Background: The aim of this study was to compare the functional maturation of neonatal porcine islet (NPI) grafts exposed to long-term hyperglycemia with those implanted under euglycemic conditions.
Methods: mice Neonatal porcine islets were transplanted under the left renal capsule of diabetic SCID mice (group H), or in diabetic SCID mice who were also implanted with 500 BALB/c islets under the right renal capsule (group N). On day 42, the right kidneys were removed in both groups.
Results: No animals in group H achieved euglycemia within 3 weeks after transplantation. Thus, these mice were exposed to long-term hyperglycemia. Mice in group N became euglycemic immediately after transplantation, however after removal of BALB/c grafts on day 42 they exhibited significantly higher blood glucose levels than in group H and showed glucose intolerance after glucose administration. Cellular insulin content of NPI grafts harvested on day 58 or 72 was significantly lower in group N mice compared to group H.
Conclusions: These results suggest that tight control of glycemia reduces the functional maturation of NPI grafts.