AJP - Gastrointestinal and Liver Physiology, Vol 265, Issue 4 619-G627, Copyright © 1993 by American Physiological Society
Migrating spike complex in the small intestine of the fasting cat
W. C. De Vos
Department of Physiology and Biophysics, University of Illinois, Urbana 61801.
This study characterizes the migrating spike complex (MSC) in the small
intestine of the awake fasting cat and compares the MSC with interdigestive
activity in the small intestine of other species. Electrical activity in
each of 12 cats with implanted electrodes showed MSCs, bands of spike
potentials which attenuated slow-wave frequency and amplitude as the MSCs
progressed distally. MSCs occurred at variable frequency with intervals
ranging from < 1 min to > 5 h and averaged 51.2 +/- 2.8 (SE) min.
MSCs migrated at 1-8 mm/s, accelerating distally; the duration decreased
distally such that the length of the bowel in a burst (2-3 cm proximally)
was conserved. The MSC was associated with an intense prolonged contraction
of duration similar to that of the MSC. Sometimes the MSCs occurred in
close association, and when an MSC period was < 5.7 min, the second MSC
propagated at a slower rate than the first. Frequently, a brief series of
slow wave-associated spikes preceded an MSC. MSCs were not associated with
slow waves. The MSC differs in several respects from the migrating
myoelectric complex of other laboratory animals and is more appropriately
classified in a category that includes giant migrating spikes, prolonged
propagated contractions, power contractions, and migrating action potential
complexes.
