scholarly journals Control of cholecystokinin receptor dephosphorylation in pancreatic acinar cells

1993 ◽  
Vol 268 (16) ◽  
pp. 12136-12142
Author(s):  
M.P. Lutz ◽  
D.I. Pinon ◽  
L.K. Gates ◽  
S. Shenolikar ◽  
L.J. Miller
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Cholecystokinin Receptor

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.

scholarly journals Cholecystokinin octapeptide inhibits Ca2+-dependent amylase secretion from permeabilized pancreatic acini by blocking the MgATP-dependent priming of exocytosis

1998 ◽  
Vol 330 (1) ◽  
pp. 329-334 ◽  
Author(s):  
J. Philip PADFIELD ◽  
Ninder PANESAR
Keyword(s):  
Acinar Cells ◽  
Secretory Response ◽  
Pancreatic Acinar Cells ◽  
Amylase Secretion ◽  
Rapid Phase ◽  
Pancreatic Acini ◽  
Cholecystokinin Octapeptide ◽  
Cholecystokinin Receptor ◽  
Specific Antagonist

At present little is known about how the low-affinity cholecystokinin receptor inhibits secretagogue-stimulated amylase secretion from pancreatic acinar cells. To examine this question we have determined how cholecystokinin octapeptide (CCK8) influences Ca2+-dependent amylase secretion from α-toxin-permeabilized pancreatic acini. CCK8 significantly inhibited Ca2+-stimulated amylase secretion. The inhibitory actions of CCK8 were completely blocked by the addition of JMV-180, a specific antagonist for the low-affinity CCK8 receptor. Previous studies have shown that Ca2+-dependent amylase secretion from α-toxin-permeabilized acini has two distinct phases [Padfield and Panesar (1997) Am. J. Physiol. 36, G655-660]. There is an initial rapid phase of secretion which represents release from exocytotic sites primed by MgATP prior to permeabilization. This is followed by a slower sustained phase of secretion which, in part, reflects the MgATP-dependent repriming of the exocytotic machinery. CCK8 did not influence the initial rapid phase of the Ca2+-dependent secretory response, but inhibited the second slower sustained phase. Moreover, CCK8 was shown to inhibit the MgATP-dependent priming of exocytosis in the acini. These results indicate that the low-affinity CCK receptor blocks stimulated amylase secretion by inhibiting the MgATP-dependent repriming of exocytosis.

Effect of ethanol on cholecystokinin-stimulated zymogen conversion in pancreatic acinar cells

1996 ◽  
Vol 270 (1) ◽  
pp. G171-G175 ◽  
Author(s):  
M. Katz ◽  
R. Carangelo ◽  
L. J. Miller ◽  
F. Gorelick
Keyword(s):  
Acinar Cell ◽  
Low Dose ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Ethanol Treatment ◽  
Cholecystokinin Receptor ◽  
Cholecystokinin Receptors ◽  
High Doses ◽  
Activation Cascade

Exocrine pancreatic zymogens are proteolytically processed to active forms after they are secreted into the small intestine. However, intracellular conversion of zymogens to active forms can be stimulated by treating pancreatic acinar cells with high doses of cholecystokinin (0.1 microM) or carbamylcholine (0.1 mM). The high doses of cholecystokinin are unlikely to be achieved physiologically. The ability of ethanol to sensitize the acinar cell to zymogen conversion Induced by cholecystokinin or carbamylcholine was examined. Ethanol (10-200 mM) had no effect alone or when combined with carbamylcholine. However, ethanol (25 mM) added with low-dose cholecystokinin (0.1 nM) generated zymogen conversion that was 1) sixfold higher than cholecystokinin alone and 2) equivalent to that generated by highdose cholecystokinin (10 microM). The ability of ethanol to enhance cholecystokinin-induced zymogen conversion was dependent on the dose of ethanol and the duration of ethanol treatment. The cholecystokinin receptor antagonist, L-364,718, blocked the conversion stimulated by the addition of ethanol with cholecystokinin. This effect of ethanol did not change the affinity or number of cholecystokinin receptors, suggesting an effect more distal in the stimulus-activation cascade. These findings demonstrate that ethanol selectively sensitizes the pancreatic acinar cell to cholecystokinin-stimulated zymogen proteolysis.

Reduced cholecystokinin receptor phosphorylation and restored signalling in protein kinase C down-regulated rat pancreatic acinar cells

1998 ◽  
Vol 435 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Rolf L. L. Smeets ◽  
Rammohan V. Rao ◽  
Sjenet E. van Emst-de Vries ◽  
Jan Joep H. H. M. De Pont ◽  
Laurence J. Miller ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Receptor Phosphorylation ◽  
Cholecystokinin Receptor ◽  
Kinase C

Visualization of CCK-evoked exocytic events in rat pancreatic acinar cells

2001 ◽  
Vol 120 (5) ◽  
pp. A24-A24
Author(s):  
H GAISANO ◽  
L TANG ◽  
L SHEU ◽  
W TRIMBLE
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells

Effects of oncogenic K-ras on pancreatic acinar cells In vitro

2001 ◽  
Vol 120 (5) ◽  
pp. A722-A722
Author(s):  
Y BI ◽  
C LOGSDON
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells
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