Which statement about ACE inhibitors is true?

Which statement about ACE inhibitors is true?

• A. They block the angiotensin-converting enzyme, reducing Ang II formation.
• B. They block AT1 receptors for angiotensin II.
• C. They directly inhibit renin activity.
• D. They cause cough by degrading bradykinin.

Answer: (A)

ACE inhibitors work by blocking the angiotensin-converting enzyme, which normally converts angiotensin I to angiotensin II. With this enzyme blocked, Ang II formation falls, leading to less vasoconstriction and less aldosterone-driven sodium and water retention, so blood pressure drops. An additional effect is that ACE also degrades bradykinin; when ACE is inhibited, bradykinin levels rise, which can contribute to a dry cough in many patients. Others choices describe different mechanisms: blocking AT1 receptors is how ARBs work, not ACE inhibitors; directly inhibiting renin is the action of renin inhibitors; and the cough is due to bradykinin accumulation from reduced breakdown, not degradation.

ACE inhibitors work by blocking the angiotensin-converting enzyme, which normally converts angiotensin I to angiotensin II. With this enzyme blocked, Ang II formation falls, leading to less vasoconstriction and less aldosterone-driven sodium and water retention, so blood pressure drops. An additional effect is that ACE also degrades bradykinin; when ACE is inhibited, bradykinin levels rise, which can contribute to a dry cough in many patients. Others choices describe different mechanisms: blocking AT1 receptors is how ARBs work, not ACE inhibitors; directly inhibiting renin is the action of renin inhibitors; and the cough is due to bradykinin accumulation from reduced breakdown, not degradation.