AJP - Gastrointestinal and Liver Physiology, Vol 246, Issue 4 426-G432, Copyright © 1984 by American Physiological Society
Canine interdigestive and postprandial gallbladder motility and emptying
O. J. Traynor, R. R. Dozois and E. P. DiMagno
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.
