单选题 A client with heart failure asks the nurse about the reason for taking enalapril maleate. The nurse would explain that the medication is prescribed for which of the following reason

A、 Lower the blood pressure by increasing peripheral vasoconstriction.
B、 Lower the heart rate by slowing the conduetion system.
C、 Block the conversion of angiotensin Ⅰ to angiotensin Ⅱ.
D、 Increase myocardial contractility, thereby improving cardiac output.

【正确答案】 C

【答案解析】Enalapril maleate is an angiotensin-converting enzyme (ACE) inhibitor that prevents conversion of angiotensin Ⅰ to angiotensin Ⅱ. Angiotensin Ⅱ is a potent vasoconstrictor and also contributes to aldosterone secretion. Thus, enalapril decreases blood pressure through systemic vasodilation.