What is the main action of ACE inhibitors in managing hypertension?

The primary action of ACE inhibitors in managing hypertension is to block the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor and has a significant role in the regulation of blood pressure. By inhibiting the enzyme that converts angiotensin I to angiotensin II, ACE inhibitors lead to decreased levels of angiotensin II in the bloodstream. This results in vasodilation, reduced blood volume, and ultimately a decrease in blood pressure.

Furthermore, the reduction in angiotensin II also leads to decreased secretion of aldosterone, which normally would promote sodium and water retention. Therefore, the action of ACE inhibitors not only lowers blood pressure directly through vasodilation but also indirectly reduces fluid volume, further helping to manage hypertension effectively.