Which statement about ACE inhibitors is true?

• A. They block AT1 receptors for angiotensin II, reducing its effects.
• B. They block conversion of angiotensin I to angiotensin II, decreasing vasoconstriction; bradykinin accumulation can cause a dry cough.
• C. They increase aldosterone release, leading to volume expansion.
• D. They inhibit renin release from juxtaglomerular cells.

Answer: (B)

ACE inhibitors work by blocking the enzyme that converts angiotensin I to angiotensin II. With less angiotensin II, there is reduced vasoconstriction and less aldosterone-driven sodium and water retention, which lowers blood pressure. A second effect is that this enzyme also breaks down bradykinin; when it’s inhibited, bradykinin accumulates, and that buildup can trigger a dry cough. This combination—blocking the formation of the vasoconstrictor angiotensin II and allowing bradykinin to rise—explains why the statement is true. The other ideas don’t fit: blocking AT1 receptors is the mechanism of ARBs, not ACE inhibitors; ACE inhibitors do not increase aldosterone, they decrease it; and they do not inhibit renin release—in fact, renin activity can rise due to loss of feedback inhibition.