What do alpha cells do?

• A. Store glucose
• B. Produce glucagon
• C. Regulate blood pressure
• D. Produce insulin

Answer: (B)

Alpha cells are part of the pancreatic islets and specialize in secreting glucagon. This hormone raises blood glucose levels when you’re fasting or have low blood sugar by signaling the liver to break down stored glycogen (glycogenolysis) and to synthesize new glucose from non-carbohydrate sources (gluconeogenesis). It can also promote the breakdown of fats for energy. Glucagon’s action is the opposite of insulin, which lowers blood glucose by helping cells take in glucose. So alpha cells don’t store glucose, don’t directly regulate blood pressure, and don’t produce insulin—the latter is the job of beta cells.