Which statement best explains how ACE inhibitors slow kidney disease progression in proteinuric disease?

• A. They reduce efferent arteriolar constriction, lowering intraglomerular pressure and decreasing proteinuria.
• B. They dilate afferent arteriole increasing GFR.
• C. They directly dissolve tubulointerstitial deposits.
• D. They have no effect on proteinuria.

Answer: (A)

The main idea is that ACE inhibitors slow kidney disease progression by changing how pressure is managed inside the glomerulus. Angiotensin II normally constricts the efferent arteriole, which raises intraglomerular pressure and increases the amount of protein filtered into the urine. Blocking angiotensin II formation with an ACE inhibitor lets the efferent arteriole relax, lowering intraglomerular pressure and reducing proteinuria. With less protein leaking into the tubules, there’s less ongoing tubulointerstitial injury and inflammation, slowing the progression of nephropathy. They don’t dissolve deposits or primarily affect the afferent arteriole, so the protective effect comes from reduced efferent arteriolar constriction and the consequent drop in glomerular pressure and proteinuria.