FETAL-RAT PANCREAS TRANSPLANTATION IN BB RATS - IMMUNOHISTOCHEMICAL AND FUNCTIONAL-EVALUATION

Spontaneously diabetic BB/Wor rats received either a syngeneic fetal p ancreas transplant or adult islets. In the former, 4-8 fetal pancrease s were transplanted, and in the latter, 3-5000 islets. Transplantation was performed by transferring a blood clot containing the pancreases or islets to the renal subcapsular space. Insulin therapy was undertak en postoperatively, except in one experiment with adult islets. Of the fetal pancreas transplanted BB rats, 52% became normoglycaemic, and 2 1% remained so throughout an observation period of 10 months. Nephrect omy caused a prompt return of diabetes. The histological appearance of the grafts transplanted to the diabetic animals closely resembled tha t of grafts transplanted to normal rats in a parallel series. For comp arison a group of BB rats received a syngeneic transplant of isolated adult islets from WF rats or BBW rats. Following adult islet transplan tation, 5 out of 6 animals became hyperglycaemic after a median of 20. 5 days when no insulin was given post-transplantation. Four out of 5 a nimals became hyperglycaemic after a median of 23 days when supportive insulin therapy was administered after the transplantation. The resul ts indicate that recurrent diabetes is not inevitable following syngen eic fetal pancreas transplantation to spontaneously diabetic BB rats. Recurrent diabetes was only occasionally associated with mononuclear c ell infiltration. Transplanted tissue was well-preserved and vasculari zed; mega-islets were a constant finding.