What is the main function of the atrial natriuretic peptide secreted by the heart in heart failure?

What is the main function of the atrial natriuretic peptide secreted by the heart in heart failure?

• A. Decreased glomerular filtration rate
• B. Inhibition of renin release
• C. Induction of vasoconstriction
• D. Stimulation of aldosterone release

Answer: (B)

Atrial natriuretic peptide acts to counteract volume overload by opposing the renin–angiotensin–aldosterone system. When the heart is stretched in heart failure, ANP is released and its key action is to inhibit renin release from the juxtaglomerular cells. This blunts the production of angiotensin II and aldosterone, reducing sodium and water reabsorption, promoting natriuresis/diuresis, and helping to lower preload and blood pressure. While ANP can increase GFR and cause vasodilation, the clinically important mechanism in this setting is renin inhibition, which is why the correct choice emphasizes inhibition of renin release. The other effects don’t align with ANP’s actions: it does not promote vasoconstriction or stimulate aldosterone release, and it tends to support or enhance GFR rather than decrease it.

Atrial natriuretic peptide acts to counteract volume overload by opposing the renin–angiotensin–aldosterone system. When the heart is stretched in heart failure, ANP is released and its key action is to inhibit renin release from the juxtaglomerular cells. This blunts the production of angiotensin II and aldosterone, reducing sodium and water reabsorption, promoting natriuresis/diuresis, and helping to lower preload and blood pressure. While ANP can increase GFR and cause vasodilation, the clinically important mechanism in this setting is renin inhibition, which is why the correct choice emphasizes inhibition of renin release. The other effects don’t align with ANP’s actions: it does not promote vasoconstriction or stimulate aldosterone release, and it tends to support or enhance GFR rather than decrease it.