How do ACE inhibitors lower blood pressure?

ACE inhibitors lower blood pressure primarily by blocking the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor that, when formed, leads to an increase in blood pressure through various mechanisms, including the contraction of blood vessels and stimulation of aldosterone secretion, which promotes sodium and water retention by the kidneys.

By inhibiting the enzyme that facilitates this conversion (angiotensin-converting enzyme), ACE inhibitors effectively reduce the levels of angiotensin II in the bloodstream. This results in vasodilation, decreased blood vessel resistance, and ultimately a reduction in blood pressure. Moreover, lowering angiotensin II levels reduces aldosterone production, leading to decreased blood volume due to less sodium and water reabsorption by the kidneys.

This mechanism emphasizes the importance of regulating the renin-angiotensin-aldosterone system (RAAS) in the treatment of hypertension, making the role of ACE inhibitors crucial in managing high blood pressure effectively.