Hormones are chemicals that act as "messengers" in the body, carrying information and instructions from one group of cells to another. Hormones that are important to understanding diabetes include: * Glucagon -- released by the Alpha cells in the pancreas; tells the liver to increase blood glucose levels. * Insulin -- released by the Beta cells in the pancreas; allows glucose to enter muscle and fat cells to use as energy or to store as glycogen for later use.