Answer: ACE inhibitors:
Mode of Action:
Angiotensin Converting Enzyme inhibitors (ACE inhibitors) are a class of medications commonly used to treat high blood pressure (hypertension) and heart failure. They work by targeting the renin-angiotensin-aldosterone system (RAAS), which plays a significant role in regulating blood pressure and fluid balance in the body. How ACE Inhibitors Work:
ACE inhibitors work by inhibiting the activity of the angiotensin converting enzyme (ACE), which prevents the conversion of angiotensin I to angiotensin II. By doing so, ACE inhibitors reduce the levels of angiotensin II in the body.
Explanation: The RAAS pathway involves several steps:
Renin Secretion: When blood pressure drops or sodium levels decrease, the kidneys release an enzyme called renin.
Conversion of Angiotensinogen to Angiotensin I: Renin acts on a protein called angiotensinogen, which is produced by the liver, to convert it into angiotensin I.
Angiotensin I to Angiotensin II Conversion: Angiotensin I is then further converted into angiotensin II by an enzyme called angiotensin converting enzyme (ACE). This conversion mainly occurs in the lungs.
Effects of Angiotensin II: Angiotensin II is a potent vasoconstrictor, which means it causes blood vessels to constrict, leading to increased blood pressure. It also stimulates the release of aldosterone from the adrenal glands, promoting sodium and water retention, which can further increase blood pressure.
How ACE Inhibitors Work:
ACE inhibitors work by inhibiting the activity of the angiotensin converting enzyme (ACE), which prevents the conversion of angiotensin I to angiotensin II. By doing so, ACE inhibitors reduce the levels of angiotensin II in the body. This leads to several beneficial effects:
Vasodilation: With reduced levels of angiotensin II, blood vessels relax and dilate. This results in decreased resistance to blood flow and lower blood pressure.
Reduced Aldosterone Release: Since angiotensin II is responsible for stimulating aldosterone release, ACE inhibitors also lead to reduced levels of aldosterone. This prevents excessive sodium and water retention, which contributes to lowering blood pressure and decreasing the workload on the heart.
Inhibition of Vasoconstriction: By inhibiting angiotensin II, ACE inhibitors prevent the potent vasoconstrictor effects of this peptide, further contributing to blood pressure reduction."