Glucagon is a peptide hormone secreted by the alpha cells of the pancreas. The functions of glucagon are as follows: i. Inhibit glucose utilization and promote the breakdown of liver glycogen into glucose to maintain blood glucose concentration. Therefore, when the blood glucose concentration decreases, the body will promote insulin secretion to raise blood glucose. Second, glucagon is a pro-catabolic hormone that promotes the breakdown of protein and fat, inhibits the synthesis of protein and fat, provides raw materials for gluconeogenesis, and raises blood glucose by enhancing the gluconeogenesis pathway, so glucagon has the effect of significantly raising blood glucose, and is a hormone with diametrically opposite effects to insulin secreted by pancreatic beta cells. Glucagon and insulin are important hormones that regulate blood glucose, and they work together to keep blood glucose in a state of dynamic equilibrium.