ACE inhibitors work by preventing the conversion of angiotensin I to angiotensin II. What is the primary result?

• A. Prevention of vasoconstriction
• B. Increased aldosterone release
• C. Diuresis only
• D. Increased heart rate

Answer: (A)

Blocking the formation of angiotensin II removes a major driver of vascular tone. Angiotensin II is a potent vasoconstrictor, so when its production is inhibited, blood vessels dilate and systemic vascular resistance drops, leading to lower blood pressure. Angiotensin II also stimulates aldosterone release, so reducing Ang II decreases aldosterone, which reduces sodium and water retention and contributes to diuresis and further volume lowering. ACE inhibitors can also increase bradykinin, which promotes additional vasodilation. Among the options, the primary result is the prevention of vasoconstriction, which directly explains the main therapeutic effect. The other choices describe secondary or less direct effects and are not the primary outcome.