Differing Effects of Ethanol on in vitro Stimulated Pancreatic Enzyme Secretion in Ethanol-Fed and Control Rats

Pancreas ◽  
1990 ◽  
Vol 5 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Daniel N. Schmidt ◽  
Stephen J. Pandol
1977 ◽  
Vol 55 (3) ◽  
pp. 639-643 ◽  
Author(s):  
J. Morisset ◽  
A. R. Beaudoin

Pancreatic enzyme secretion induced by urecholine or cholecystokinin–pancreozymin (CCK–PZ) is inhibited by tetracaine. If the pancreatic tissue is preincubated with tetracaine then washed out, the subsequent response to CCK–PZ is not affected while that to urecholine is impaired. In contrast with atropine, tetracaine loses its inhibitory potency once secretion has been initiated by urecholine before the addition of the local anaesthetic. Calcium efflux studies have shown that addition of tetracaine in vitro is associated with release of calcium in the incubation medium. This effect on calcium efflux might explain partly the inhibitory action of the drug.


1992 ◽  
Vol 263 (1) ◽  
pp. G102-G107 ◽  
Author(s):  
H. C. Soudah ◽  
Y. Lu ◽  
W. L. Hasler ◽  
C. Owyang

The mechanism by which physiological concentrations of cholecystokinin (CCK) evoke pancreatic exocrine secretion in humans was investigated. CCK octapeptide (CCK-8) dose dependently increased trypsin and lipase output in healthy humans. Atropine inhibited CCK-8 (10 ng.kg-1.h-1)-stimulated trypsin output by 84.0 +/- 7.7% and lipase output by 78.6 +/- 9.2%. The inhibition with atropine was much less with a CCK-8 dose of 40 ng.kg-1.h-1 (41.8 +/- 6.6% for trypsin and 46.3 +/- 7.3% for lipase). CCK-8 at 10 ng.kg-1.h-1 produced plasma CCK levels similar to postprandial levels (6.0 +/- 1.3 vs. 6.9 +/- 0.8 pM), whereas the 40-ng.kg-1.h-1 dose produced supraphysiological levels (18.4 +/- 3.1 pM). To evaluate if CCK might act via stimulation of cholinergic nerves, in vitro studies were performed using rat pancreas. CCK-8 (10 nM-10 microM) stimulated [3H]acetylcholine release from pancreatic lobules that was blocked by tetrodotoxin, a calcium-free medium, and the CCK antagonist L364,718. In conclusion, CCK-stimulated pancreatic enzyme secretion is dependent on cholinergic neural and noncholinergic pathways. In humans, CCK infusions, which produce plasma CCK levels similar to those seen postprandially, stimulate the pancreas predominantly via a pathway dependent on cholinergic innervation. Correlative in vitro experiments suggest that CCK may act by stimulation of neural acetylcholine release. In contrast, supraphysiological CCK infusions act in part via noncholinergic pathways.


1974 ◽  
Vol 52 (2) ◽  
pp. 174-182 ◽  
Author(s):  
A. R. Beaudoin ◽  
C. Marois ◽  
J. Dunnigan ◽  
J. Morisset

Pancreatic amylase secretion was studied using an in vitro system. Secretion was increased by urecholine and cholecystokinin–pancreozymin (CCK–PZ). Addition of tetracaine and dibucaine to the medium abolished secretion stimulated by urecholine and decreased by 75% that stimulated by CCK–PZ. In contrast, an increase in enzyme secretion was observed after dibutyryl cyclic AMP; this was potentiated by tetracaine added to the medium. Oxygen uptake by pieces of pancreatic tissue was not affected by tetracaine. Adenylate cyclase activity, increased in vitro when CCK–PZ was added to a pancreas homogenate, was inhibited by 15% by tetracaine at 2 mM and by 67.5% at the 10 mM concentration.From data known on biochemical reactions associated with the process of secretion and the results described in the present paper, we propose a model for the activation of the pancreatic adenylate cyclase complex. Associated to the depolarization of the acinar cell plasma membrane by urecholine and CCK–PZ and an inward movement of sodium and calcium, there is an immediate rise in adenylate cyclase activity within 10 s which is timed with the initiation of amylase secretion.


1981 ◽  
Vol 240 (2) ◽  
pp. G109-G113
Author(s):  
A. La Bella ◽  
R. G. Lahaie ◽  
H. Sarles ◽  
J. C. Dagorn

Felber et al. (Lancet 2: 185-188, 1974) reported that duodenal extracts obtained from rats fed a given meal induced the specific secretion of related pancreatic enzymes. Such an observation challenges the generally accepted theory of parallel secretion of pancreatic enzymes. Although these experiments were faithfully reproduced, no induction of specific enzyme secretion could be obtained. Moreover, comparison of the secretagogue potency of different preparations of duodenal extract, both in vivo (anesthetized rat) and in vitro (pancreatic lobules), demonstrated that in the original extraction procedure most of the secretagogue activity was lost. Finally, even the fully active extract failed to induce specific enzyme secretion. It is therefore unlikely that duodenal extracts from rats fed a specific meal can induce selective secretion of the related enzyme.


2020 ◽  
Vol 1 (30) ◽  
pp. 30-36
Author(s):  
E. A. Krylova ◽  
D. V. Aleinik

The article presents the results of a study of the effectiveness of the use of an inhibitor of pancreatic enzyme secretion of octreotide (Octrade) for the prevention of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). It was shown that the administration of Octrade at a dose of 0.3 mg in 500 ml of 0.9 % NaCl by continuous intravenous infusion for 7 hours and then 0.1 mg of Octrade subcutaneously at 6 and 12 hours after the end of intravenous infusion significantly reduced the frequency of pancreatitis (4.0 % and 22.2 %; p < 0.05) and hyperamylasemia (8.0 % and 25.9 %; p < 0.05) after ERCP. It is concluded that Octrade is effective in preventing the development of pancreatitis and hyperamilasemia after ERCP.


1987 ◽  
Vol 253 (5) ◽  
pp. G706-G710 ◽  
Author(s):  
G. Jung ◽  
D. S. Louie ◽  
C. Owyang

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.


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