[Models and perspectives of pancreas transplantation in the rat. I. Comparison of various transplantation models in the syngeneic system].

Pancreas transplants were grafted in rats using five different microsurgical techniques. Three of the techniques allowed exocrine drainage, namely pancreaticoduodenal transplantation, grafts with a duodenal patch, and grafts with exocrine drainage via a Roux-en-y-loop. Segmental transplants in which the duct system was ligated or occluded with Ethibloc were used as models without exocrine drainage. Donors and recipients were Lewis rats. Diabetes was induced in the recipients with streptozocin. Regular measurements of serum glucose and body weight served as functional controls. At the end of the observation period, the grafts were examined macroscopically and microscopically. Basically, all types of grafts allowed normalization of the blood sugar level. In grafts with ligated or occluded ducts, however, we observed functional failure due to fibrosis or abscesses. It became obvious that all grafts without exocrine drainage are subject to alternative processes that lead to the loss of exocrine tissue, to proliferation of the pancreatic ducts and to morphological changes in the islets. In successfully drained grafts, the morphology of the organ is lastingly preserved. In the rat model the most reliable management of exocrine drainage is afforded by pancreaticoduodenal grafts.