Insulin signal transduction pathway is secreted after glucose enters the beta cell and that triggers several other processes in a chain reaction. While insulin is secreted by the pancreas to lower blood glucose levels, glucagon is secreted to raise blood glucose levels. This is why glucagon has been known for decades as a counter-regulatory hormone. When blood glucose levels are low, the pancreas secretes glucagon, which in turn causes the liver to convert stored glycogen polymers into glucose monomers, which is then released into the blood. This process is called glycogenolysis. Liver cells, or hepatocytes, have glucagon receptors which allow for glucagon to attach
Blood sugar regulation cells in the pancreatic islets are among the most well understood and important. If the blood glucose level falls to dangerous levels (as during very heavy exercise or lack of food for extended periods), the alpha cells of the pancreas release glucagon, a hormone whose effects on liver cells act to increase blood glucose levels. They convert glycogen into glucose (this process is called glycogenolysis). The glucose is released into the bloodstream, increasing blood sugar. Hypoglycemia, the state of having low blood sugar, is treated by restoring the blood glucose level to normal by the ingestion or administration of dextrose