell-to-cell contact in dispersed pituitary cells seems to be important in the maintenance of their cellular integrity to secrete GH. Journal of Endocrinology (1991) 131, 237–244

scholarly journals Potensi Hipolipidemik Yogurt dari Isolat Protein Biji Kecipir (Psophocarpus tetragonolobus) pada Tikus Hiperkolesterol dengan Perlakuan Jumlah Pakan

2017 ◽  
Vol 37 (1) ◽  
pp. 1
Author(s):  
Agus Slamet ◽  
Bayu Kanetro
Keyword(s):  
High Density Lipoprotein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Protein Isolate ◽  
High Density ◽  
Winged Bean ◽  
Low Density ◽  
Sprague Dawley ◽  
High Concentration

Protein content of winged bean is almost the same as soybean, but the beany flavor is more poweful than soybean. Therefore the protein of winged bean was isolated prior to use as raw material of yogurt. This research was aimed to determine the potency of  hypocholestrolemic activity of yogurt protein isolate of winged  bean through in vivo bioassay by using Sprague Dawley male rats. The treatments of the research were yogurt feed treatment with concentration of yogurt 0 (standard feed without yogurt as a control), 2, and 4 g yogurt/day as low and high concentration treatment respectively for 4th weeks after hypercholesterol feed  treatment for 1 week. The blood lipid profile of rats, including triglyceride, cholesterol total, High Density Lipoprotein (HDL), Low  Density Lipoprotein (LDL) cholesterol were analysed on the 2nd  and 4th weeks for the yogurt feed treatment while for before  yogurt feed treatment, the evaluation were based on the  adaptation phase and the 1st week for hypercholesterol phase.  The result of this research showed that the blood triglyceride,  cholesterol total, LDL increased, and the blood HDL decreased in hypercholesterol phase before yogurt feed treatment. The potency of hypocholestrolemic of yogurt from protein isolate of winged  bean was shown by the decreasing of blood triglyceride,  cholesterol total, LDL and increasing the HDL cholesterol after the yogurt feed treatment with low and high concentration. That  indicated that yogurt that was made of protein isolate of winged  bean could reduced cholesterol. ABSTRAKBiji kecipir memiliki kadar protein yang hampir sama dengan  kedelai, namun bau langunya lebih tajam daripada kedelai,  sehingga perlu diisolasi proteinnya sebelum digunakan sebagai  bahan baku yogurt. Tujuan penelitian ini adalah menentukan  potensi hipokolesterolemik yogurt isolat proteun biji kecipir  melalui uji biologis in vivo menggunakan tikus jantan Sprague Dawley. Perlakuan penelitian ini adalah perlakuan pakan yogurt  dengan konsentrasi 0 (pakan standar tanpa penambahan yogurt sebagai kontrol), 2, dan 4 g yogurt/hari berturut-turut sebagai  perlakuan konsentrasi rendah dan tinggi selama 4 minggu  perlakuan pakan yogurt sesudah pemberian pakan hiperkolesterol selama 1 minggu. Profil lipida darah tikus meliputi kadar trigliserida, total kolesterol, kolesterol High Density  Lipoprotein (HDL), dan Low Density Lipoprotein (LDL) dianalisis  pada minggu ke 2 dan 4 minggu selama perlakuan pakan yogurt  dan sebelum perlakuan pakan yogurt yaitu pada fase pemeliharaan adaptasi dan 1 minggu pada fase pemeliharan  hiperkolesterol. Hasil penelitian ini menunjukkan bahwa  trigliserida, total kolesterol, dan kolesterol LDL meningkat dan kolesterol HDL menurun selama fase pemberian pakan  hiperkolesterol sebelum perlakuan pakan yogurt. Potensi  hipokolesterol yogurt isolat protein biji kecipir ditunjukkan dengan penurunan trigliserida, total kolesterol, dan kolesterol LDL, serta peningkatan kolesterol HDL sesudah perlakuan pakan yogurt dengan konsentrasi rendah maupun tinggi. Hal tersebut mengindikasikan bahwa yogurt isolat protein biji kecipir mampu menurunkan kolesterol.

scholarly journals Thyroid hormone uptake in cultured rat anterior pituitary cells: effects of energy status and bilirubin

2000 ◽  
Vol 165 (3) ◽  
pp. 599-606 ◽  
Author(s):  
FW Wassen ◽  
EP Moerings ◽  
H van Toor ◽  
G Hennemann ◽  
ME Everts
Keyword(s):  
Thyroid Hormone ◽  
Critically Ill Patients ◽  
Anterior Pituitary ◽  
Culture Conditions ◽  
Pituitary Cells ◽  
Atp Content ◽  
Energy Status ◽  
Inhibitory Effects ◽  
Anterior Pituitary Cells ◽  
Energy Deprivation

Transport of thyroxine (T(4)) into the liver is inhibited in fasting and by bilirubin, a compound often accumulating in the serum of critically ill patients. We tested the effects of chronic and acute energy deprivation, bilirubin and its precursor biliverdin on the 15-min uptake of [(125)I]tri-iodothyronine ([(125)I]T(3)) and [(125)I]T(4) and on TSH release in rat anterior pituitary cells maintained in primary culture for 3 days. When cells were cultured and incubated in medium without glucose and glutamine to induce chronic energy deprivation, the ATP content was reduced by 45% (P<0. 05) and [(125)I]T(3) uptake by 13% (NS), but TSH release was unaltered. Preincubation (30 min) and incubation (15 min) with 10 microM oligomycin reduced ATP content by 51% (P<0.05) and 53% (P<0. 05) under energy-rich and energy-poor culture conditions respectively; [(125)I]T(3) uptake was reduced by 66% (P<0.05) and 64% (P<0.05). Neither bilirubin nor biliverdin (both 1-200 microM) affected uptake of [(125)I]T(3) or [(125)I]T(4). Bilirubin (1-50 microM) did not alter basal or TRH-induced TSH release. In conclusion, the absence of inhibitory effects of chronic energy deprivation and bilirubin on thyroid hormone uptake by pituitary cells supports the view that the transport is regulated differently than that in the liver.

Cytoprotective Effect of ICL670 (Deferasirox) on At20 Endocrine Cells Susceptible to Iron-Evoked Oxidative Damage.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3825-3825
Author(s):  
Hava Glickstein ◽  
Hanspeter Nick ◽  
Zvi Loav Cabantchik
Keyword(s):  
Endocrine Cells ◽  
Iron Chelation ◽  
Culture Conditions ◽  
Cardiac Cells ◽  
Functional Restoration ◽  
Pituitary Cells ◽  
Oxygen Intermediates ◽  
Microscopy Imaging ◽  
Cell Functions ◽  
Metal Catalyzed

Abstract A major cause of biological damage associated with tissue iron accumulation is the cellular acquisition of circulating labile plasma iron (LPI) by endocytic mechanisms and ensuing metal-catalyzed oxidations. Endocrine cells are presumed to have endocytic abilities and/or high susceptibility to the formation of reactive oxygen intermediates (ROIs), particularly those generated in the presence of labile iron. As these properties might be implicated in the early onset of endocrine dysfunctions observed in transfusional hemosiderosis, a major goal of iron chelation therapy is to prevent iron ingress into endocrine cells and ensuing toxicity and/or removal of cell-accumulated iron. Such properties of chelators have been afforded in cardiac cells (Glickstein et al. 2006, Blood In press) by treating LPI-carrying plasma with pharmacologically attainable concentrations of orally active iron chelators in clinical practice. The latter also evoked neutralization of metal-catalyzed ROS formation, by iron chelation and extrusion from cells and thereby supported cardiac functional restoration. We explored here whether addition of ICL670 (deferasirox) could rescue acutely iron-overloaded At20 pituitary cells from iron-toxicity, using fluorescence-plate reader and microscopy-imaging for live monitoring of cell functions and assessing toxicity in terms of:cell integrity (calcein cell retention assay);metabolic activities (mitochondrial Alamar-Blue assay); andintracellular (ACTH) hormone levels. Our studies indicate that in cell culture conditions and at pharmacological chelator concentrations, ICL670 can preserve both At20 endocrine cell viability and functional properties that were compromised by iron-catalyzed formation of ROIs.

scholarly journals The Evaluation of Islet Purification Methods That Use Large Bottles to Create a Continuous Density Gradient

Cell Medicine ◽  
2017 ◽  
Vol 9 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
Chika Miyagi-Shiohira ◽  
Naoya Kobayashi ◽  
Issei Saitoh ◽  
Masami Watanabe ◽  
Yasufumi Noguchi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Density Gradient ◽  
Stimulation Index ◽  
High Density ◽  
Steel Pipe ◽  
High Yield ◽  
Low Density ◽  
Pancreatic Islet Transplantation ◽  
Continuous Density ◽  
Stainless Steel Pipe

Islet purification is one of the most important steps of islet isolation for pancreatic islet transplantation. The most common method of islet purification is density gradient centrifugation using a COBE 2991 cell processor. However, this method can damage islets mechanically through its high shearing force. We recently reported that a new purification method using large plastic bottles effectively achieves a high yield of islets from the porcine pancreas. In the present study, we evaluated the methods of making a continuous density gradient. The gradient was produced with a gradient maker and two types of candy cane-shaped stainless steel pipes. One method was to use a “bent-tipped” stainless steel pipe and to load from a high-density solution to a low-density solution, uploading the stainless steel pipe. The other method was to use a regular stainless steel pipe and to load from a low-density solution to a high-density solution, leaving the stainless steel pipe in place. There were no significant differences between the two solutions in terms of the islet yield, rate of viability or purity, score, or the stimulation index after purification. Furthermore, there were no differences in the attainability or suitability of posttransplantation normoglycemia. Our study shows the equivalency of these two methods of islet purification.

scholarly journals Human Growth Hormone-Releasing Factor (hGRF)1–29-Albumin Bioconjugates Activate the GRF Receptor on the Anterior Pituitary in Rats: Identification of CJC-1295 as a Long-Lasting GRF Analog

Endocrinology ◽  
2005 ◽  
Vol 146 (7) ◽  
pp. 3052-3058 ◽  
Author(s):  
Lucie Jetté ◽  
Roger Léger ◽  
Karen Thibaudeau ◽  
Corinne Benquet ◽  
Martin Robitaille ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Half Life ◽  
Anterior Pituitary ◽  
Ex Vivo ◽  
Normal Male ◽  
Pituitary Cells ◽  
Sprague Dawley ◽  
Plasma Half Life

Abstract In vivo bioconjugation to the free thiol on Cys34 of serum albumin by a strategically placed reactive group on a bioactive peptide is a useful tool to extend plasma half-life. Three maleimido derivates of human GH-releasing factor (hGRF)1–29 were synthesized and bioconjugated to human serum albumin ex vivo. All three human serum albumin conjugates showed enhanced in vitro stability against dipeptidylpeptidase-IV and were bioactive in a GH secretion assay in cultured rat anterior pituitary cells. When the maleimido derivatives were individually administered sc to normal male Sprague Dawley rats, an acute secretion of GH was measured in plasma. The best compound, CJC-1295, showed a 4-fold increase in GH area under the curve over a 2-h period compared with hGRF1–29. CJC-1295, a tetrasubstituted form of hGRF1–29 with an added Nε-3-maleimidopropionamide derivative of lysine at the C terminus, was selected for further pharmacokinetic evaluation, where it was found to be present in plasma beyond 72 h. A Western blot analysis of the plasma of a rat injected with CJC-1295 showed the presence of a CJC-1295 immunoreactive species on the band corresponding to serum albumin, appearing after 15 min and remaining in circulation beyond 24 h. These results led to the identification of CJC-1295 as a stable and active hGRF1–29 analog with an extended plasma half-life.

Heme Oxygenase in the Rat Anterior Pituitary: Immunohistochemical Localization and Possible Role in Gonadotropin and Prolactin Secretion

2003 ◽  
Vol 228 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Iulia C. Alexandreanu ◽  
David M. Lawson
Keyword(s):  
Heme Oxygenase ◽  
Anterior Pituitary ◽  
Immunohistochemical Localization ◽  
Prolactin Secretion ◽  
Pituitary Cells ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Lh Release

The objectives of this study were to determine if heme oxygenase (HO), which catalyzes the degradation of heme and the formation of carbon monoxide (CO), is localized in the rat anterior pituitary and, if so, to determine if hemin (a substrate for HO) or chromium mesoporphyrin (CrMP) (an inhibitor of HO), alter pituitary gonadotropin and prolactin secretion. For localization of HO, sections of anterior pituitaries obtained from mature Holtzman Sprague-Dawley rats in different stages of the estrous cycle were immunostained for two of the HO isoforms, HO-1 and HO-2. The immunostaining for the inducible HO isoform (HO-1) was limited to discrete populations of pituitary cells, whereas the constitutive isoform (HO-2) had a more widespread distribution. The afternoon surge of leutinizing hormone (LH) in the plasma of ovariectomized, estradiol-treated rats was advanced by 2 hr after 7 days of treatment with CrMP (4 μM/kg), and this effect was reversed when hemin (30 μM/kg) was coadministered with CrMP. The afternoon follicle-stimulating hormone (FSH) surge was not affected by either treatment. In contrast, the afternoon prolactin (PRL) surge was completely blocked or delayed by CrMP treatment, and this effect was not reversed by hemin. In vitro perifusion of pituitary explants with CrMP also significantly reduced PRL release compared with secretion from untreated explants. In vitro gonadotropin-releasing hormone (GnRH)-stimulated FSH secretion was significantly increased from pituitary explants of ovariectomized, estradiol-treated rats treated in vivo with hemin but was unaffected by CrMP treatment, whereas GnRH-stimulated LH release was not affected by hemin but was increased by CrMP treatment. In conclusion, this study demonstrates that HO exists in the rat anterior pituitary gland, and that a substrate and an inhibitor of this enzyme alter the secretion of gonadotropins and PRL.

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