Presynaptic inhibition by serotonin of nerve-mediated secretion of pancreatic amylase

1995 ◽  
Vol 268 (2) ◽  
pp. G339-G345 ◽  
Author(s):  
A. L. Kirchgessner ◽  
M. D. Gershon
Keyword(s):  
Presynaptic Inhibition ◽  
Cholinergic Neurons ◽  
Acinar Cells ◽  
Presynaptic Receptors ◽  
Amylase Secretion ◽  
Pancreatic Amylase ◽  
Inhibitory Receptor ◽  
Cholinergic Nerves ◽  
Positive Identification ◽  
Fos Expression

Enteric cholinergic and serotonergic neurons innervate pancreatic ganglia. Enteropancreatic cholinergic neurons are secretomotor, bu the function of the serotonergic cells is unknown and was investigated. Postganglionic cholinergic nerve-mediated amylase secretion was evoked by veratridine in isolated pancreatic lobules. This concentration-dependent response was inhibited by tetrodotoxin (1.0 microM), atropine (5.0 microM), 5-hydroxytryptamine (5-HT; 5.0 microM), 5-hydroxyindalpine (5-OHIP; 10.0 microM; a 5-HT1P agonist), and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.1 microM), but not by hexamethonium (100.0 microM), 2-methyl-5-HT (10 microM), or 5-carboxyamidotryptamine (10 microM). The effects of 5-HT and 5-OHIP were blocked by the 5-HT1P antagonist N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide (5-HTP-DP; 100.0 microM). Carbachol (5.0 microM)-evoked secretion was not affected by 5-HT or 5-OHIP. Veratridine induced c-fos expression in pancreatic neurons and acinar cells. This expression was inhibited by tetrodotoxin, 5-HT, and 5-OHIP. These observations suggest that the serotonergic enteropancreatic innervation inhibits pancreatic secretion via presynaptic receptors on cholinergic nerves. Although the data are consistent with the hypothesis that the inhibitory receptor is a 5-HT1P site, positive identification awaits further study.

Galanin inhibits caerulein-stimulated pancreatic amylase secretion via cholinergic nerves and insulin

2009 ◽  
Vol 297 (2) ◽  
pp. G333-G339 ◽  
Author(s):  
Savio G. Barreto ◽  
Charmaine M. Woods ◽  
Colin J. Carati ◽  
Ann C. Schloithe ◽  
Surendra R. Jaya ◽  
...  
Keyword(s):  
Islet Cells ◽  
Exocrine Secretion ◽  
Antigen Retrieval ◽  
Amylase Secretion ◽  
Dependent Manner ◽  
Pancreatic Amylase ◽  
Cholinergic Nerves ◽  
Concentration Dependent Manner ◽  
Immunohistochemical Studies

Pancreatic exocrine secretion is affected by galanin, but the mechanisms involved are unclear. We aimed to determine the effect and elucidate the mechanism of action of exogenous galanin on basal and stimulated pancreatic amylase secretion in vitro. The effect of galanin on basal-, carbachol-, and caerulein-stimulated amylase secretion from isolated murine pancreatic lobules was measured. Carbachol and caerulein concentration-response relationships were established. Lobules were coincubated with galanin (10−12 M to 10−7 M), carbachol (10−6 M), or caerulein (10−10 M). Lobules were preincubated with atropine (10−5 M), tetrodotoxin (10−5 M), hexamethonium (10−5 M), or diazoxide (10−7 M and 10−4 M) for 30 min followed by incubation with caerulein (10−10 M) alone or combined with galanin (10−12 M). Amylase secretion was expressed as percent of total lobular amylase. Immunohistochemical studies used the antigen retrieval technique and antisera for galanin receptor (GALR) 1, 2, and 3. Carbachol and caerulein stimulated amylase secretion in a concentration-dependent manner with maximal responses of two- and 1.7-fold over control evoked at 10−6 M and 10−10 M, respectively. Galanin (10−12 M) completely inhibited caerulein-stimulated amylase secretion but had no effect on carbachol-stimulated or basal secretion. Atropine and tetrodotoxin pretreatment abolished the caerulein-stimulated amylase secretion, whereas hexamethonium had no significant effect. Diazoxide significantly reduced caerulein-stimulated amylase secretion by ∼80%. Galanin did not affect caerulein-stimulated amylase secretion in the presence of hexamethonium or diazoxide. Glucose-stimulated amylase secretion was also inhibited by galanin. Immunohistochemistry revealed islet cells labeled for GALR2. These data suggest that galanin may modulate caerulein-stimulated amylase secretion by acting on cholinergic nerves and/or islet cells possibly via GALR2 to regulate insulin release.

scholarly journals Inhibitory effect of high leucine concentration on α-amylase secretion by pancreatic acinar cells: possible key factor of proteasome

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Long Guo ◽  
Baolong Liu ◽  
Chen Zheng ◽  
Hanxun Bai ◽  
Hao Ren ◽  
...  
Keyword(s):  
Amylase Activity ◽  
Acinar Cells ◽  
Inhibitory Effect ◽  
Proteasome Activity ◽  
Pancreatic Acinar Cells ◽  
Amylase Secretion ◽  
High Concentration ◽  
Amylase Release ◽  
Cholecystokinin Receptor ◽  
Key Factor

The present study aimed to investigate whether leucine affects the pancreatic exocrine by controlling the antisecretory factor (AF) and cholecystokinin receptor (CCKR) expression as well as the proteasome activity in pancreatic acinar cells of dairy calves. The pancreatic acinar cells were isolated from newborn Holstein bull calves and cultured using the Dulbecco’s modified Eagle’s medium/nutrient mixture F12 Ham’s liquid (DMEM/F12). There were six treatments of leucine dosage including 0 (control), 0.23, 0.45, 1.35, 4.05, and 12.15 mM, respectively. After culture for 3 h, the samples were collected for subsequent analysis. As the leucine concentration increased from 0 to 1.35 mM, the α-amylase activity in media decreased significantly (P<0.05), while further increase in leucine concentration did not show any decrease in α-amylase activity. Addition of leucine inhibited (P<0.05) the expression of AF and CCKR, and decreased the activity of proteasome (P<0.05) by 76%, 63%, 24%, 7%, and 9%, respectively. Correlation analysis results showed α-amylase secretion was negatively correlated with leucine concentration (P<0.01), and positively correlated with proteasome activity (P<0.01) and the expression of CCK1R (P<0.01) and AF (P<0.05). The biggest regression coefficient was showed between α-amylase activity and proteasome (0.7699, P<0.001). After inhibition of proteasome by MG-132, low dosage leucine decreased (P<0.05) the activity of proteasome and α-amylase, as well as the expression of CCK1R. In conclusion, we demonstrated that the high-concentration leucine induced decrease in α-amylase release was mainly by decreasing proteasome activity.

Regulation of CCK-induced amylase release by PKC-δ in rat pancreatic acinar cells

2004 ◽  
Vol 287 (4) ◽  
pp. G764-G771 ◽  
Author(s):  
Chenwei Li ◽  
Xuequn Chen ◽  
John A. Williams
Keyword(s):  
Acinar Cells ◽  
Adenoviral Vectors ◽  
Dominant Negative ◽  
Pancreatic Acinar Cells ◽  
Amylase Secretion ◽  
Wild Type ◽  
Amylase Release ◽  
Pkc Isoforms ◽  
Chemical Inhibitors ◽  
Dominant Negative Variant

PKC is known to be activated by pancreatic secretagogues such as CCK and carbachol and to participate along with calcium in amylase release. Four PKC isoforms, α, δ, ε, and ζ, have been identified in acinar cells, but which isoforms participate in amylase release are unknown. To identify the responsible isoforms, we used translocation assays, chemical inhibitors, and overexpression of individual isoforms and their dominant-negative variants by means of adenoviral vectors. CCK stimulation caused translocation of PKC-α, -δ, and -ε, but not -ζ from soluble to membrane fraction. CCK-induced amylase release was inhibited ∼30% by GF109203X, a broad spectrum PKC inhibitor, and by rottlerin, a PKC-δ inhibitor, but not by Gö6976, a PKC-α inhibitor, at concentrations from 1 to 5 μM. Neither overexpression of wild-type or dominant-negative PKC-α affected CCK-induced amylase release. Overexpression of PKC-δ and -ε enhanced amylase release, whereas only dominant-negative PKC-δ inhibited amylase release by 25%. PKC-δ overexpression increased amylase release at all concentrations of CCK, but dominant-negative PKC-δ only inhibited the maximal concentration; both similarly affected carbachol and JMV-180-induced amylase release. Overexpression of both PKC-δ and its dominant-negative variant affected the late but not the early phase of amylase release. GF109203X totally blocked the enhancement of amylase release by PKC-δ but had no further effect in the presence of dominant-negative PKC-δ. These results indicate that PKC-δ is the PKC isoform involved with amylase secretion.

The effects of kynurenine on pancreatic amylase secretion in the rats

Pancreatology ◽  
2012 ◽  
Vol 12 (6) ◽  
pp. 509
Author(s):  
K. Nawrot-Porąbka ◽  
A. Leja-Szpak ◽  
J. Jaworek
Keyword(s):  
Amylase Secretion ◽  
Pancreatic Amylase

Peripheral CRF activates myenteric neurons in the proximal colon through CRF1 receptor in conscious rats

2002 ◽  
Vol 282 (5) ◽  
pp. G857-G865 ◽  
Author(s):  
Marcel Miampamba ◽  
Celine Maillot ◽  
Mulugeta Million ◽  
Yvette Taché
Keyword(s):  
Protein Gene ◽  
Cell Activity ◽  
Cholinergic Neurons ◽  
Proximal Colon ◽  
Double Labeling ◽  
Spike Burst ◽  
Conscious Rats ◽  
Protein Gene Product ◽  
Neuronal Identity ◽  
Fos Expression

Corticotropin-releasing factor (CRF) injected peripherally induces clustered spike-burst activity in the proximal colon through CRF1 receptors in rats. We investigated the effect of intraperitoneal CRF on proximal colon ganglionic myenteric cell activity in conscious rats using Fos immunohistochemistry on the colonic longitudinal muscle/myenteric plexus whole mount preparation. In vehicle-pretreated rats, there were only a few Fos immunoreactive (IR) cells per ganglion (1.2 ± 0.6). CRF (10 μg/kg ip) induced Fos expression in 19.6 ± 2.1 cells/ganglion. The CRF1/CRF2 antagonist astressin (33 μg/kg ip) and the selective CRF1 antagonist CP-154,526 (20 mg/kg sc) prevented intraperitoneal CRF-induced Fos expression in the proximal colon (number of Fos-IR cells/ganglion: 2.7 ± 1.2 and 1.0 ± 1.0, respectively), whereas atropine (1 mg/kg sc) had no effect. Double labeling of Fos with protein gene product 9.5 revealed the neuronal identity of activated cells that were encircled by varicose fibers immunoreactive to vesicular acetylcholine transporter. Fos immunoreactivity was mainly present in choline acetyltransferase-IR nerve cell bodies but not in the NADPH-diaphorase-positive cells. These results indicate that peripheral CRF activates myenteric cholinergic neurons in the proximal colon through CRF1 receptor.

Evidence for nitroxidergic innervation in monkey ophthalmic arteries in vivo and in vitro

2000 ◽  
Vol 279 (4) ◽  
pp. H2006-H2012 ◽  
Author(s):  
Kazuhide Ayajiki ◽  
Toshiki Tanaka ◽  
Tomio Okamura ◽  
Noboru Toda
Keyword(s):  
Ophthalmic Artery ◽  
Cholinergic Neurons ◽  
Geniculate Ganglion ◽  
Cholinergic Nerves ◽  
Neurogenic Vasodilatation ◽  
Pterygopalatine Ganglion ◽  
The Brain ◽  
Ophthalmic Arteries

In anesthetized monkeys, electrical stimulation (ES) of the pterygopalatine or geniculate ganglion dilated the ipsilateral ophthalmic artery (OA). The induced vasodilatation was unaffected by phentolamine but potentiated by atropine. Intravenous N G-nitro-l-arginine (l-NNA) abolished the response, which was restored byl-arginine. Hexamethonium-abolished vasodilator responses induced solely by geniculate ganglionic stimulation. Thel-NNA constricted OA; l-arginine reversed the effect. Destruction of the pterygopalatine ganglion constricted the ipsilateral artery. Helical strips of OA isolated under deep anesthesia from monkeys, denuded of endothelium, responded to transmural ES with relaxations, which were abolished by tetrodotoxin and l-NNA but were potentiated by atropine. It is concluded that neurogenic vasodilatation of monkey OA is mediated by nerve-derived nitric oxide (NO), and the nerve is originated from the ipsilateral pterygopalatine ganglion that is innervated by cholinergic neurons from the brain stem via the geniculate ganglion. The OA appears to be dilated by mediation of NO continuously liberated from nerves that receive tonic discharges from the vasomotor center. Acetylcholine liberated from postganglionic cholinergic nerves would impair the release of neurogenic NO.

Rat serum induces a differentiated phenotype in a rat parotid acinar cell line

1998 ◽  
Vol 275 (2) ◽  
pp. G259-G268 ◽  
Author(s):  
Yingting Zhu ◽  
John M. Aletta ◽  
Jiayu Wen ◽  
Xuejun Zhang ◽  
Dennis Higgins ◽  
...  
Keyword(s):  
Primary Culture ◽  
Cell Line ◽  
Acinar Cells ◽  
T Antigen ◽  
Continuous Cell Line ◽  
Enzyme Analysis ◽  
Amylase Secretion ◽  
Rat Serum ◽  
Parotid Acinar Cells ◽  
Rat Parotid

To establish a continuous cell line, freshly prepared rat parotid acinar cells were stably transfected with a plasmid vector containing the SV40 large T antigen. The acinar origin of these cells was confirmed by Western blotting, enzyme analysis, and morphological analysis. Transformed cells grown in 10% rat serum showed a modest reduction in cell number after 7 days and a concentration- and time-dependent increase in amylase levels ∼16 times greater than those observed in fetal bovine serum-treated cells. Ultrastructural analysis revealed that cells grown in rat serum harbored protein-filled secretory granules localized adjacent to the endoplasmic reticulum, and punctate amylase-specific immunofluorescence distributed throughout the cytoplasm was consistent with the presence of amylase in secretory organelles. Clonal cells express tissue-specific proline-rich proteins and the four protein kinase C isozymes present in primary culture. Carbachol and isoproterenol stimulated [3H]protein secretion and isoproterenol enhanced amylase secretion from cells grown in rat serum. Moreover, norepinephrine, carbachol, and substance P produced a time- and concentration-dependent rise in cytoplasmic Ca2+. This continuous cell line of parotid acinar cells, which after treatment with rat serum retains the basic structural and functional properties of primary culture cells, will be utilized as a model system for studying long-term biological processes that regulate parotid cell function.

A primary culture of parotid acinar cells retaining capacity for agonists-induced amylase secretion and generation of new secretory granules

2005 ◽  
Vol 320 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Junko Fujita-Yoshigaki ◽  
Asako Tagashira ◽  
Tomoyoshi Yoshigaki ◽  
Shunsuke Furuyama ◽  
Hiroshi Sugiya
Keyword(s):  
Primary Culture ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Amylase Secretion ◽  
Parotid Acinar Cells

scholarly journals Morphometric Measurements to Quantify the Cerulein Induced Hyperstimulatory Pancreatitis of Rats under the Protective Effect of Lectins

1998 ◽  
Vol 17 (4) ◽  
pp. 219-230 ◽  
Author(s):  
Ludwig Jonas ◽  
Ulrike Mikkat ◽  
Anke Witte ◽  
Uta Beckmann ◽  
Katrin Dölker ◽  
...  
Keyword(s):  
Protective Effect ◽  
Amylase Activity ◽  
Acinar Cells ◽  
Inhibitory Effect ◽  
Pancreatic Acinar Cells ◽  
Amylase Secretion ◽  
Ulex Europaeus ◽  
Serum Amylase Activity

In preceding papers we demonstrated an inhibitory effect of wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA) on the cholecystokinin (CCK) binding to the CCK receptor of rat pancreatic cells and also on the CCK induced Ca2+release and α-amylase secretionin vitroas well as on pancreatic secretion of intact ratsin vivo. In the present study we show the same inhibitory effect of both lectins on the cerulein pancreatitis of rats. This acute pancreatitis was induced by supramaximal injections (5 µg/kg/h iv or 10 µg/kg/h ip) of the CCK analogue cerulein in rats every hour. To monitor the degree of pancreatitis, we measured the number and diameter of injury vacuoles in the pancreatic acinar cells as one of the most important signs of this type of pancreatitis by light microscopic morphometry with two different systems on paraffin sections. Furthermore, the serum α-amylase activity was measured biochemically. We found a correlation between the diameter of vacuoles inside the acinar cells and the serum enzyme activity up to 24 h. The simultaneous ip administration of cerulein and WGA or UEA in a dosage of 125 µg/kg/h for 8 h led to a reduction of vacuolar diameter from 13.1 ± 2.0 µm (cerulein) to 7.5 ± 1.1 µm (cerulein + WGA) or 7.2 ± 1.3 µm (cerulein + UEA). The serum amylase activity was reduced from 63.7 ± 15.8 mmol/l \times min (cerulein) to 37.7 ± 11.8 (cerulein + WGA) or 39.4; +52.9; -31.1 (cerulein + UEA-I). Both parameters allow the grading this special type of pancreatitis to demonstrate the protective effect of the lectins.

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