AJP - Gastrointestinal and Liver Physiology, Vol 268, Issue 6 959-G967, Copyright © 1995 by American Physiological Society
Ectopic jejunal pacemakers after jejunal transection and their relationship to transit
J. J. Cullen, J. C. Eagon, F. S. Hould, R. B. Hanson and K. A. Kelly
Department of Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
The hypothesis was that orally moving pacesetter potentials distal to a
site of jejunal transection and anastomosis would slow transit through
jejunum containing them and that reoperation with excision of bowel
containing these pacesetter potentials would restore transit to the
control. In six conscious dogs with jejunal serosal electrodes for
recording myoelectric activity and a jejunal perfusion/aspiration catheter
for measuring transit, jejunal pacesetter potential frequency decreased
distal to a midjejunal transection and anastomosis from 18.7 +/- 0.3 (SE)
cycles/min (cpm) proximal to the site to 14.4 +/- 0.6 cpm distal to the
site (P < 0.05). In addition, orally propagating pacesetter potentials
occurred > 25% of the time in a 37 +/- 7 cm length of bowel distal to
the site during fasting and after feeding. Transit through the segment with
the orally moving pacesetter potentials was slowed during feeding (half
time before and after transection, 7.7 +/- 1.1 and 13 +/- 2.0 min,
respectively, P < 0.05). Resection of the segment with the abnormal
pacesetter potentials shortened the length of bowel containing them to 24
+/- 2 cm (P > 0.05) and restored transit to the control. In conclusion,
orally moving pacesetter potentials distal to a canine jejunal transection
and anastomosis slowed transit through the segment of bowel containing
them. Resection of the segment restored transit to the control.
