AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 5 570-G574, Copyright © 1986 by American Physiological Society
Relationships between duodenal motility and pancreatic secretion in fasted and fed dogs
S. J. Konturek, P. J. Thor, J. Bilski, W. Bielanski and J. Laskiewicz
A relationship between duodenal myoelectric or motor activity and exocrine
pancreatic secretion as well as plasma gut hormone levels has been
investigated in fasted dogs, fed dogs, and dogs that were stimulated with
exogenous gut hormones. Pancreatic secretion showed typical periodicity in
phase with the myoelectric or motor activity of the duodenum. Fasting
pancreatic bicarbonate and protein secretion reached peaks during phase III
of the interdigestive migrating motor complex (MMC) cycle that were
significantly larger than nadir levels occurring during phase I of the
cycle. These fasting bicarbonate and protein peaks reached, respectively,
approximately 9 and 30% of the highest postprandial outputs and 4 and 14%
of the maximal secretory capacity elicited by secretin or CCK. They were
accompanied by a significant rise in plasma motilin, gastrin, and
pancreatic polypeptide (PP), but only exogenous motilin given in
physiological dose induced motility pattern and pancreatic secretion
similar to those observed during phase III. Feeding interrupted both motor
and secretory MMC cycle, increased the pancreatic secretion to
approximately 40-60% of the maximal secretory capacity, and was accompanied
by increments in plasma gastrin, cholecystokinin (CCK), secretin, and PP.
None of these hormones applied alone in physiological dose was capable of
reproducing the postprandial inhibition of MMC cycles. We conclude that the
pancreatic secretion in fasted dogs fluctuates periodically in phase with
duodenal motility, but the phase III peak secretory outputs represent only
minute fractions of the maximal secretory capacity and can therefore be
ignored in regular testing of pancreatic secretion.
