The glucagon receptor is a 62 kDa peptide that is activated by glucagon and is a member of the G-protein coupled family of receptors, coupled to Gs. Stimulation of the receptor results in activation of adenylate cyclase and increased levels of intracellular cAMP. Glucagon receptors are mainly expressed in liver and in kidney with lesser amounts found in heart, adipose tissue, spleen, thymus, adrenal glands, pancreas, cerebral cortex, and gastrointestinal tract.This is a receptor for glucagon which plays a central role in regulating the level of blood glucose by controlling the rate of hepatic glucose production and insulin secretion. The activity of this receptor is mediated by G proteins which activate adenylyl cyclase and also a phosphatidylinositol-calcium second messenger system.