Intrapancreatic islet transplantation in experimental diabetes in the rat.

Pancreatic islets have been transplanted successfully to a variety of organs except the pancreas. Since this organ is the most physiologic recipient for islets in rodents with chemically induced diabetes, we have placed neonatal islets intrapancreatically in highly inbred Lewis rats with streptozotocin (ST) diabetes. Transplantation of 2,000 neonatal islets into the pancreas of diabetic rats reversed diabetes within 2 weeks in all of the treated rats (seven of seven). The same success rate was obtained using the same number of islets placed under the kidney capsule in 11 recipients. Although cured of their diabetes, rats in both groups with inadequate islet-cell mass were not able to produce glucose tolerance tests equal to those observed in normal animals. Higher insulin levels were measured in the rats receiving islets under the kidney capsule, as compared with those placed intrapancreatically. In summary, syngeneic islet transplants to the pancreas of ST-diabetic rats are successful in reversing the diabetic state. This model may be useful to the study of islet function after islet transplants into their natural environment.