5-Hydroxytryptamine synthesis, storage, and secretion from rat pancreatic acinar cells

1984 ◽  
Vol 62 (7) ◽  
pp. 755-761 ◽  
Author(s):  
Pierre Falardeau ◽  
Seymour Heisler
Keyword(s):  
Biological Function ◽  
De Novo ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Zymogen Granules ◽  
De Novo Synthesis ◽  
Concentration Dependent Manner ◽  
Granule Fraction ◽  
Stimulation Of

Pancreatic acinar cells are known to synthesize serotonin and dopamine from extracellular precursors. In this study, we found that small amounts of serotonin, alone, were preferentially stored in zymogen granules of acinar cells. Serotonin was apparently incorporated into mature rather than newly formed granules. This was based on the fact that the amine, rather than the newly synthesized zymogen protein, appeared first in the purified granule fraction; additionally, concentrations of cycloheximide, which markedly inhibited de novo synthesis of zymogen protein, did not affect the incorporation of serotonin into the granule fraction. Serotonin, synthesized by the acinar cells, can be secreted along with amylase in a time- and concentration-dependent manner following stimulation of acinar cells by a variety of pancreatic secretagogues. Whether serotonin secreted into pancreatic juice has a biological function remains unknown.

CRHSP-24 phosphorylation is regulated by multiple signaling pathways in pancreatic acinar cells

2003 ◽  
Vol 285 (4) ◽  
pp. G726-G734 ◽  
Author(s):  
Claus Schäfer ◽  
Hanna Steffen ◽  
Karen J. Krzykowski ◽  
Burkhard Göke ◽  
Guy E. Groblewski
Keyword(s):  
Signaling Pathways ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Calyculin A ◽  
Concentration Dependent Manner ◽  
Pancreatic Acini ◽  
Heat Stable ◽  
Heat Stable Protein ◽  
Mrna Binding

Ca2+-regulated heat-stable protein of 24 kDa (CRHSP-24) is a serine phosphoprotein originally identified as a physiological substrate for the Ca2+-calmodulin regulated protein phosphatase calcineurin (PP2B). CRHSP-24 is a paralog of the brain-specific mRNA-binding protein PIPPin and was recently shown to interact with the STYX/dead phosphatase protein in developing spermatids (Wishart MJ and Dixon JE. Proc Natl Acad Sci USA 99: 2112–2117, 2002). Investigation of the effects of phorbol ester (12- o-tetradecanoylphorbol-13-acetate; TPA) and cAMP analogs in 32P-labeled pancreatic acini revealed that these agents acutely dephosphorylated CRHSP-24 by a Ca2+-independent mechanism. Indeed, cAMP- and TPA-mediated dephosphorylation of CRHSP-24 was fully inhibited by the PP1/PP2A inhibitor calyculin A, indicating that the protein is regulated by an additional phosphatase other than PP2B. Supporting this, CRHSP-24 dephosphorylation in response to the Ca2+-mobilizing hormone cholecystokinin was differentially inhibited by calyculin A and the PP2B-selective inhibitor cyclosporin A. Stimulation of acini with secretin, a secretagogue that signals through the cAMP pathway in acini, induced CRHSP-24 dephosphorylation in a concentration-dependent manner. Isoelectric focusing and immunoblotting indicated that elevated cellular Ca2+ dephosphorylated CRHSP-24 on at least three serine sites, whereas cAMP and TPA partially dephosphorylated the protein on at least two sites. The cAMP-mediated dephosphorylation of CRHSP-24 was inhibited by low concentrations of okadaic acid (10 nM) and fostriecin (1 μM), suggesting that CRHSP-24 is regulated by PP2A or PP4. Collectively, these data indicate that CRHSP-24 is regulated by diverse and physiologically relevant signaling pathways in acinar cells, including Ca2+, cAMP, and diacylglycerol.

scholarly journals Alcohols enhance caerulein-induced zymogen activation in pancreatic acinar cells

2002 ◽  
Vol 282 (3) ◽  
pp. G501-G507 ◽  
Author(s):  
Zhao Lu ◽  
Suresh Karne ◽  
Thomas Kolodecik ◽  
Fred S. Gorelick
Keyword(s):  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Zymogen Activation ◽  
Concentration Dependent Manner ◽  
Pancreatic Acini ◽  
A Chain ◽  
Peak Value

Activation of zymogens within the pancreatic acinar cell is an early feature of acute pancreatitis. Supraphysiological concentrations of cholecystokinin (CCK) cause zymogen activation and pancreatitis. The effects of the CCK analog, caerulein, and alcohol on trypsin and chymotrypsin activation in isolated pancreatic acini were examined. Caerulein increased markers of zymogen activation in a time- and concentration-dependent manner. Notably, trypsin activity reached a peak value within 30 min, then diminished with time, whereas chymotrypsin activity increased with time. Ethanol (35 mM) sensitized the acinar cells to the effects of caerulein (10−10 to 10−7 M) on zymogen activation but had no effect alone. The effects of ethanol were concentration dependent. Alcohols with a chain length of ≥2 also sensitized the acinar cell to caerulein; the most potent was butanol. Branched alcohols (2-propanol and 2-butanol) were less potent than aliphatic alcohols (1-propanol and 1-butanol). The structure of an alcohol is related to its ability to sensitize acinar cells to the effects of caerulein on zymogen activation.

Role of PKC-δ on substance P-induced chemokine synthesis in pancreatic acinar cells

2008 ◽  
Vol 294 (3) ◽  
pp. C683-C692 ◽  
Author(s):  
Raina Devi Ramnath ◽  
Jia Sun ◽  
Sharmila Adhikari ◽  
Liang Zhi ◽  
Madhav Bhatia
Keyword(s):  
Substance P ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Activator Protein 1 ◽  
Concentration Dependent Manner ◽  
Chemokine Production ◽  
Monocyte Chemoattractant Protein 1 ◽  
Inflammatory Protein ◽  
Neurokinin 1

Interaction of the neuropeptide substance P (SP) with its high-affinity neurokinin-1 receptor (NK1R) plays an important role in the pathophysiology of acute pancreatitis. SP is known to stimulate the production of chemokines monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1α, and MIP-2 in pancreatic acinar cells via the activation of NF-κB. However, the signaling mechanisms by which the SP-NK1R interaction induces NF-κB activation and chemokine production remain unclear. To that end, in the present study, we investigated the participation of PKC in SP-induced chemokine production in pancreatic acinar cells. In this study, we showed that SP stimulated an early phosphorylation of PKC isoform PKC-δ followed by increased activation of MAPKKK MEKK1 and MAPK ERK and JNK as well as transcription factor NF-κB and activator protein-1 driven chemokine production. Depletion of PKC-δ with its inhibitor rottlerin or the specific PKC-δ translocation inhibitor peptide dose dependently decreased SP-induced PKC-δ, MEKK1, ERK, JNK, NF-κB, and AP-1 activation. Moreover, rottlerin as well as PKC-δ translocation inhibitor inhibited SP-induced chemokine production in a concentration-dependent manner. We also demonstrated that PKC-δ activation was attenuated by CP96345, a selective NK1R antagonist, thus showing that PKC-δ activation was indeed mediated by SP in pancreatic acinar cells. These results show that PKC-δ is an important proinflammatory signal transducer for SP-NK1R-induced chemokine production in pancreatic acinar cells.

2, 4, 5-Trideoxyhexopyranosides Derivatives of 4’- Demethylepipodophyllotoxin: De novo Synthesis and Anticancer Activity

2020 ◽  
Vol 16 ◽  
Author(s):  
Yapeng Lu ◽  
Li Zhu ◽  
Rui Cai ◽  
Yu Li ◽  
Yu Zhao
Keyword(s):  
Cell Cycle ◽  
Cancer Cell ◽  
De Novo ◽  
Building Blocks ◽  
Dependent Manner ◽  
De Novo Synthesis ◽  
Concentration Dependent Manner ◽  
Cycle Arrest ◽  
M Phase ◽  
Derivatives Of

Background: Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine. Objective: The present work was aimed to design and synthesize a series of 2, 4, 5-trideoxyhexopyranosides derivatives of 4’-demethylepipodophyllotoxin as novel anticancer agents. Methods: A divergent de novo synthesis of 2, 4, 5-trideoxyhexopyranosides derivatives of 4’-demethylepipodophyllotoxin has been established via palladium-catalyzed glycosylation. The abilities of synthesized glycosides to inhibit the growth of A549, HepG2, SH-SY5Y, KB/VCR and HeLa cancer cells were investigated by MTT assay. Flow cytometric analysis of cell cycle with propidium iodide DNA staining was employed to observe the effect of compound 5b on cancer cell cycle. Results: Twelve D and L monosaccharides derivatives 5a-5l have been efficiently synthesized in three steps from various pyranone building blocks employing de novo glycosylation strategy. D-monosaccharide 5b showed highest cytotoxicity on five cancer cell lines with the IC50 values from 0.9 to 6.7 mM. It caused HepG2 cycle arrest at G2/M phase in a concentration-dependent manner. Conclusion: The present work leads to the development of novel 2, 4, 5-trideoxyhexopyranosides derivatives of 4’- demethylepipodophyllotoxin. The biological results suggested that the replacement of the glucosyl moiety of etoposide with 2, 4, 5-trideoxyhexopyranosyl is favorable to their cytotoxicity. D-monosaccharide 5b caused HepG2 cycle arrest at G2/M phase in a concentration-dependent manner.

Pilocarpine and carbachol exhibit markedly different patterns of Ca2+ signaling in rat pancreatic acinar cells

1993 ◽  
Vol 264 (4) ◽  
pp. G786-G791 ◽  
Author(s):  
D. I. Yule ◽  
T. E. Essington ◽  
J. A. Williams
Keyword(s):  
Partial Agonist ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Muscarinic Agonist ◽  
Dependent Manner ◽  
Maximal Concentration ◽  
Concentration Dependent Manner ◽  
Amylase Release ◽  
Pancreatic Acini ◽  
Pi Hydrolysis

The effects of the partial muscarinic agonist pilocarpine on physiological responses were investigated in rat pancreatic acinar cells and compared with carbachol, a full muscarinic agonist, together with previous results using JMV-180, a partial agonist of CCK-A receptors. Pilocarpine was found to stimulate amylase release from isolated pancreatic acini in a concentration-dependent manner. At a maximal concentration (10 microM), pilocarpine was only capable of stimulating 63% of the secretion stimulated by a maximal concentration of carbachol. Moreover pilocarpine did not induce a decrease in secretion at supramaximal concentrations as does carbachol. In acini loaded with fura-2, superfusion of pilocarpine resulted exclusively in generation of intracellular Ca2+ concentration ([Ca2+]i) oscillations at all concentrations tested (0.3 microM-1 mM), in marked contrast to high concentrations of full agonists, which result in a biphasic sustained increase in [Ca2+]i. In common with low concentrations of other secretagogues that stimulate [Ca2+]i oscillations, pilocarpine at all concentrations was only able to stimulate a very small increase in phosphoinositide (PI) hydrolysis. In acini previously incubated with [3H]inositol, pilocarpine was shown to stimulate PI hydrolysis 27% above basal, compared with 872% for carbachol. To ascertain if this small degree of PI hydrolysis seen with pilocarpine is responsible for the generation of [Ca2+]i oscillations, an inhibitor of phospholipase C-linked processes, U-73122, which has been shown to inhibit Ca2+ oscillations induced by carbachol and CCK but not JMV-180 was tested. This agent rapidly inhibited pilocarpine-stimulated oscillations, indicating that in contrast to JMV-180, oscillations induced by pilocarpine are the result of PI hydrolysis.

scholarly journals Cyclooxygenase-2 Glycosylation Is Affected by Peroxynitrite in Endothelial Cells: Impact on Enzyme Activity and Degradation

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 496
Author(s):  
Sonia Eligini ◽  
Susanna Colli ◽  
Aida Habib ◽  
Giancarlo Aldini ◽  
Alessandra Altomare ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Cyclooxygenase 2 ◽  
Nitric Oxide Donors ◽  
Metabolic Labeling ◽  
Dependent Manner ◽  
De Novo Synthesis ◽  
Human Endothelial Cells ◽  
Prolonged Incubation ◽  
Cox 2

The exposure of human endothelial cells to 3-morpholinosydnonimine (SIN-1) induced the expression of cyclooxygenase-2 (COX-2) in a dose- and time-dependent manner. Interestingly, after a prolonged incubation (>8 h) several proteoforms were visualized by Western blot, corresponding to different states of glycosylation of the protein. This effect was specific for SIN-1 that generates peroxynitrite and it was not detected with other nitric oxide-donors. Metabolic labeling experiments using 35S or cycloheximide suggested that the formation of hypoglycosylated COX-2 was dependent on de novo synthesis of the protein rather than the deglycosylation of the native protein. Moreover, SIN-1 reduced the activity of the hexokinase, the enzyme responsible for the first step of glycolysis. The hypoglycosylated COX-2 induced by SIN-1 showed a reduced capacity to generate prostaglandins and the activity was only partially recovered after immunoprecipitation. Finally, hypoglycosylated COX-2 showed a more rapid rate of degradation compared to COX-2 induced by IL-1α and an alteration in the localization with an accumulation mainly detected in the nuclear membrane. Our results have important implication to understand the effect of peroxynitrite on COX-2 expression and activity, and they may help to identify new pharmacological tools direct to increase COX-2 degradation or to inhibit its activity.

scholarly journals SYNTHESIS AND MIGRATION OF PROTEINS IN THE CELLS OF THE EXOCRINE PANCREAS AS REVEALED BY SPECIFIC ACTIVITY DETERMINATION FROM RADIOAUTOGRAPHS

1963 ◽  
Vol 16 (1) ◽  
pp. 1-23 ◽  
Author(s):  
H. Warshawsky ◽  
C. P. Leblond ◽  
B. Droz
Keyword(s):  
Specific Activity ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
The Mean ◽  
And Migration ◽  
Rats And Mice ◽  
Silver Grains ◽  
Golgi Zone

Radioautographs of pancreatic acinar cells were prepared in rats and mice sacrificed at various times after injection of leucine-, glycine-, or methionine-H3. Measurements of radioactivity concentration (number of silver grains per unit area) and relative protein concentration (by microspectrophotometry of Millon-treated sections) yielded the mean specific activity of proteins in various regions of the acinar cells. The 2 to 5 minute radioautographs as well as the specific activity time curves demonstrate protein synthesis in ergastoplasm. From there, most newly synthesized proteins migrate to and accumulate in the Golgi zone. Then they spread to the whole zymogen region and, finally, enter the excretory ducts. An attempt at estimating turnover times indicated that two classes of proteins are synthesized in the ergastoplasm: "sedentary" with a slow turnover (62.5 hours) and "exportable" with rapid turnover (4.7 minutes). It is estimated that the exportable proteins spend approximately 11.7 minutes in the Golgi zone where they are built up into zymogen granules, and thereafter 36.0 minutes as fully formed zymogen granules, before they are released outside the acinar cell as pancreatic secretion. The mean life span of a zymogen granule in the cell is estimated to be 47.7 minutes.

Endothelium and mechanical responses of isolated monkey pulmonary veins to histamine

1990 ◽  
Vol 259 (4) ◽  
pp. H1032-H1037 ◽  
Author(s):  
T. Matsuki ◽  
T. Ohhashi
Keyword(s):  
Pulmonary Veins ◽  
Dependent Manner ◽  
High Concentration ◽  
Concentration Dependent Manner ◽  
Mechanical Responses ◽  
Relaxing Factor ◽  
Prostaglandin F2 Alpha ◽  
H2 Receptors ◽  
Endothelium Derived Relaxing Factor ◽  
Stimulation Of

Ring strips of monkey pulmonary veins precontracted with a high concentration of prostaglandin F2 alpha (PGF2 alpha) relaxed in a concentration-dependent manner in response to histamine. Treatment with mepyramine and/or famotidine attenuated the relaxation. 2-Pyridylethylamine (2PEA) and dimaprit caused relaxations in the precontracted preparations, which were inhibited by pretreatment with mepyramine and famotidine, respectively. Removal of endothelium reversed the histamine- and 2PEA-induced relaxations to dose-related contractions. On the other hand, the removal had no effect on the dimaprit-induced relaxations, which were significantly reduced by pretreatment with famotidine. Histamine-induced relaxations in the precontracted strips with endothelium in the presence and absence of famotidine were suppressed or abolished by treatment with methylene blue or hemoglobin but were unaffected by aspirin. It may be concluded that histamine-induced relaxation in monkey pulmonary veins precontracted with PGF2 alpha is mediated by H2-receptors in smooth muscle and H1-receptors in endothelium. Also, stimulation of the endothelial H1-receptors liberates an endothelium-derived relaxing factor.

scholarly journals Zymogen granules of mouse parotid acinar cells are acidified in situ in an ATP-dependent manner

1988 ◽  
Vol 253 (1) ◽  
pp. 267-269 ◽  
Author(s):  
Robert C. De Lisle ◽  
Robin Steinberg ◽  
John A. Williams
Keyword(s):  
Acinar Cells ◽  
Dependent Manner ◽  
Zymogen Granules ◽  
Parotid Acinar Cells
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