Angiotensin-converting enzyme (ACE)

Definition

Angiotensin-converting enzyme (ACE) is an important enzyme in the renin-angiotensin system that converts angiotensin I, an inactive precursor, into angiotensin II, a potent vasoconstrictor. This process plays a crucial role in regulating blood pressure and fluid balance within the body, as angiotensin II leads to increased vascular resistance and stimulation of aldosterone secretion, which ultimately affects sodium and water retention.

5 Must Know Facts For Your Next Test

1. ACE inhibitors are commonly prescribed medications that block the action of ACE, leading to lower blood pressure and decreased workload on the heart.
2. The regulation of ACE activity is critical for maintaining homeostasis in the cardiovascular system and can be influenced by factors like sodium intake and blood volume.
3. ACE is primarily found in the lungs but is also present in other tissues like the kidneys and blood vessels, where it contributes to local regulation of blood pressure.
4. Elevated levels of angiotensin II due to increased ACE activity can lead to conditions such as hypertension, heart failure, and kidney disease.
5. The interaction between ACE and other components of the renin-angiotensin system is a key target for understanding cardiovascular health and developing therapeutic interventions.

Review Questions

• How does angiotensin-converting enzyme (ACE) contribute to the regulation of blood pressure?
  • ACE contributes to blood pressure regulation by converting angiotensin I into angiotensin II, which is a potent vasoconstrictor. When angiotensin II levels rise, they cause blood vessels to constrict, leading to an increase in vascular resistance and, consequently, elevated blood pressure. Additionally, angiotensin II stimulates aldosterone secretion from the adrenal glands, promoting sodium and water retention, further increasing blood volume and blood pressure.
• Discuss the implications of using ACE inhibitors in managing hypertension and their mechanism of action.
  • ACE inhibitors are a class of medications used to manage hypertension by blocking the activity of angiotensin-converting enzyme. By inhibiting ACE, these drugs reduce the conversion of angiotensin I to angiotensin II, resulting in lower levels of this potent vasoconstrictor. This leads to vasodilation and decreased vascular resistance, ultimately lowering blood pressure. The use of ACE inhibitors also decreases aldosterone secretion, which helps reduce fluid retention and further supports blood pressure reduction.
• Evaluate how abnormalities in ACE function can affect overall cardiovascular health and lead to diseases.
  • Abnormalities in ACE function can significantly impact cardiovascular health by disrupting the delicate balance of the renin-angiotensin system. An overactive ACE can lead to excessive production of angiotensin II, resulting in chronic hypertension, increased cardiac workload, and eventual heart failure. Conversely, reduced ACE activity may impair normal blood pressure regulation and contribute to conditions like hypotension. Understanding these abnormalities allows for better treatment strategies targeting cardiovascular diseases linked to dysregulation of this critical enzyme.

Related terms

Renin: An enzyme secreted by the kidneys that initiates the renin-angiotensin system by converting angiotensinogen into angiotensin I.

Angiotensin II: A powerful vasoconstrictor that is produced from angiotensin I by the action of ACE; it increases blood pressure and stimulates aldosterone release.

Aldosterone: A hormone produced by the adrenal glands that promotes sodium retention in the kidneys, which helps to regulate blood volume and blood pressure.