AJP - Gastrointestinal and Liver Physiology, Vol 258, Issue 5 738-G744, Copyright © 1990 by American Physiological Society
Propagation velocities and frequencies of contractions along canine small intestine
M. L. Siegle, S. Buhner, M. Schemann, H. R. Schmid and H. J. Ehrlein
Division of Gastrointestinal Physiology, University of Hohenheim, Stuttgart, Federal Republic of Germany.
This study was performed to clarify in detail the behavior of the
propagation velocities and frequencies of contractions along the canine
small intestine. In conscious dogs, duodenal, jejunal, and ileal
contractions were recorded by multiple, closely spaced strain gauges and
analyzed by a computerized method. During both the interdigestive and
postprandial states, the propagation velocity increased from the duodenal
bulb to the distal duodenum and declined aborally within the jejunum,
reaching rather constant values in the ileum. The decrease was steepest in
the proximal part of the jejunum. In contrast to the propagation
velocities, the contraction frequencies were almost constant in the upper
small intestine. In the ileum, the contraction frequencies were markedly
lower than in the upper small intestine, indicating that the aboral
decrease in frequency occurred in the distal parts of the jejunum. We
conclude that both the propagation velocities and the frequencies of
contractions decline aborally in a nonlinear fashion. However, the
nonlinear patterns of the frequency and the propagation velocity gradients
are different.
