The myoelectric activity of ileum in fasted and fed young pigs

To precise the character of myoelectric activity of distal small intestine, in 8 young pigs 1 bipolar electrode was attached at the serosal side of the jejunum and 7 electrodes were sutured at terminal ileum. After the recovery, the animals were fed twice daily during at least 2 weeks and were fasted 24 h before each experiment. Myoelectric activity was recorded with electroencephalograph throughout the experiment lasting 3-5 h. After control recording the standard food was given during the end of ileal phase 1 of migrating myoelectric complex (MMC) and registration of myoelectric activity was continued. Ileal propagated or non-propagated minute rhythm was observed in 64% of the experiments performed, during phase 2b of MMC. In most animals studied, the long isolated spike burst series lasting 1-6 min and short isolated spike burst series lasting 15-25 s were observed. Feeding induced myoelectric activity in the jejunum usually after 1-2 min and, in the ileum, during most episodes, after 2-9 min, for 4-10 min. During and after feeding, the short-lasting "transient fed pattern" was observed. Mean propagation velocity of phase 3 MMC was 4.4 +/- 0.8 and 8.1 +/- 0.6 cm/min (mean +/- S.E.M., p > 0.05) before and after feeding, respectively. Phase 3 MMC was preceded by 2-3 spike burst series lasting 40-70 s each before feeding and 1-3 min after feeding. Single propagated spike bursts arrived more frequently after feeding. Two types of minute rhythm, propagated and stationary, were observed. Giant spike bursts, propagated contractions and ultrarapid spike rushes were recorded occasionally. In conclusion, the myoelectric activity of terminal ileum in swine is eventful, exhibits wide range of irregularity and its response to feeding is relatively weak and delayed as compared to the upper small intestine.