Culture of islets of Langerhans from an infant with intractable neonatal hypoglycemia: cytochemical and radioimmunological studies.

Extralobular islet of Langerhans cells were isolated from the pancreas of an infant with intractable neonatal hypoglycemia (nesidioblastosis) by digestion with a mixture of trypsin and collagenase, and subsequent purification on a gradient of fetal calf serum. These islet cells cultured in Eagle's medium containing 20% fetal calf serum formed confluent endocrine cell monolayers within 15 days. These endocrine cells were studied immunocytochemically, and their secretion products were assayed by radioimmunological methods. The large numbers of beta, alpha and delta cells present in the islets before explanation remained functional in the cultures for 30 days. The beta cells secreted large amounts of insulin throughout this period, and secretion was stimulated by raising the glucose concentration in the medium from 5.6 to 16.8 mM. Initially there was little secretion of glucagon, but this increased during the subsequent 10 days in culture. It was not inhibited when the glucose concentration was raised from 5.6 to 16.8 mM. Somastostatin secretion remained stable throughout the period of culture, but tended to rise when the glucose concentration was increased. These results show that the culture of pancreatic cells from infants with nesidioblastosis provides an interesting in vitro system for studying the biological and biochemical characteristics of endocrine cells in the human pancreas.