Three-day enteral exposure to a red kidney bean lectin preparation enhances the pancreatic response to CCK stimulation in suckling pigs.

BACKGROUND: A reason for the digestive problems that often occur around early weaning in piglets could be that the pancreas is not yet fully developed and the enzymes required for degradation of the solid food are not secreted in enough amounts. OBJECTIVES: The aim of the study was to investigate the possibility of inducing pancreas maturation with enhanced enzyme secretion. METHODS: 10-day-old suckling pigs were gavage fed with a red kidney bean lectin preparation for 3 days, and the pancreatic response to intravenous infusion of CCK-33 was measured in the anaesthetized animals fitted with pancreatic duct catheters. RESULTS: The pancreatic fluid secretion, protein output, and the trypsin and amylase outputs were significantly increased in response to CCK stimulation after the lectin treatment, as compared to those of the control littermates (p < or = 0.05). In addition, the plasma insulin basal levels and those observed during CCK-33 stimulation were lower in the lectin-treated piglets. CONCLUSION: The results suggested that the lectin treatment led to an increase in the capacity for pancreatic enzyme secretion in the suckling piglets. An enhanced pancreatic function might help to ameliorate the problems that may appear in modern pig production which are associated with weaning.

CCK-B receptor antagonist YF476 inhibits pancreatic enzyme secretion at a duodenal level in pigs.

BACKGROUND: To evaluate the mechanisms by which cholecystokinin (CCK) regulates the exocrine pancreas, the role and location of CCK receptors in the pig were investigated using the CCK-B receptor antagonist YF476 and different administration routes of CCK. METHODS: In 11 anaesthetized pigs, catheters were surgically implanted in the pancreatic duct for juice collection, and in the gastric arteries and jugular vein, so that infusions of CCK-33 could be directed to the duodenal/gastric, duodenal/pancreatic or general circulations, respectively. Experiments were performed under control conditions, and after pretreatment by gavage feeding with YF476, using either a single, low dose of 0.3 micromol kg, which would block the CCK-B receptors, or a 1000 times higher dose (300 micromol kg), which would also block the CCK-A receptors. RESULTS: The increase in the pancreatic output of protein and the enzymes trypsin and amylase observed after the infusion of CCK-33 at 13 pmol kg to the duodenum/stomach or duodenum/pancreas was inhibited by pretreatment with YF476 at both dosages. In contrast, the increase in protein and enzyme output after the infusion of a supraphysiological dose of CCK-33 (130 pmol kg) to the general circulation was not affected by pretreatment with low dosage YF476, whereas high dosage YF476 completely inhibited the stimulated secretion. CONCLUSIONS: These data indicate that CCK-33 given locally to the duodenum in doses raising CCK to physiological plasma levels stimulates the pancreatic enzyme secretion via duodenal CCK-B receptors. Supra-physiological doses of CCK-33 to the general circulation appeared to affect the pancreatic enzyme secretion via CCK-A receptors located elsewhere than in the pancreatic and duodenal tissue.

CCK regulates pancreatic enzyme secretion via short duodenal-pancreatic reflexes in pigs.

BACKGROUND: Different routes of administration of CCK-33 and blockage of CCK-A and muscarinic (m3) receptors are used in this study to evaluate the mechanisms by which cholecystokinin can stimulate the exocrine pancreas. METHODS: The experiment was performed on eight anaesthetized pigs during control conditions and after administration of the CCK-A and m3 receptor antagonists, Tarazepide and 4-DAMP, respectively. Catheters were surgically implanted in the pancreatic duct for juice collection and in the gastric and right gastro-epipoic arteries and in the jugular vein, so that infusions of CCK-33 could be made exclusively to the duodenum/stomach, duodenum/pancreas or general circulation, respectively. RESULTS: Infusion of a low dose of CCK-33 (13 pmol kg(-1)) to the general circulation did not affect pancreatic protein or trypsin output. When the same dose was given directly to the duodenum/stomach or the duodenum/pancreas, pancreatic output increased during both control conditions and after Tarazepide and/or 4-DAMP treatment, though the increase in trypsin output was lower after Tarazepide and/or 4-DAMP blockade. A high dose of CCK-33 (130 pmol kg(-1)) given peripherally stimulated the pancreatic secretion, but this response was totally abolished in Tarazepide and 4-Damp treated animals. CONCLUSIONS: Pancreatic enzyme secretion due to CCK-33 stimulation depends on the presence of short duodenal-pancreatic peptidergic reflexes evoked mainly via low sensitive, probably CCK-B, receptors located in the duodenum/stomach. Pancreatic secretion evoked by peripheral CCK-33 in pharmacological doses was independent of m3 receptors blockade but depended on CCK-A receptors located elsewhere than in the duodenum/pancreas.

Influence of intraduodenally infused olive and coconut oil on postprandial exocrine pancreatic secretions of growing pigs.

The effect of dietary vegetable oils differing in fatty acid composition that were infused directly into the duodenum on exocrine pancreatic secretions in pigs has not previously been studied. The objective of the present study was to determine the acute response of the exocrine pancreas to vegetable oils with various fatty acid profiles under prandial conditions. Six growing pigs (BW 13.2 kg) were surgically prepared with pancreatic duct catheters and duodenal reentrant T-cannulas. The animals were fed twice a day (1000 and 1600) a commercial weaner diet at a rate of 2% of BW. Beginning with the morning feeding, olive oil, coconut oil, or saline as a control were infused in boluses every 5 min in total 0.1% of BW over a period of 1 h directly into the duodenum according to a 3 x 3 Latin square design. Pancreatic juice was collected over a period of 4 h, beginning 1 h preprandially (0900) until 3 h postprandially (1300). A time effect was observed after the infusion of olive oil on the volume of secretion, on protein contents and outputs, as well as on lipase contents and outputs and on colipase contents. The infusion of saline and coconut oil changed the runs of the curves for lipase and colipase outputs. No time x treatment interactions were observed regarding volume of secretion, protein contents and outputs, trypsin contents and outputs, and lipase outputs. The runs of the curves for lipase contents were different between the olive oil and saline treatment and between the olive oil and coconut oil treatment. The runs of the curves for the olive oil and saline treatment differed from each other regarding colipase contents. Pooled values of colipase outputs were elevated after coconut oil treatment, and a positive correlation between trypsin and colipase contents was found. Under prandial conditions, the exocrine pancreas responds differently in its acute secretion to different vegetable oils due to the differences in the fatty acid profiles.