Myoelectric activity during small bowel allograft rejection

The effect of rejection on myoelectric activity of an orthotopically transplanted small intestinal segment (group I,N=14) was studied. Electrodes were placed on grafts and recipient small bowel. Isografts (group II,N=5) and native bowel (group III,N=5) served as controls. The first morphological signs of rejection were seen on day 6 and steadily progressed until day 11, when the cellular infiltrate involved all layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable between grafts (group I: 31.9±1.65; group II: 31.36±0.7) and native bowel after transection (group I: 32.16±1.78; group II: 31.50±1.01), which was different (P=0.0001) from intact bowel of group III animals (38.4±0.81). Irregular MMCs were detectable in grafts from day 5 on and replaced after food intake by random spiking activities. At day 8, spiking activities disappeared in allografts, which showed a still preserved mucosal architecture, while slow-wave activities continued. These findings demonstrate that intestinal allografts during rejection develop paralysis before mucosal destruction is established, which might be of clinical relevance.