Short-term culture of adult pancreatic fragments for purification and transplantation of islets of Langerhans

Abstract

Minced adult human, rat, and dog pancreatic fragments were cultured under various conditions in an attempt to selectively purify pancreatic islet tissue from exocrine digestive enzymes. Islet purification was assessed by measuring tissue insulin and amylase concentrations, proportional to islet beta cell mass and exocrine enzyme content, respectively. Tissue amylase content decreased rapidly over a 24 hour culture period under all conditions. By addition of pilocarpine, cobalt chloride, and aprotinin to the culture medium, pancreatic tissue insulin levels stabilized. Under these conditions the tissue insulin: amylase ratio increased rapidly and a high ratio was maintained, indicating that islet tissue decontaminated of exocrine digestive enzymes was preserved in short-term culture. Fifteen dogs rendered diabetic with streptozotocin immediately following a partial pancreatectomy received an autotransplant of pancreatic tissue fragments maintained in culture for 24 hours. Seven dogs were rendered normoglycemic. Six of these dogs have survived for longer than 30 days. Only one of 14 control pancreatectomized dogs injected with streptozotocin and not transplanted survived and was normoglycemic. Viable islet tissue free of exocrine enzymes can be obtained by short-term culture of pancreatic fragments, and separation of islet and exocrine components of adult pancreas is not essential for successful islet transplantation.