Which of the following is a primary function of BNP?

• A. Regulate blood sugar levels
• B. Increase fluid excretion from kidneys
• C. Stimulate red blood cell production
• D. Decrease bile production

Answer: (B)

B-type natriuretic peptide (BNP) is a hormone produced by the heart, specifically the ventricles. One of its primary functions is to promote natriuresis, which is the excretion of sodium through the urine, and subsequently increase fluid excretion from the kidneys. This action is crucial in regulating blood volume and blood pressure, particularly in conditions like heart failure.

By increasing fluid excretion, BNP helps reduce the workload on the heart and relieves symptoms associated with volume overload. This is particularly important in patients with heart failure, where retaining excess fluid can lead to worsening symptoms and complications.

The other options listed pertain to different physiological processes not directly influenced by BNP. For instance, regulating blood sugar levels is primarily managed by insulin and glucagon, stimulating red blood cell production relates to erythropoietin primarily produced by the kidneys, and bile production is typically regulated by hepatocytes under hormonal control rather than being influenced by BNP.