Experimental vascularized segmentai pancreatic and islet transplantation in the baboon

Abstract

The present study was undertaken to evaluate the effectiveness of cyclosporine (CYA) and total body irradiation (TBI) or total lymphoid irradiation (TLI) in suppressing segmental pancreatic allograft rejection in totally pancreatectomized outbred Chacma baboons. In addition, the study includes our preliminary results with subcapsular renal autotransplantation of dispersed autologous pancreas in the primate.CYA in doses of 25-50 mg/kg per day produced a slight but significant prolongation of graft survival. There was a wide variation of daily CYA serum trough levels exhibited between primates on the same daily oral dose, and there was no clear correlation between absolute CYA serum trough levels and rejection. Although heterotopic auto-or allotransplantation of the tail of the pancreas in the baboon was capable of maintaining normoglycemia in pancreatectomized baboons until rejection of the graft, glucose intolerance, reduced K-values, and hypoinsulinemia were consistent findings during glucose tolerance tests, suggesting transplantation of an insufficient islet cell mass.Animals that received 76 rad (TBI) remained normoglycemic between 14 and 36 days with a median of 22 days, which indicated a modest but significant prolongation of graft survival. Animals treated with TLI (600 rad) sustained graft function between 7 and 31 days with a median of 17 days. The optimal regimen of irradiation in terms of cumulative dose, dose per fraction, number of fractions, and frequency of irradiation still requires refinement in this model.

The effect of ionizing radiation on the primate pancreas: An endocrine and morphologic study

“…A standard primate pellet was given (Epol, South Africa: protein 200 gm/kg, moisture 100 gm/kg, fat 25 gm/kg, phosphorus 8 gm/kg, fibre 50 gm/kg, calcium/phosphorus ratio 1.1-1.5: 1 .O; vitamin C 50 gmlkg). Contrary to our previous technique [3,4], anaesthetized primates in this study received modified fractionated, subtotal marrow irradiation with shielding of the head, arms, and legs. This amounted to near total body irradiation.…”

“…During the period of irradiation the animals were given free access to food and water. A standard primate pellet was given (Epol, [3,4], anaesthetized primates in this study received modified fractionated, subtotal marrow irradiation with shielding of the head, arms, and legs. This amounted to near total body irradiation.…”