Canine interdigestive and postprandial gallbladder motility and emptying.

The objectives of this study were to characterize intraluminal gallbladder pressure during fasting and postprandially and to determine the relationships between its intraluminal pressure and emptying. Conscious dogs, with chronic indwelling gallbladder and duodenal catheters to measure pressures and infuse nonabsorbable markers, were used to quantify intraluminal pressures and emptying of gallbladder contents and bile into the duodenum during interdigestive and postprandial periods. During the interdigestive period, a brief rise in intragallbladder pressure followed by the flow of bile and 20% of gallbladder marker into the duodenum occurred only during phase II (a period of irregular duodenal contractility preceded by absent duodenal activity, phase I, and followed by a period of regular duodenal contractility, phase III). We suggest that intragallbladder pressure increased secondary to contraction of the gallbladder against a closed sphincter of Oddi and its decline to base line was accompanied by sphincter relaxation, partial gallbladder emptying, and flow of bile into the duodenum. Postprandially, intragallbladder pressure transiently increased and was followed by an isotonic phase lasting 74 +/- 12 min that ended with the onset of rhythmic large-amplitude pressure elevations that continued for 5.1 +/- 1.6 h. Gallbladder emptying was most rapid during the first 30 min postprandially and was completed by 2 h. Thereafter, large-amplitude gallbladder pressure elevations may prevent gallbladder filling and divert hepatic bile into the duodenum until return of the fasting pattern.