Summary. The aim of the present work was to study the effect of a modification of diet composition upon the plasma levels of some peptides known to be involved in the hormonal regulation of exocrine pancreas secretion. Six growing Large-White pigs weighing 41 ± 3.2 kg were fitted with a catheter in a carotid artery ; four ot these pigs were also fitted with permanent fistulae in the pancreatic duct and duodenum. All the pigs were adapted to a control diet (C) during an 8-day period before surgery. In the 8-day postoperative period and a first experimental period of 4 days, they were fed on the same control diet. Three pigs were then fed the experimental diets in the following sequence :fat-rich diet (F) for 7 days, control diet (C) for 7 days, starch-rich diet (S) for 7 days, whereas the other three pigs were fed the same diets over the same time lengths but in inverse sequence : diet S, diet C, diet F. The three diets were isoproteinic (16 % protein) I and isocaloric (3 850 cal/kg). The pancreatic secretion and the plasma levels of cholecystokinin (CCK), secretin, pancreatic polypeptide (PP) and somatostatin were analysed during the 4 days of the first experimental period and the last day of each of the other three experimental periods. Total proteins and lipase and amylase activities were determined in pancreatic juice samples collected over the 7 hours following the morning

Summary. The aim of this work was to investigate the effects on bile secretion of flow rate and site of reinfusion of the collected bile to the animal. Thirty-two pigs weighing 50 ± 3 kg at the beginning of the experiment were fitted with a reentrant fistula in the lower common bile duct and in the upper duodenum. Bile collected from the bile duct was reinfused in four different ways (four groups of 8 animals each) : into the duodenum or the lower common bile duct at a constant flow rate using a peristaltic pump, or into the duodenum or the lower common bile duct at a rate mimicking the flow rate of the secretion using an automatic apparatus.Reinfusing the bile into the lower common bile duct at a rate mimicking the secretion rate provided a daily bile acid production about 21 % higher than the level recorded with the other three methods. This was mainly due to a higher bile acid concentration since the bile flow was only slightly affected by the treatment.Introduction.

Summary. The aim of the present study was to investigate the short-term (8-day) effects of feeding a raw soybean diet on exocrine pancreatic secretion and the plasma levels of gastrointestinal hormones in pigs. After adaptation to a heated soybean diet, 6 pigs (36.5 + 0.8 kg) were fitted with permanent fistulae of the pancreatic duct, the duodenum and a carotid artery. After post-surgical recovery of 8 days, the animals were submitted to two experimental periods, a 4-day period during which they were fed the heated soybean diet and an 8-day period during which they received the raw soybean diet. Exocrine pancreatic secretion and plasma levels of secretin, cholecystokinin, VIP, PP, somatostatin and gastrin were monitored each day of the two experimental periods.On the first day of raw soybean ingestion and till its end, the daily volume of pancreatic juice was higher than the mean volume measured during heated soybean ingestion. On the contrary, daily total protein output was unchanged. Specific activies of chymotrypsin, amylase and lipase were not modified by the raw soybean diet whereas, from the third day of the experimental period, that of trypsin was higher than the corresponding mean value determined during the first experimental period. Plasma levels of secretin and VIP were higher throughout raw soybean ingestion than the corresponding mean levels determined during the first experimental period. The plasma level of cholecystokinin increased only slightly and in the first days of the second experimental period only. The other gastrointestinal hormones studied were slightly (gastrin) or not (somatostatin, PP) affected by raw soybean feeding.It is suggested that feedback control of exocrine pancreatic secretion in pigs was the mechanism involved in the increase of pancreatic juice observed when raw soybean was fed. This volume increase would result from secretin release into the blood.Introduction.

Summary. Regulation of pancreatic secretion in the pig by negative feedback and plasma gastrointestinal hormones. Introduction.

Summary. The aim of the present study in the pig was to describe the biliary and pancreatic secretory component of the migrating myoelectric complex (MMC) during the interdigestive period and after feeding, and to examine the effects of the extracorporal diversion of biliary or pancreatic secretions on the MMC and on the cyclical variation of intraduodenal pH.In a first trial six pigs (50.6 ± 1 .6 kg) were fitted with a permanent catheter in the common bile duct (3 pigs) or in the pancreatic duct (3 pigs) to control the flow of these secretions. They also had a duodenal catheter to return the secretions, and antral and duodenal electrodes for simultaneous recording of motility in fasting conditions. In a second trial ten pigs (50.8 ± 1.5 kg) underwent a similar surgical preparation (5 bile duct and 5 pancreatic duct fistulations). It is concluded that a true biliary and pancreatic secretory component of MMC exists in the pig, and that these 2 secretions strongly contribute to the neutralization of the duodenal contents. However, the major determinant of the cyclical variation of the intraduodenal pH appears to be the periodicity of the acid gastric outflow.Introduction.