Respuesta :
Answer:
Inhibiting conversion of angiotensin I to angiotensin II
Explanation:
RAAS
In the renin-angiotensin-aldosterone system (RAAS), the liver produces a protein called angiotensinogen in response to hypotension (low blood pressure), hyponatremia (low sodium levels), and or neurotransmitters that are signaling the sympathetic nervous system to trigger its fight-or-flight mechanisms. At this same time, the kidneys release a protein called renin which then results in the production of the hormone angiotensin I (or angiotensin 1). The lungs release angiotensin-converting enzyme (ACE) into the blood stream, thereby transitioning angiotensin I to angiotensin II.
This stimulates the adrenal glands atop the kidneys to secrete aldosterone, the kidneys to retain water in turn retaining sodium, the brain to increase thirst, and the blood vessels to vasoconstrict. All of this, subsequently, raises the blood pressure.
Captopril
Captopril is a medication belonging to a drug class known as angiotensin-converting enzyme (ACE) inhibitors. The function of this category of medications is to interrupt the RAAS system at the level of the lungs, blocking ACE from entering the bloodstream, thus blocking the conversion of angiotensin I to angiotensin II. Without this conversion, the RAAS system falls flat -- aldosterone levels decrease, renin may remain increased because it remains in the bloodstream, and the blood vessels vasodilate, thereby lowering the blood pressure. Because of this effect, captopril is used to treat hypertension, or elevated blood pressure where the patient's systolic reading is likely above 130 mmHg and their diastolic reading is possibly above 100 mmHg.
So in short, captopril, as an ACE inhibitor, stops the conversion of angiotensin 1 to angiotensin 2, blocking the RAAS from stimulating any of its intended effects.
Final answer:
Captopril inhibits the enzyme angiotensin-converting enzyme (ACE), leading to decreased levels of angiotensin II, which causes reduced vasoconstriction, lower aldosterone secretion, less sodium and water retention, and ultimately, a decrease in blood pressure and volume.
Explanation:
Captopril is a medication known as an ACE inhibitor that substantially affects the renin-angiotensin-aldosterone system (RAAS). By inhibiting the enzyme called angiotensin-converting enzyme (ACE), captopril reduces the conversion of angiotensin I to angiotensin II. As a result, there is a decrease in the levels of angiotensin II, which normally causes vasoconstriction and stimulates the release of aldosterone from the adrenal cortex. Consequently, captopril's action leads to a reduction in blood pressure, as the decreased levels of angiotensin II result in vasodilation and reduced vasoconstriction.
Furthermore, with lower aldosterone levels, there is less sodium reabsorption in the renal tubules, which leads to decreased blood volume and pressure. In addition, because aldosterone secretion is reduced, the system's usual effects of increasing blood volume and pressure are attenuated, and there is less retention of sodium and water. Overall, captopril's inhibition of ACE results in lowered systemic blood pressure and decreased blood volume.
