MYOELECTRIC ACTIVITY DURING SMALL-BOWEL ALLOGRAFT-REJECTION

The effect of rejection on myoelectric activity of an orthotopically t ransplanted small intestinal segment (group I, N = 14) was studied. El ectrodes were placed on grafts and recipient small bowel. Isografts (g roup II, N = 5) and native bowel (group III, N = 5) sewed as controls. The first morphological signs of rejection were seen on day 6 and ste adily progressed until day II, when the cellular infiltrate involved a ll layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable betwee n 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 fro m 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 co ntinued These findings demonstrate that intestinal allografts during r ejection develop paralysis before mucosal destruction is established, which might be of clinical relevance.