Glucagon is a peptide hormone secreted by the alpha cells of the pancreas, and contrary to the action of insulin, glucagon is a blood glucose-raising hormone. The mechanism of glucagon’s action includes the following points: 1. Promote glycogenolysis, when blood glucose is lowered glucagon can promote the body’s stored glycogen into glucose to maintain blood glucose concentration. 2. Promote gluconeogenesis, glucagon can promote the conversion of non-glucose substances into glucose to promote the process of gluconeogenesis in order to maintain normal blood glucose concentration, so glucagon and insulin are the most important pair of hormones in the regulation of blood glucose. So glucagon and insulin are the most important pair of hormones in the body to regulate blood sugar. When blood glucose rises, glucagon secretion is inhibited and insulin secretion is promoted to lower blood glucose. When blood glucose decreases, glucagon secretion will be promoted and insulin secretion will be decreased to maintain normal blood glucose concentration.