Role of Hyperglycemia in Isogeneic Islet Transplantation: An Experimental Animal Study

Objective: Study the role of hyperglycemia-induced β cell loss on grafted islet destruction. Design: Male inbred rats were made diabetic by streptozotocin administration and used as islet donors and/or isograft recipients to probe directly the role of hyperglycemia as an important determinant of transplanted islet fate, following exclusion of immune-related causes of islet graft destruction like allograft immunity and disease recurrence. Results: Our studies showed that: a) Hyperglycemia destroyed islet but not pituitary isografts and b) Tight control of normoglycemia by sufficient islet mass engraftment prevented graft damage. Conclusion: While sustained hyperglycemia caused destruction of transplanted islet isografts, induction of normoglycemia by transplantation of sufficient islet mass to diabetic recipients had a beneficial long term effect on their functional engraftment.