[Effect of physiological stimuli on Oddi's sphincter motility]

The myoelectric activity of the sphincter of Oddi was studied both in the fasted and fed states and following administration of gastrointestinal hormones. Electromyographic recordings were obtained from 21 opossums in the fasted state and following administration of 20 Cal/kg of fat, protein, carbohydrate or isocaloric mixture of these three aliments. The proximal segment of the sphincter of Oddi generated spontaneous spike potentials that migrated to the distal segment of the sphincter. The frequency of spike potentials correlated with the migrating myoelectric complex in the duodenum. Following feeding, the migrating myoelectric complex was abolished and substituted by a fed pattern. The duration of the fed pattern and the frequency of spike potentials depended on the kind of aliment. Cholecystokinin and pentagastrin increased and glucagon and secretion decreased the frequency of spike potentials in the sphincter of Oddi. It is concluded from these studies that the sphincter of Oddi may play an important role in controlling the time and rate of biliary drainage into the duodenum.

Effects of gastrointestinal hormones on Oddi's sphincter and duodenal myoelectric activity and pancreatobiliary pressure. Studies in the opossum

Myoelectric activity of Oddi's sphincter and duodenum was correlated with common duct and pancreatic duct pressures in conscious opossums after infusion of the following substances: cholecystokinin, pentagastrin, glucagon, secretin, and acetylcholine. Cholecystokinin and pentagastrin increased and glucagon and secretin decreased the frequency of spike potentials in Oddi's sphincter and the duodenum. Acetylcholine was associated with the largest increase in spike potentials in both Oddi's sphincter and the duodenum. Although there was variation in the number of pressure elevations related to Oddi's sphincter spike potentials, the baseline pressure remained constant during administration of the hormones. Acetylcholine infusion increased the biliary and pancreatic pressures to 29 and 31 mm Hg, respectively. We conclude that gastrointestinal hormones may have an important role in regulating the excretion of bile and pancreatic juice into the duodenum.

Experimental evaluation of gastric banding for treatment of morbid obesity in pigs

The effectiveness and complications of gastric banding were evaluated in 15 miniature pigs. A Gore-tex or Dacron graft was employed to encircle the stomach. The animals were divided into five groups, three pigs in each group. Group 1 had a 13 mm pouch stoma with a Gore-tex band, Group 2 had a 16 mm pouch stoma with a Gore-tex band, Group 3 had a 13 mm pouch stoma with a Dacron band, Group 4 had a 16 mm pouch stoma with a Dacron band, and Group 5 had a sham operation. The weight variation in the control group was significantly higher than that in the other groups at the ninth postoperative week (p less than 0.05). There was no significant difference among Groups 1, 2, 3, and 4. The gastric band had migrated distally in seven pigs. It was located in the body of the stomach in four animals and in the pylorus in three. These three pigs died from stenosis of the pylorus. The band had eroded and penetrated all stomach layers in three other animals. There was no difference in the incidence of postoperative complications between the Gore-tex and Dacron band groups. The use of this simple operation in the treatment of the morbidly obese patient should be applied with caution.