AJP - Gastrointestinal and Liver Physiology, Vol 254, Issue 5 650-G657, Copyright © 1988 by American Physiological Society
Motility of the pyloric sphincter studied by the inductograph method in conscious dogs
H. J. Ehrlein
Institute of Zoophysiology, University of Hohenheim, Stuttgart, Federal Republic of Germany.
The aim of the study is to evaluate the motility of the pyloric sphincter
in conscious dogs by means of extraluminal transducers. For this purpose
induction coils were chronically implanted in 12 dogs. After a meal the
pylorus opened and closed in relation to the gastric waves. The mean
changes in pyloric diameter were 5.4 +/- 1.0 mm. During phase I of the
interdigestive state, the mean degree of pyloric opening was 39 +/- 18%.
Gastric contractions occurring during phase II or phase III were
accompanied with a marked increase in pyloric diameter; the degree of
pyloric opening was 93 +/- 12%. Duodenal instillations of hydrochloric acid
or oleic acid significantly diminished the pyloric diameter. Nutrients
added to a viscous meal also diminished the pyloric opening significantly
in comparison with an acaloric meal. Results suggest that the pyloric
sphincter is involved in the control of gastric emptying. The inductograph
is a useful technique to study pyloric activity without impediment of
luminal flow in animals.
