Do ACE inhibitors affect blood vessels?

Yes, ACE inhibitors (angiotensin-converting enzyme inhibitors) affect blood vessels by causing their dilation and relaxation. Here's how ACE inhibitors influence blood vessels:

1. Renin-Angiotensin-Aldosterone System Inhibition: ACE inhibitors block the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor that causes blood vessels to narrow. By inhibiting ACE, ACE inhibitors reduce angiotensin II levels, leading to vasodilation (widening) of blood vessels.

2. Bradykinin Potentiation: ACE inhibitors also prevent the breakdown of bradykinin, a vasodilator substance in the body. By increasing bradykinin levels, ACE inhibitors further contribute to blood vessel relaxation.

3. Nitric Oxide Production: ACE inhibitors stimulate the production of nitric oxide (NO), a powerful vasodilator. NO signals the blood vessels to relax, resulting in decreased peripheral resistance and improved blood flow.

4. Reduction in Sympathetic Tone: ACE inhibitors may reduce the activity of the sympathetic nervous system, which is responsible for vasoconstriction. By lowering sympathetic tone, ACE inhibitors can help to further relax blood vessels.

As a result of these actions, ACE inhibitors promote vasodilation and decrease blood vessel resistance. This can lower blood pressure, improve blood flow, and reduce the workload on the heart. ACE inhibitors are commonly prescribed to manage hypertension (high blood pressure), heart failure, and other cardiovascular conditions where blood vessel relaxation is beneficial.