Which hormone increases blood glucose during fasting?

• A. Insulin
• B. ADH
• C. Oxytocin
• D. Glucagon

Answer: (D)

During fasting, blood glucose must be kept from dropping too low, so the body relies on hepatic glucose production. When glucose is scarce, pancreatic alpha cells release glucagon. This hormone signals the liver to boost glucose output by breaking down glycogen (glycogenolysis) and by generating new glucose from non-carbohydrate sources (gluconeogenesis). The result is an increase in blood glucose to keep brain and other tissues supplied. Insulin does the opposite, promoting glucose uptake and storage, lowering blood glucose. ADH and oxytocin don’t play major roles in regulating blood glucose during fasting. Glucagon is the hormone that increases blood glucose in this state.