Alterations of intestinal transit time following ischemia-reperfusion injury in the rat

The influence on intestinal motility in the early stage following intestinal ischemia and reperfusion injury was evaluated by measuring small intestinal transit time in the rat. One milliliter of Krebs-phosphate buffer solution labeled with Na₂⁵¹CrCO₄ was injected directly into the duodenum in order to determine 1 h small intestinal transit time. Delayed small intestinal transit time was seen from 2 h onwards after intestinal ischemia for 20 or 40 min followed by reperfusion. The distribution of the radioactivity demonstrated that most radioactivity was accumulated in the first two segments following intestinal ischemia and reperfusion, which was significantly different from that in rats subjected to sham operation (p < 0.01). Distribution of radioactivity in segments 4 and 5 in the group with reperfusion 6 h after intestinal ischemia for 20 min was significantly higher than that in the group with reperfusion 6 h after intestinal ischemia for 40 min (p < 0.01). These results indicate that delayed intestinal transit may be one of the earliest pathophysiological alterations, associated with time of gut ischemia, and a potential factor in the development of bacterial overgrowth, gut barrier failure and bacterial translocation in hypovolemic conditions.