Christian de Duve glucagon was the major hormone influencing the breakdown of glycogen (glycogenolysis) in the liver, by which more sugars are produced in the blood. De Duve's original hypothesis that glucagon was produced by pancreatic alpha cells was proved right when it was demonstrated that selectively cobalt-damage alpha cells stopped producing glucagon in guinea pigs, and finally isolated the purified hormone in 1953, including those from birds. De Duve was the first to hypothesise that production of insulin to decrease blood sugar level stimulated the uptake of glucose in the liver, and that there is a balanced production of insulin and glucagon
Alpha cell Alpha cell Alpha cells (more commonly alpha-cells or α-cells) are endocrine cells in the pancreatic islets of the pancreas. They make up to 20% of the human islet cells synthesizing and secreting the peptide hormone glucagon, which elevates the glucose levels in the blood. To elevate glucose levels, glucagon binds to receptors on hepatocytes (liver cells) and some other cells (e.g. kidney cells). This activates an enzyme, glycogen phosphorylase, inside the hepatocyte to hydrolyse glycogen to glucose. This process is called glycogenolysis. In rodents, alpha cells are located in the periphery of the islets, however in humans the islet architecture