How do ARBs (angiotensin II receptor blockers) function in the body?

Angiotensin II receptor blockers (ARBs) function by blocking the action of angiotensin II at specific receptor sites. Angiotensin II is a potent vasoconstrictor that plays a significant role in regulating blood pressure and fluid balance in the body. By inhibiting its action, ARBs lead to vasodilation, which decreases blood pressure. This mechanism reduces the overall workload on the heart and improves blood flow.

The effectiveness of ARBs in managing hypertension and heart failure is due to their ability to disrupt the renin-angiotensin-aldosterone system (RAAS), which is crucial in fluid and electrolyte balance. When angiotensin II's effects are prevented, there is a decrease in blood vessel constriction, a reduction in aldosterone secretion (which typically promotes sodium retention), and ultimately, a decrease in blood pressure.

Understanding the role of angiotensin II and the function of ARBs is essential for utilizing these medications effectively in the treatment of hypertension and other cardiovascular conditions.