Reinnervation of Pancreatic Islets and Regulation of Insulin Secretion by Hepatic Sympathetic Nerves after Intraportal Transplantation of Islets into Livers of Diabetic Rats

Summary

It was the aim of this study to elucidate whether intraportally transplanted pancreatic islets were reinnervated after transplantation and whether the secretion of insulin from pancreatic islets might be modulated by the vegetative innervation of recipient livers. Two weeks after intraportal transplantation of 2000 neonatal pancreatic islets recipient rats completely recovered from streptozotocin-induced diabetes. Predominantly catecholaminergic, but also cholinergic nerve fibers were detected in islet cell complexes between β-cells. Corresponding electron micrographs showed β-cells in close contact with axons of nonmyelinated nerve fibers. Perfusion studies with livers of recipient rats revealed that the inhibition by hepatic sympathetic nerves of insulin secretion was mediated via α₂-receptors as in normal pancreatic islets.

Key words

Morphology - Electron microscopy - Perfused liver - Glucose metabolism - α-adrenergic receptors - β-adrenergic receptors