AJP - Gastrointestinal and Liver Physiology, Vol 259, Issue 5 745-G752, Copyright © 1990 by American Physiological Society
Fasting and postprandial hepatic bile flow in unanesthetized opossums
I. Takahashi, M. K. Kern, W. J. Dodds, W. J. Hogan, R. D. Layman and H. V. Ammon
Department of Radiology, Medical College of Wisconsin, Milwaukee 53226.
In conscious opossums, we evaluated the relationship between hepatic bile
flow and the intestinal motor function during fasting as well as after
feeding. In six opossums, bipolar electrodes were implanted from the
gastric antrum to the terminal ileum. After cholecystectomy, the common
duct was ligated, and a catheter was tied into the proximal common duct for
collecting hepatic bile. During subsequent studies, hepatic bile flow was
measured, and bile was returned to the duodenum through an externalized
duodenal catheter. Cyclic increases in bile flow during fasting did not
show a close correlate with the duodenal migratory motor complex (MMC)
cycle. Rather, bile flow showed peak values [0.11 +/- 0.02 (SE) ml/min]
when phase III MMC activity reached the midileum. Hepatic bile flow
correlated closely with the amount of bile acid secreted by the liver. When
the bile acid pool was depleted by diverting bile from the intestine,
hepatic secretion of bile fell to uniformly low values of approximately
0.04 ml/min that did not show cyclic variation. Hepatic bile flow after
feeding increased to a maximal value of 0.12 +/- 0.01 ml/min at 90 min. We
conclude that increases in hepatic bile flow during fasting and after meals
are determined mainly by variations in intestinal motor activity that alter
small bowel transit and thereby affect the enterohepatic circulation of
bile acids.
