Alpha cells are present in the pancreas. They are present in the pancreatic islets or the islets of Langerhans (a part of the pancreas). They release a hormone called glucagon (peptide hormone), which is responsible for the steady level of blood sugar level in between meals. It can even lead to elevated blood sugar levels in diabetic patients. Glucagon is released when the body sends signals to the alpha cells during periods of low blood glucose levels. Glucagon reaches the liver where it then signals it to release glucose into the blood. In people with diabetes, the alpha cells are not damaged.