[Experimental study on intestinal movement after total gastrectomy with jejunal interposition].

In order to study the physiological changes in the intestinal movement after total gastrectomy with jejunal interposition, electromyography was taken from different sites of small intestine of the dogs with and without gastrectomy. Both 6 and 12 months after surgery, the frequency of the basic electric rhythm (BER) of interposed jejunum was lower and that of distal jejunum was much lower than that of duodenum. Most of the interdigestive migrating electric complexes (IMEC) was originated in the oral side of the interposed jejunum; the rate of occurrence increased after the operation further and reached to 91.5% one year after the operation. Most of the dogs showed the propagation pattern from interposed jejunum to duodenum and to distal jejunum; this tendency increased after the operation and 80.8% of the dogs showed this pattern one year after the operation. Thus, the IMEC, conducted usual intestinal order disappeared after the operation and those originated from oral to anal side, regardless of their original order. These results suggest that the order of the propagation of IMEC were determined by the order of the portion of intestine after operation and the parietal continuity, rather than extrinsic nerves, is involved in the propagation. It is also suggested that the propagation of IMEC is not always correlated with the gradient in the difference of the BER between the replaced jejunum and duodenum.

[Effects of buprenorphine on gastrointestinal interdigestive myo-electric complex in dogs].

The effect of buprenorphine on the interdigestive myoelectric complex (IMC) was studied by gastrointestinal electromyogram in 3 mature mongrel dogs. The electromyograms were used to study the IMC cycle and total elapsed time (TET). Buprenorphine had very strong hyperkinetic action on the gastrointestinal tract at doses of 1 and 2 micrograms/kg which revealed phasic contraction, but since this action disappeared when atropine was administered. The phasic contraction originated in the upper jejunum just under the ligament of Treitz and then showed a migration pattern of J-->D and J-->I in 11 out of 23 cases (47.8%), D-->J-->I in nine cases (39.1%), J-->D-->J-->I in one case and no response in two cases. TET (min) showed a mean value of 90.3 +/- 11.2 (n = 23), which was not significantly different from the controls (106.1 +/- 14.3) (n = 24), but tended to be longer (0.1 > p > 0.05). After administration of buprenorphine at a dose of 20 micrograms/kg, phasic contraction migrated to ileum, which was disappeared an interval of 6-7 hours until next IMC. At low doses of buprenorphine were administered after a meal, the postprandial pattern was restored and converted to fasted pattern only one IMC cycle. Buprenorphine is partial agonist for the mu receptor. Ahmad et al. (1989) reported that alpha 2 adrenergic receptor and opiate receptors (mainly mu) were presented in submucosal plexus. In concludes that alpha 2 adrenergic activity and other humoral factors seems to take an important role for the initiation of phasic contraction and to control maintenance of IMC cycle.