What Is the Connection between Angiotensin and Blood Pressure?

Angiotensin and blood pressure have a direct link, as this peptide acts on the smooth muscle in the blood vessel walls to constrict them, causing blood pressure to rise. The body naturally produces angiotensin when blood pressure drops to elevate it and return the blood pressure to normal. Patients with chronic hypertension may take medications to limit angiotensin production. This will force their blood pressure into a lower zone. A doctor may supervise the patient while she takes the medication, to provide interventions if the patient experiences complications or side effects.

The connection between angiotensin and blood pressure starts with the renin-angiotensin system in the kidneys. When the kidneys detect that blood pressure is low, they retain salts and water to elevate blood volume. The kidneys can also release renin into the bloodstream. The renin encounters a protein called angiotensinogen and splits it, generating angiotensin I. When angiotensin-converting enzyme (ACE) mixes with angiotensin I, it creates angiotensin II, which can trigger the blood vessels to constrict.

Patients with high blood pressure may take medications known as ACE inhibitors to break the angiotensin and blood pressure link by making less of this peptide available. If a patient doesn't tolerate these medications or they are not suitable for other reasons, he can take angiotensin II receptor blockers to limit the effect of this compound on the blood vessels. The medications compete at the receptor sites on the muscles to make it harder for the angiotensin to work.

The balance between angiotensin and blood pressure is a reflection of the self-regulatory systems throughout the body that work to maintain homeostasis. The kidneys and other organs keep blood pressure stable and also regulate other activities in the body. When something goes wrong, these systems can get out of alignment, and the patient may develop health problems. Treatment for high blood pressure may involve a number of measures, including diet and exercise recommendations in addition to beneficial medications.

Awareness of the link between angiotensin and blood pressure can be important for doctors and patients. When a patient has uncontrolled blood pressure that does not respond to conservative treatment, it may be necessary to consider medications to interfere with the renin-angiotensin cycle. These medications can have serious side effects, as they may cause interference with other physical systems in their attempt to regulate blood pressure. This may make it more difficult to maintain homeostasis, and the patient could need to make some lifestyle changes to compensate.