Ectopic jejunal pacemakers after jejunal transection and their relationship to transit. Cullen, Joseph J., J. Chris Eagon, Frederic-S. Hould, Russell B. Hanson, Keith A. Kelly. Department of Surgery and the Gastroenterology Research Unit, Mayo Clinic and Mayo Foundation, Rochester, MN 55905.
APStracts 2:0019G, 1995.
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 re-operation 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 mid jejunal transection and anastomosis from a mean+/-SEM of 18.7+/-0.3 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 (T1/2 before transection, 7.7+/-1.1 min; after transection, 13+/-2.0 min, 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.

Received 3 May 1994; accepted in final form 25 January 1995.
APS Manuscript Number G165-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 February 1995.