Cholestyramine augments pancreatic enzyme secretion, gall-bladder contraction, plasma cholecystokinin and pancreatic polypeptide release in response to intraduodenal amino acids

1995 ◽  
Vol 47 (2) ◽  
pp. A13-A14
Author(s):  
P THIMISTER ◽  
A LOUALIDI ◽  
W HOPMAN ◽  
G ROSENBUSCH ◽  
J WILLEMS ◽  
...  
Keyword(s):  
Amino Acids ◽  
Gall Bladder ◽  
Pancreatic Polypeptide ◽  
Pancreatic Enzyme ◽  
Enzyme Secretion ◽  
Bladder Contraction ◽  
Plasma Cholecystokinin ◽  
Pancreatic Enzyme Secretion

Pancreatic polypeptide inhibits pancreatic enzyme secretion via a cholinergic pathway

1987 ◽  
Vol 253 (5) ◽  
pp. G706-G710 ◽  
Author(s):  
G. Jung ◽  
D. S. Louie ◽  
C. Owyang
Keyword(s):  
Pancreatic Polypeptide ◽  
Acetylcholine Release ◽  
Pancreatic Enzyme ◽  
Enzyme Secretion ◽  
Dependent Manner ◽  
Amylase Release ◽  
Opioid Receptor Antagonists ◽  
Cholinergic Pathway ◽  
Pancreatic Enzyme Secretion ◽  
Dose Dependent

In rat pancreatic slices, rat pancreatic polypeptide (PP) or C-terminal hexapeptide of PP [PP-(31-36)] inhibited potassium-stimulated amylase release in a dose-dependent manner. The inhibition was unaffected by addition of hexamethonium but blocked by atropine. In contrast, PP(31-36) did not have any effect on acetylcholine- or cholecystokinin octapeptide-stimulated amylase release. In addition, when pancreatic slices were incubated with [3H] choline, PP(31-36) inhibited the potassium-evoked release of synthesized [3H] acetylcholine in a dose-dependent manner. The inhibitory action of PP was unaffected by adrenergic, dopaminergic, or opioid receptor antagonists. Thus PP inhibits pancreatic enzyme secretion via presynaptic modulation of acetylcholine release. This newly identified pathway provides a novel mechanism for hormonal inhibition of pancreatic enzyme secretion via modulation of the classic neurotransmitter function.

Bovine pancreatic polypeptide as an antagonist of muscarinic cholinergic receptors

1987 ◽  
Vol 252 (3) ◽  
pp. G384-G391
Author(s):  
G. Z. Pan ◽  
L. Lu ◽  
J. M. Qian ◽  
B. G. Xue
Keyword(s):  
Pancreatic Polypeptide ◽  
Pancreatic Enzyme ◽  
Cholinergic Receptors ◽  
Enzyme Secretion ◽  
Amylase Secretion ◽  
Enzyme Release ◽  
Muscarinic Cholinergic Receptors ◽  
Bovine Pancreatic Polypeptide ◽  
Pancreatic Enzyme Secretion ◽  
Muscarinic Cholinergic

In dispersed acini from rat pancreas, it was found that bovine pancreatic polypeptide (BPP) and its C-fragment hexapeptide amide (PP-6), at concentrations of 0.1 and 30 microM, respectively, could significantly inhibit amylase secretion stimulated by carbachol (P less than 0.01 or 0.05, respectively), and this inhibition by BPP was dose dependent. 45Ca outflux induced by carbachol was also inhibited by BPP or PP-6, but they had no effect on cholecystokinin octapeptide- (CCK-8) or A23187-stimulated 45Ca outflux. BPP was also capable of displacing the specific binding of [3H]quinuclidinyl benzilate to its receptors, and it possessed a higher affinity (ki 35 nM) than carbachol (Ki 1.8 microM) in binding with M-receptors. It is concluded from this study that BPP acts as an antagonist of muscarinic cholinergic receptors in rat pancreatic acini. In addition, BPP inhibited the potentiation of amylase secretion caused by the combination of carbachol plus secretin or vasoactive intestinal peptide. This may be a possible explanation of the inhibitory effect of BPP on secretin-induced pancreatic enzyme secretion shown in vivo, since pancreatic enzyme secretion stimulated by secretin under experimental conditions may be the result of potentiation of enzyme release produced by the peptide in combination with a cholinergic stimulant.

Effect of atropine and vagotomy on response of transplanted pancreas.

1979 ◽  
Vol 236 (2) ◽  
pp. E186 ◽  
Author(s):  
T E Solomon ◽  
M I Grossman
Keyword(s):  
Amino Acids ◽  
Protein Secretion ◽  
Sodium Oleate ◽  
Pancreatic Enzyme ◽  
Intestinal Perfusion ◽  
Truncal Vagotomy ◽  
Enzyme Secretion ◽  
Cholinergic Mechanisms ◽  
Pancreatic Enzyme Secretion ◽  
Significant Change

It is well established that atropine and vagotomy inhibit pancreatic enzyme secretion in response to intestinal stimulants such as fat or amino acids. These effects are usually attributed to interference with hypothetical vagal cholinergic mechanisms that facilitate release of cholecystokinin. To determine whether atropine or vagotomy interferes with release of humoral stimulants of pancreatic enzyme secretion, we studied their effect on protein secretion from an autotransplanted portion of pancreas in response to intestinal stimulants in dogs. The transplanted pancreas was as sensitive as the intact pancreas to stimulation by exogenous caerulein, a cholecystokinin-like peptide, and this response was not altered by atropine or vagotomy. Therefore, if vagotomy or atropine interferes with release of humoral pancreatic stimulants, they would be expected to reduce the response of the transplanted pancreas just as they do of the intact pancreas. Truncal vagotomy caused no significant change in protein secretion from the transplant in response to intestinal perfusion with sodium oleate or tryptophan. Atropine was tested only against sodium oleate and caused no change in response. We conclude that release of humoral pancreatic excitants of protein secretion in response to intestinal stimulants is not significantly changed by atropine or vagotomy.

Differences in Insulin, Growth Hormone and Pancreatic Enzyme Secretion after Intravenous and Intraduodenal Administration of Mixed Amino Acids in Man

1973 ◽  
Vol 288 (23) ◽  
pp. 1199-1202 ◽  
Author(s):  
Sotos Raptis ◽  
Hans C. Dollinger ◽  
Karl E. Schröder ◽  
Mark Schleyer ◽  
Gerhard Rothenbuchner ◽  
...  
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Pancreatic Enzyme ◽  
Enzyme Secretion ◽  
Pancreatic Enzyme Secretion ◽  
Intraduodenal Administration

Cholecystokinin mediates feedback regulation of pancreatic enzyme secretion in rats

1986 ◽  
Vol 250 (2) ◽  
pp. G252-G259 ◽  
Author(s):  
D. S. Louie ◽  
D. May ◽  
P. Miller ◽  
C. Owyang
Keyword(s):  
Negative Feedback ◽  
Intravenous Infusion ◽  
Pancreatic Secretion ◽  
Pancreatic Enzyme ◽  
Feedback Regulation ◽  
Enzyme Secretion ◽  
Negative Feedback Regulation ◽  
Plasma Cholecystokinin ◽  
Pancreatic Enzyme Secretion ◽  
Protein Output

Previous studies have shown that trypsin and chymotrypsin in the duodenum exert a negative-feedback regulation on pancreatic enzyme secretion in the rat. The mechanism responsible for this physiological phenomenon is unknown. By use of a specific and sensitive bioassay based on amylase release from isolated pancreatic acini, the role of cholecystokinin in the negative-feedback regulation of exocrine pancreatic secretion was examined. Rats were prepared with duodenal cannulas and pancreaticobiliary cannulas. Diversion of pancreaticobiliary juice resulted in a threefold increase in pancreatic protein output and an increase of plasma cholecystokinin from a basal level of 0.5 +/- 0.08 pM cholecystokinin octapeptide (CCK-8) to 16 +/- 4 pM CCK-8. Perfusion of trypsin (2 mg/h) or pancreaticobiliary juice returned pancreatic protein output to basal levels and plasma cholecystokinin to 2.1 +/- 1.2 and 0.33 +/- 0.1 pM, respectively. The inhibitory effect of trypsin on cholecystokinin release was enzyme and site specific, since inhibition of cholecystokinin release was not observed with perfusion of amylase into the duodenum or with trypsin into the ileum. Intravenous infusion of proglumide abolished the increase in pancreatic secretion following diversion of pancreaticobiliary juice. Intraduodenal perfusion of lidocaine, infusion of tetrodotoxin into the superior mesenteric artery, or intravenous infusion of atropine inhibited the rise in plasma cholecystokinin seen with diversion of pancreaticobiliary juice. These studies suggest that feedback regulation of pancreatic enzyme secretion in the rat is mediated by release of cholecystokinin. Furthermore, the feedback mechanism is neurally mediated, involving a cholinergic pathway.

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