Final answer:
ACE inhibitors primarily function to lower systemic blood pressure and preserve kidney function by inhibiting the conversion of angiotensin I to angiotensin II, thus reducing vasoconstriction and aldosterone production.
Step-by-step explanation:
The main function of Angiotensin-Converting Enzyme inhibitors (ACE inhibitors or ACE-Is) is to regulate systemic blood pressure and kidney function. These medications are commonly prescribed to lower high blood pressure. ACE is not a hormone; it is produced in the lungs and is associated with endothelial cells within the kidneys.
By inhibiting ACE, these inhibitors reduce the conversion of angiotensin I to the potent vasoconstrictor angiotensin II, which in turn reduces vasoconstriction, decreases the production of aldosterone, and subsequently lowers blood pressure and preserves kidney function by reducing the glomerular filtration rate (GFR) during blood loss or dehydration.