Neurohormonal regulation of the insulin stimulus-secretion coupling in pancreatic islets.

Type 2 diabetes mellitus, a major health care problem in the Western world, is a disease typified by a relative deficiency of insulin, leading to vast derangements in glucose and lipid homeostasis with disastrous vascular complications. Despite immense research efforts aiming at a clear understanding of the etiology of this complex disease, the molecular mechanisms causing the disorder still remain elusive. Here we review extant data from recent publications implicating novel signal transduction pathways and neurohormonal agonists as important regulators of the insulin stimulus-secretion coupling in the pancreatic beta-cell. Specifically, attention is paid to incretins such as glucagon-like peptide 1 (GLP-1), galanin, and other peptides produced in the gastrointestinal tract and by neuronal cells with the potential of governing beta-cell function in physiological and diabetic states.