AJP - Gastrointestinal and Liver Physiology, Vol 262, Issue 3 498-G504, Copyright © 1992 by American Physiological Society
A complex avian intestinal motility response to fasting
M. H. Clench and J. R. Mathias
Department of Internal Medicine, School of Medicine, University of Texas Medical Branch, Galveston 77550.
The rhythmic oscillating complex (ROC) is described from a series of
experiments that surveyed the myoelectric activity of the avian small
intestine as recorded from chronically implanted bipolar electrodes. A
highly organized myoelectric event in the fasting avian small intestine,
the ROC is demonstrated in detail in chickens (Gallus); it is also found in
other gallinaceous birds but not in owls (Strix) or mammals. The ROC
comprises rapidly propagating bursts of spike potentials (SPBs) that occur
in a regular and predictable pattern: single orad SPBs alternate with
groups of aborad SPBs. An average ROC in a chicken contains a mean of 78.9
+/- 2.0 (mean +/- SE) SPBs (37% orad, 63% aborad) that rapidly traverse the
full length of the small intestine. The aborad SPBs move at mean velocities
of 25.0 +/- 0.5 cm/s and last a mean of 0.9 +/- 0.0 s at an electrode site;
the orad SPBs are faster (41.2 +/- 2.3 cm/s) and longer in duration (1.3
+/- 0.0 s). ROC activity continues for a mean of 7.6 +/- 0.2 min. ROCs
occur only in a well-fasted gut as often as every 3 h and apparently for as
long as the bird remains without food. Because ROCs restimulate fed-state
activity in the stomach and small intestine, we hypothesize that they
recycle nutritive material for further digestive activity in the distal
tract.
