J J Heydenrych

Induction of cell proliferation and differentiation in the pancreas of the adult Vervet monkey (Cercopithecus aethiops) : Preliminary results

Cellophane wrapping of the adult Syrian golden hamster pancreas has been found to result in ductular cell proliferation leading to islet regeneration. Injection of cytosol from a cellophane-wrapped pancreas into normal or diabetic hamsters evoked a similar response. In view of the therapeutic potential of the active substance in this cytosol, it was decided to investigate whether a similar response could be achieved in a primate. In normal adult Vervet monkey (Cercopithecus aerhiops) pancreas, proliferation is seen only rarely in islet cells and occasionally in duct and acinar cells. Immunohistochemi-cal investigation of normal Vervet monkey pancreas (n = 4) and 14 days (n = 2) and 56 days (n = 1) after cellophane wrapping of the Vervet monkey pancreas revealed a slight increase in proliferation of islet and acinar cells and a larger increase in proliferation of duct cells and in total endocrine cell volume. The results suggest that there is a latent developmental capability in the adult primate pancreas.

Prolongation of segmental and pancreaticoduodenal allografts in the primate with total-lymphoid irradiation and cyclosporine

The prolongation of segmental and pancreaticoduodenal allografts (PDA) by total lymphoid irradiation (TLI) and in combination with cyclosporine (CsA) was assessed in a well established total pancreatectomy, diabetic, primate transplantation model. Pancreatic transplantation was performed in 119 pancreatectomized baboons (Papio ursinus). Of a total of 109 allografts performed, 71 were segmental allografts (open duct drainage) and 38 PDA. Of 119 graft recipients, 10 received segmental pancreatic autografts. TLI and CsA administered separately to segmental allograft recipients resulted in modest allograft survival and indefinite graft survival was not observed. 8 of 17 (47%) segmental allograft recipients that received TLI and CsA had graft survival beyond 100 days, indicating highly significant pancreatic allograft survival. All long-term segmental allograft recipients were rendered normoglycemic (plasma glucose less than 8 mmol/L) by this immunosuppressive regimen. In contrast, poor results were observed in PDA recipients treated with TLI and CsA. Mean survival in 18 treated PDA recipients was 23.8 days, 8 survived longer than 20 days (44.4%), and 1 greater than 100 days (5.5%). Despite treatment, early rejection of the duodenum in PDA recipients frequently resulted in necrosis and perforation and contributed to a high morbidity and mortality. This study indicates that, in contrast to the significant prolongation of segmental allografts by TLI and CsA, poor immunosuppression was achieved by this regimen in PDA recipients and was associated with a high morbidity and mortality caused by early rejection of the duodenum.