Glucagon receptor signaling in metabolic diseases.

Glucagon is a peptide hormone secreted from the pancreatic alpha cells in response to hypoglycemia but in some patients with type 2 diabetes a paradoxical hypersecretion results from the intake of glucose. In rodent, antagonizing the actions of glucagon have been shown to be effective for lowering blood glucose levels and this has recently have been solidified in patients with type 2 diabetes. Although the reported increases of liver enzymes, hyperglucagonemia, and alpha cell hyperplasia resulting from glucagon receptor antagonism may potentially limit the clinical applicability of glucagon receptor antagonists, they may serve as an instrumental toolbox for delineating the physiology of glucagon. Agonizing glucagon receptor signaling may be relevant, in particular when combined with glucagon-like peptide-1 receptor analogues in the perspective of body weight lowering therapy. Here, we will focus on new conceptual aspects of glucagon biology and how this may led to new diagnostics and treatment of metabolic diseases.