Viable purified islets of Langerhans from collagenase-perfused human pancreas.

Human islets of Langerhans were isolated with the principles of collagenase perfusion via the pancreatic duct and gentle dissociation of tissue. The number of islets released was 161 x 10(3), distributed as 76 x 10(3) large (greater than 100-micron) and 85 x 10(3) small (less than 100-micron) islets. Recovery after Ficoll-gradient purification was 61% for the large islets and 42% for the small islets. The final islet volume was 240 microliter, with purity of 70-90% (large islets) and 20-40% (small islets). Perifusion with glucose elicited a biphasic release of insulin, with the response rising sixfold from basal secretion. Implantation of pure islets under the kidney capsule of normal or streptozocin-induced diabetic nude mice resulted in human C-peptide secretion and partial or complete reversal of hyperglycemia, confirmed by histological recovery. The data show that these methods provide large quantities of viable purified human islets.