Preservation of islet function and morphology after transplantation into high dose streptozotocin-diabetic rats.

Rats made diabetic with 0.15 g/kg streptozotocin showed a complete absence of islet B cells in their pancreases, even after 3-6 months of normoglycaemia. Glucagon- and somatostatin-containing cells were preserved. In these animals transplantation of 5,000 cultured fetal islets was required to restore normal blood glucose and intermediary metabolite profiles after a meal challenge, while 2,000 islets resulted in a marked metabolic disturbance. The larger number of islets produced comparable effects whether transplanted under the kidney capsule or into the splenic pulp. In either site, however, considerable proliferation of adipose tissue was found by 3-6 months. Transplanted islets were then demonstrated to retain the normal morphology with a central mass of insulin-containing cells surrounded by a ring of A cells in which a few D cells were embedded.