ECTOPIC JEJUNAL PACEMAKERS AFTER JEJUNAL TRANSECTION AND THEIR RELATIONSHIP TO TRANSIT

The hypothesis was that orally moving pacesetter potentials distal to a site of jejunal transection and anastomosis would slow transit throu gh jejunum containing them and that reoperation with excision of bowel containing these pacesetter potentials would restore transit to the c ontrol. In six conscious dogs with jejunal serosal electrodes for reco rding myoelectric activity and a jejunal perfusion/aspiration catheter for measuring transit, jejunal pacesetter potential frequency decreas ed 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 dista l to the site (P < 0.05). In addition, orally propagating pacesetter p otentials occurred > 25% of the time in a 37 +/- 7 cm length of bowel distal to the site during fasting and after feeding. Transit through t he segment with the orally moving pacesetter potentials was slowed dur ing feeding (half time before and after transection, 7.7 +/- 1.1 and 1 3 +/- 2.0 min, respectively, P < 0.05). Resection of the segment with the abnormal pacesetter potentials shortened the length of bowel conta ining them to 24 +/- 2 cm (P > 0.05) and restored transit to the contr ol. In conclusion, orally moving pacesetter potentials distal to a can ine jejunal transection and anastomosis slowed transit through the seg ment of bowel containing them. Resection of the segment restored trans it to the control.