No abstract available.
Exocytosis/physiology* ; Pancreas/secretion ; Pancreas/physiology* ; Pancreas/cytology*

AIMTo know the effect of cysteamine on the pancreatic secretion and enzyme activity in geese.

METHODSEight adult geese fitted chronic pancreatic and duodenal cannulas were used to evaluate the effect of cysteamine (CS) on the pancreatic secretion and enzyme activity. The experiment was consist of control and treated phase. CS was added in the diet at the dosage of 100 mg/kg bw on the first day of treated phase. The birds were free fed at daytime (8:00-20:00) and fasted at nighttime (20:00-8:00). The pancreatic juice samples were collected continuously for three days in each phase.

RESULTSCS increased the average rate of pancreatic secretion by 240.16% (P < 0.01), in which that of daytime was elevated by 234.45% (P < 0.01), while that of nighttime elevated by 253.70% (P < 0.01). The secretion volume at daytime was more than that of night. CS increased trypsin activity by 49.05% (P < 0.01), whereas lipase and amylase activity was reduced by 25.44% (P < 0.01) and 21.95% (P < 0.01) separately. The one hour total activity of trypsin, lipase and amylase were elevated by 406.88% (P < 0.01), 153.58% (P < 0.01) and 166.59% (P < 0.01) respectively. Ratios of pancreatic secretion were different between day and night.

CONCLUSIONThese results indicate that CS can affect the pancreatic juice secretion and pancreatic enzyme activity by depleting the somatostatin, so that benefits to improve the digestive foundation and supply more nutrition for quickly growing in geese.

Animals ; Cysteamine ; pharmacology ; Geese ; physiology ; Pancreas ; drug effects ; enzymology ; secretion ; Pancreatic Juice ; secretion ; Pancreatin ; metabolism

BACKGROUNDThe pathogenesis of acute pancreatitis is complex and largely unclear. The aim of this study was to explore the relationship between modes of cell death in pancreatic acinar cells, the release of cell contents and the inflammatory response of macrophages.

METHODSOur experiment included four groups: group A (the control group), group B (AR42J cells overstimulated by caerulein), group C (AR42J cells treated with lipopolysaccharide and caerulein), and group D (AR42J cells treated with octreotide and caerulein). Apoptosis and oncosis, and the release of amylase and lactate dehydrogenase (LDH) from AR42J cells were detected. Rat macrophages were stimulated by 1 ml supernatant of culture medium of AR42J cells. Finally, NF-kappaB activation and TNF-alpha and IL-1beta secretion by macrophages were detected.

RESULTSOncotic cells in group C increased while apoptotic cells decreased (P < 0.05); cells in group D had the inverse reaction. The release of amylase and LDH changed directly with the occurrence of oncosis. The transcription factor NF-kappaB was activated and secretion of TNF-alpha and IL-1beta were significantly higher in group C than in group B (P < 0.05); in group D, these actions were significantly lower than in group B (P < 0.05). This trend was in line with changes in amylase and LDH production.

CONCLUSIONThere is a close relationship between modes of pancreatic acinar cell death, the release of cell contents and the inflammatory reaction of macrophages.

Amylases ; secretion ; Animals ; Apoptosis ; Interleukin-1beta ; secretion ; L-Lactate Dehydrogenase ; secretion ; Macrophage Activation ; Male ; NF-kappa B ; metabolism ; Pancreas ; pathology ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; secretion

Pancreatic polypeptie (PP) is released from the pancreas in response to vagal stimulation. Amongst other effects, PP has been reported to inhibit pancreatic exocrine function. Apart from any potential physiological role, such inhibition could have important consequences for in vitro studies of pancreatic function employing acetylcholine as a stimulus. We have therefore tested the effect of bovine PP on two in vitro pancreatic preparations: the incubated, uncinate pancreas of young rats and the perfused cat pancreas. In the former, PP (10(-10)-10(-8)M) had little or no effect on enzyme discharge or45Ca efflux under basal conditions or during stimulation with caerulein, CCK-PZ or acetylcholine. In the perfused cat pancreas, similar concentrations of PP were also without effect on fluid secretion evoked by secretin infusion, or enzyme discharge evoked by CCK-PZ injection or infusion. We conclude that bovine PP has no direct effects on the cellular mechanisms responsible for pancreatic electrolyte secretion or enzyme discharge in the species studied.
Acetylcholine/pharmacology ; Amylases/secretion* ; Animal ; Caerulein/pharmacology ; Calcium/metabolism* ; Cats ; Cholecystokinin/pharmacology ; Electrolytes/secretion* ; In Vitro ; Pancreas/drug effects ; Pancreas/metabolism* ; Pancreatic Polypeptide/pharmacology* ; Perfusion ; Rats ; Secretin/pharmacology

Twenty dyes which previously have been claimed to be excreted in pancreatic juice were reinvestigated to determine to what extent they could be eliminated through the pancreas. Exogenous secretin or cholecysto-kinin-pancreozymin(CCK-PZ) stimuli were used in dogs which had been given intravenous dye solutions at the rate of 1mg/min. In this experiment among the twenty dyes, only six were found to be eliminated through the pancreas. The intensity of dye color in pancreatic juice was estimated photometrically or macroscopically. The dye color intensity decreased as follows; basic fuchsin, acridine red, new fuchsin, rhodamin B, phenol red and rhodamin 6G. Basic fuchsin consistently appeared in CCK-PZ stimulated juice. However, it was seen in only a scant amount or not at all in juice stimulated by purified Vitrum (Sweden) secretin. Similar findings were observed in cats and conscious pigs. The content of basic fuchsin in pancreatic juice was more related to changes in the enzyme concentration than to other components. The chloride content of the juice was related to the amylase or basic fuchsin secretion. However, the chloride content was inversely related to the secreted volume. Vagal stimulation or the administration of parasympathomimetics produced a juice rich in enzyme content, but the dye response to vagal stimulation was weak. Usually the volume of secreted pancreatic juice following stimulation by Boots (England) secretin is greater than stimulated by purified Vitrum preparation. Basic fuchsin was slightly reduced during its elimination from pancreas or when present in alkaline pancreatic juice. Adding acid and formaldehyde revived the color. The acridine red and other pyronine dyes caused the juice to fluorescence. This effect lasted over 24 hours.
Animal ; Dogs ; Dyes/metabolism* ; Pancreas/metabolism* ; Pancreatic Juice/secretion* ; Rosaniline Dyes/metabolism*

BACKGROUND/AIMS: Pancreatic acini of streptozotocin (STZ)-induced diabetic rats release amylase less than normal acini on cholecystokinin (CCK) stimulation. Pancreatic enzyme secretion has been closely related to the intracellular calcium concentration ([Ca2+]i) of the acinar cell. In the present study, sequential changes of the intracellular calcium signal which probably underlie the altered enzyme secretion in response to CCK-8 were investigated using pancreatic acini from diabetic rats. METHODS: Diabetic rats were prepared by single intravenous injection of STZ (70 mg/kg). Stimulating experiments with CCK-8 were performed 7 days later. Pancreatic acini were isolated by collagenase digestion. Amylase release and [Ca2+]i were measured by colorimethod and calcium imaging, respectively. The geometry of intracellular calcium signal was analyzed. RESULTS: Normal acini exhibited concentration-dependent [Ca2+]i increase and regular oscillatory calcium signal on CCK-8 stimulation. Amylase release was also concentration-dependent. However, diabetic acini showed significantly less [Ca2+]i increase, prolonged time to peak [Ca2+]i, decreased calcium spikes number, and decreased amylase release compared with normal acini. The decreased [Ca2+]i in diabetic acini was restored significantly by insulin treatment. CONCLUSIONS: Relatively decreased amylase release in diabetic pancreatic acini in response to CCK, appears to be associated with altered calcium signal due to insulin deficiency.
Amylases/*secretion ; Animals ; Calcium Signaling/*drug effects ; Diabetes Mellitus, Experimental/*physiopathology ; Pancreas/cytology/metabolism/*secretion ; Rats ; Rats, Sprague-Dawley ; Sincalide/*pharmacology

To determine whether exocrine pancreatic secretion is regulated by endogenous somatostatin, somatostatin deficiency was induced by cysteamine. Rats were subcutaneously administered a single dose of cysteamine (30 mg/100 g body weight) 12 hr before experiment. Anesthetized rats were prepared with cannulation into bile duct, pancreatic duct, duodenum, and jugular vein and pancreatic juice was collected. For in vitro study, isolated pancreata of rats, pretreated with cysteamine, were perfused with an intraarterial infusion of Krebs-Henseleit solution (37 degrees C) at 1.2 mL/min, and pancreatic juice was collected in 15-min samples. In vivo experiment of the rat, the mean basal pancreatic secretions, including volume, bicarbonate, and protein output were significantly increased from 18.4+/-0.5 microL/30 min, 0.58+/-0.05 microEq/30 min, and 214.0+/-26.1 microg/30 min to 51.6+/-3.7 microL/30 min, 1.52+/-0.11 microEq/30 min, and 569.8+/-128.9 microg/30 min, respectively (p<0.05). In the isolated perfused pancreas, cysteamine also resulted in a significant increase in basal pancreatic secretion (p<0.05). Simultaneous intraarterial infusion of octreotide (10 pmol/hr) to isolated pancreata partially reversed the effect of cysteamine on basal pancreatic secretion. These findings suggest that endogenous somatostatin play an important role on the regulation of basal pancreatic exocrine secretion.
Animal ; Cysteamine/pharmacology* ; Hormone Antagonists/pharmacology* ; Hormones, Synthetic/pharmacology ; In Vitro ; Male ; Octreotide/pharmacology ; Pancreas/secretion ; Pancreas/drug effects* ; Perfusion ; Rats ; Rats, Sprague-Dawley ; Somatostatin/antagonists & inhibitors*

In pancreatic acinar cells Ca(2+)-dependent secretagogues promote the fusion of zymogen granules (ZG) with the apical plasma membrane (PM) and exocytosis of digestive enzymes. In addition to exocytotic fusion complexes between SNARE proteins in the ZG membrane (ZGM) and the apical PM, enzyme secretion elicited by Ca(2+)-dependent secretagogues requires cytosolic Cl and K+ and is inhibited by blockers of Cl- and K+-channels. We have identified a Cl-conductance activated by ATP, and a K+-conductance (with properties similar to ATP-sensitive K+-channels), regulated by the granule matrix protein Zg-16p in the ZGM. Both conductances are inversely regulated by a 65-kD mdr1 gene product. We have also identified a novel Ca(2+)-activated anion conductance in ZGM, the Ca(2+)-sensitivity of which increases 50-fold when Cl is replaced by 1. This conductance is blocked by micromolar H2-DIDS or DTT, reminiscent of a family of epithelial Ca(2+)-activated Cl -channels (CaCC). Expression of a CaCC in exocrine pancreas has been confirmed by RT-PCR analysis, and by immunoblotting and immunogold labeling of ZG membranes. These data suggest that ion channels in the ZGM are essential elements in pancreatic exocytosis.
Animal ; Chloride Channels/metabolism* ; Chloride Channels/genetics ; Exocytosis/physiology* ; Gene Expression/physiology ; P-Glycoprotein/metabolism ; P-Glycoprotein/genetics ; Pancreas/secretion* ; Pancreas/cytology ; Potassium Channels/metabolism* ; Potassium Channels/genetics ; Secretory Vesicles/secretion ; Secretory Vesicles/metabolism* ; Support, U.S. Gov't, P.H.S.

To determine the adequate models for studying the functions of pancreatic acinar cells, secretory responses to CCK and to CCK receptor antagonist, L-364, 718 were examined in freshly isolated cells and confluent monolayer cells. The results showed that as CCK concentration increased, releases of amylase and lipase increased dose-dependently reaching a maximum at 10(-9) M in acinar cells cultured in serum-containing media as well as in serum-free media. Acinar response to CCK was partially inhibited by L-364, 718, L-364, 718 itself had no effect on the releases of both amylase and lipase. Confluent monolayer of acinar cells released relatively low levels of enzymes and exhibited less response to CCK. In conclusion, short-term culture of acinar cells would be suitable to study the regulation of pancreatic enzyme secretion, and serum factors do not influence acina response to the secretagogues. However, confluency of the acinar cells resulted in the loss of their secretory potential in the aspect of amylase and lipase release.
Amylases/secretion ; Animal ; Benzodiazepinones/pharmacology ; Cells, Cultured ; Cholecystokinin/*pharmacology ; Devazepide ; Dose-Response Relationship, Drug ; Hormone Antagonists/pharmacology ; Lipase/secretion ; Male ; Pancreas/cytology/*drug effects/*secretion ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholecystokinin/antagonists & inhibitors ; Support, Non-U.S. Gov't

No abstract available.
Amylases/analysis ; Bicarbonates/analysis* ; Chronic Disease ; Endoscopy, Digestive System ; Human ; Pancreas/physiology* ; Pancreatic Juice/secretion ; Pancreatic Juice/enzymology ; Pancreatic Juice/chemistry* ; Pancreatitis/metabolism ; Pancreatitis/diagnosis*