AJP - Gastrointestinal and Liver Physiology, Vol 239, Issue 4 311-G318, Copyright © 1980 by American Physiological Society
Longitudinal and circumferential spread of spike bursts in canine jejunum in vivo
N. S. Dusdieker and R. W. Summers
This study demonstrates a new method for quantitatively analyzing
individual intestinal spike bursts and establishes the distribution of
spike burst spread under conditions of fasting and feeding in conscious
healthy dogs. The dimensions and propagation lengths of individual jejunal
spike bursts were determined by studying spike burst spread within
slow-wave cycles. Electromyograms were recorded simultaneously from
multiple closely spaced serosal electrodes in the jejunum (4 equally
distant around the circumference and 16 along the long axis at 3-cm
intervals). At least 75% of the time, spike bursts involved the entire
cross-sectional circumference simultaneously. Greater than 50% of spike
bursts during fasting or feeding spread distally 3-30 cm. The remainder
were isolated or segmental spike bursts involving < 3 cm of jejunum. The
lengths of propagative spike bursts increased with the time during phase II
and reached a maximum of 30-40 cm during phase III. Fed activity showed a
mixture of segmental and longer propagative spike bursts that varied little
with time after feeding. Propagative spike bursts > 3 cm in length
produced at least 85% of the total myoelectric burst activity regardless of
the state of fasting or feeding and constitute the major form of intestinal
motility in the canine jejunum.
