High blood pressure

What's an angiotensin converting enzyme?

Angiotensin converting enzyme inhibitors (also called ACE inhibitors) are drugs that are used to treat high blood pressure. But what is an angiotensin converting enzyme?

"A" stands for angiotensin, a chemical that your body makes when it notices that less blood is being pumped around it. (Your blood carries the oxygen and food that all the cells in your body need.) Angiotensin has two forms, angiotensin I and angiotensin II.

Angiotensin I tries to control how much blood is circulating around your body. If less blood is circulating, angiotensin I makes your body save salt and water. It does this to try to increase the amount of fluid circulating through your blood vessels.
Angiotensin I also makes your blood vessels narrower and raises your blood pressure. Over time, this can make the chamber on the lower left side of your heart (called the left ventricle) flabby. This means that it doesn't pump as well as it should.
Angiotensin I is changed into a more active chemical called angiotensin II. And this chemical makes the heart use more oxygen than usual to pump, which in turn makes your blood pressure go up.

The "C" and "E" stand for converting enzyme.

This is the chemical in the body that makes angiotensin I become angiotensin II.
ACE inhibitors stop the angiotensin converting enzyme from working.

This information was last updated on Jul 02, 2009

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