Promising developments in new treatments for diabetes involving glucagon
Role of glucagon action
Glucagon is secreted by the pancreatic alpha cells mainly stimulated by changes in local concentration of glucose, amino acids and insulin and through the autonomic (vegetative) nervous system. Recently, it has been demonstrated that sodium-glucose co-transporter 2 (SGLT-2) is expressed in pancreatic alpha cells, designated for an inhibitory effect on glucagon release in the range of physiological glucose concentrations . The endocrine effects on the liver include the activation on the glucagon receptor (GCGR), a G-protein-coupled receptor (GPCR), and engagement of the GαS and β-arrestin pathways (signalling cascades). Glucagon initiates the increase in the export of glucose from the liver as a result of enhanced glycogenolysis and gluconeogenesis [2, 3, 4, 5].