What are ACE inhibitors, and how do they work?
Angiotensin II is a very potent chemical produced by the body that causes the muscles surrounding blood vessels to contract, thereby narrowing the vessels. The narrowing of the vessels increases the pressure within the vessels causing increases in blood pressure (hypertension). Angiotensin II is formed from angiotensin I in the blood by the enzyme angiotensin converting enzyme (ACE). ACE inhibitors are medications that slow (inhibit) the activity of the enzyme ACE, which decreases the production of angiotensin II. As a result, the blood vessels enlarge or dilate, and blood pressure is reduced. This lower blood pressure makes it easier for the heart to pump blood and can improve the function of a failing heart. In addition, the progression of kidney disease due to high blood pressure or diabetes is slowed.