ABSTRACT
The impaired response by hepatic glucokinase activity to administration of glucose in aging rats in large part reflects an altered pattern of glucose-stimulated secretion of insulin. This chapter discusses the differences which characterize the perifused islet preparation as it is isolated and utilized from host rats of increasing age. It reviews implications of experimental data. Perifused, isolated islets provide a unique opportunity to study in an in vitro system, a phenomenon that characterizes intact organisms as they age. The rat is sacrificed by decapitation and a midline incision made with scissors. Suitable islets free of acinar tissue are transferred to a small petri dish using a pipette with a plastic tip. A failure of the biphasic insulin response to occur probably results from an overdigestion of the islets. The secretion pattern is blunter or there is a complete absence of the normal biphasic pattern of secretion.
