AJP - Gastrointestinal and Liver Physiology, Vol 251, Issue 2 201-G207, Copyright © 1986 by American Physiological Society
Generation of phases I and II of migrating myoelectric complex in the dog
I. M. Lang, S. K. Sarna and R. E. Condon
The mechanisms of generation of most of the phases of the migrating
myoelectric complex (MMC) are unclear. Except for phase III activity, this
issue has not been investigated directly. We have qualitatively examined
the relations between different phases of the MMC cycle in order to provide
an objective basis for the formation of theories. Eight dogs of either sex
were implanted with 10 bipolar electrodes distributed along the
gastrointestinal tract. Myoelectric activity was recorded during the fasted
state or after feeding until the return of the MMC cycle. The relations
between phase I duration, phase II duration, phase III migration time, and
phase III period were examined using simple linear-regression methods. We
found that only phase I duration was highly correlated (r = 0.87, P less
than 0.01) with phase III migration time and that only phase II duration
was highly correlated (r = 0.90, P less than 0.01) with phase III period.
In either the fed or fasted state, phase III activity that began in the
midjejunum was accompanied concurrently with phase I activity of the
duodenum and upper jejunum, where phase III activity had not occurred.
Also, the position of phase III activity in the lower small intestine when
phase I activity of the upper small intestine ended was 277 +/- 24 cm (83
+/- 5% of the small intestinal length) from the pylorus, and the
coefficient of variation of this position was significantly smaller (P less
than 0.01) than that of the other cycle variables.(ABSTRACT TRUNCATED AT
250 WORDS)
