What is the primary mechanism of action of ACE inhibitors?

ACE inhibitors primarily function by inhibiting the conversion of angiotensin I to angiotensin II. This mechanism is crucial in the renin-angiotensin-aldosterone system (RAAS), which plays a significant role in regulating blood pressure and fluid balance.

By blocking this conversion, ACE inhibitors lead to decreased levels of angiotensin II, a potent vasoconstrictor. The reduction of angiotensin II results in vasodilation, which lowers blood pressure. Furthermore, it decreases the secretion of aldosterone, leading to reduced sodium and water retention by the kidneys, subsequently lowering blood volume and further aiding in blood pressure reduction.

The inability of ACE inhibitors to engage in activities such as blocking calcium channels, increasing heart rate, or promoting sodium retention underlines the specificity of their action within the cardiovascular system, making them effective tools for managing hypertension and heart failure.