The effects of ischemia and reperfusion on intestinal motility.

The interdigestive migrating motor complex (MMC) has been demonstrated to be a reliable indicator of intestinal motility and function. The effects of low perfusion on the MMC have never been studied. Fourteen newborn Yorkshire piglets (5 to 18 days old, weighing 2.9 +/- 0.4 kg) underwent celiotomy under general anesthesia with placement of four jejunal electrodes (50 cm apart) as well as a superior mesenteric artery (SMA) Doppler flow probe and a pericardial catheter. Group 1 (n = 5) had operation alone. Group 2 (n = 9) had nonocclusive mesenteric ischemia induced by reversible cardiac tamponade for 5 hours between postoperative days 6 to 12. All subjects had MMC phase III electrical activity, cycling time, and propagation velocity recorded daily. In group 2 MMCs were recorded prior to and during ischemia, and during reperfusion. Group 2 animals had 75% +/- 4% decrease in SMA flow during the tamponade period. During the ischemic period, the MMC cycling time (CT) increased from 67 +/- 10 (mean +/- SEM) to 98 +/- 12 minutes (P < .05) and MMC propagation velocity (PV) decreased to 4.2 +/- 2.2 from a baseline value of 10.5 +/- 1.5 cm/min (P < .05). During reperfusion CT and PV values were not significantly different from baseline. The validity of this model is confirmed by the comparable baseline recordings in groups 1 and 2, and by the return of MMC to baseline values within 4 to 7 hours of reperfusion, as seen in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)