AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 6 836-G841, Copyright © 1986 by American Physiological Society
Effect of duodenal bile acid delivery on fasting intestinal motor activity
R. B. Scott
Fasting duodenal bile acid delivery is pulsatile and is cyclically
coordinated with the duodenal migrating myoelectric complex (MMC). To
determine whether duodenal bile acid delivery influences the duodenal cycle
period (CP) of the MMC or the intensity of duodenal motor activity, three
dogs were prepared with a duodenal cannula, permitting cannulation of the
common bile duct, duodenal infusion, and manometry. CP was measured with
the enterohepatic circulation intact and after the common bile duct was
cannulated to divert endogenous bile from the duodenum during continuous
duodenal infusion (1.6 ml/min) of 0, 2.5, 12.5, or 25 mM sodium taurocholic
acid in 154 mM NaCl. During a second protocol with the enterohepatic
circulation intact, a control and subsequent CP were measure, and a pulse
(1 ml/min for 10 min) of pooled dog bile (112 mM total bile acids) or 0,
20, 80, or 140 mM sodium taurocholic acid in 154 mM NaCl was infused into
the duodenum at 40% of the second CP (as estimated from control CP). A
motility index was calculated for an interval commencing at 40% of the
control CP and at the start of pulse infusion in the succeeding CP. There
was no significant difference in CP with the enterohepatic circulation
intact compared with that during continuous duodenal infusion of sodium
taurocholic acid. There was no significant change in CP or motility index
after premature pulse infusion of sodium taurocholic acid or pooled dog
bile. Variation in duodenal bile acid delivery did not modulate intensity
of duodenal motor activity or cycling of the MMC.
