[Models and perspectives of pancreas transplantation in the rat. II. Course of rejection of pancreaticoduodenal transplants of various histoincompatibility and the effect of temporary therapy with cyclosporin (Sandimmun)].

Pancreaticoduodenal grafts were transplanted into streptozocin-induced diabetic recipients. Recipients of syngeneic grafts survived long term with functioning grafts. To investigate the rejection reaction in pancreaticoduodenal allografts, the organs were grafted in an MHC compatible but non-MHC incompatible strain combination (AS----LEW) and in a combination that is both MHC and non-MHC incompatible (DA----LEW). The functioning times were 12.4 +/- 4.0 days in the AS----LEW group and 8.2 +/- 0.6 days in the DA----LEW group. A histologic study of the course of the rejection process showed that first the exocrine portion of the grafts, then the endocrine tissue, and finally the duodenum was destroyed. After the recipients of allografts were treated with an oral dose of 15 mg/kg/day Ciclosporin (Sandimmun) for 14 days p.op., the functioning times of the grafts increased to 47.5 +/- 14.4 days in the AS-LEW group and 26.0 +/- 0.5 days in the DA-LEW group. Histologic investigations showed that during the period in which Ciclosporin was given, only perivascular round cell infiltrates appeared with no visible destruction of the graft. After discontinuation of the medication basically the same histologic alterations occurred as in untreated allografts, however with a delay.