Regeneration of sympathetic activities in small bowel transplants.

In order to study the activity of noradrenergic nerve fibres along mesenteric arteries in small-intestinal grafts, the entire jejunoileum was transplanted heterotopically in an isogeneic rat model (group I, n = 12). To assess their influence on graft motility, 9 cm of jejunum were transplanted in an orthotopic position and three bipolar electrodes sutured to the seromuscular layer of the graft (group II, n = 10). Fasting motility was recorded up to postoperative day 42. Animals of group I were sacrificed from day 7 on at weekly intervals and mesenteries were analysed histochemically by fluorescence microscopy. After the 1st and 2nd week, grafts were found to be completely depleted of noradrenaline. At the end of the 3rd week, fluorescence became detectable along graft mesenteric arteries and showed normal intensity from the end of week 4. Migrating myoelectric complexes (MMCs) were present in all animals of group II. The variability of the MMC period (mean 12.6 min; SD 6.2 min) expressed as variation coefficient (median 36.5; 14.6-74) did not change during the observation period. From these findings it is concluded that there are no extrinsic noradrenergic activities in rat small-intestinal transplants for the first 3 postoperative weeks but they do recover there after. Their influence on graft function remains unclear: MMC periodicity, however, was no influenced.