Which compound can cause impairment of renal autoregulation?

ACE inhibitors can impair renal autoregulation primarily through their action on the renin-angiotensin-aldosterone system. In normal physiology, the kidneys maintain a relatively constant blood flow and glomerular filtration rate (GFR) despite fluctuations in systemic blood pressure, a function known as renal autoregulation. This autoregulation is largely mediated by the ability of the afferent arterioles to dilate in response to decreased perfusion pressure, and the efferent arterioles can constrict under certain conditions to maintain GFR.

ACE inhibitors inhibit the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor that plays a significant role in maintaining efferent arteriolar tone. When the action of angiotensin II is blunted, especially in cases of renal artery stenosis or post-surgical scenarios, there may be insufficient constriction of the efferent arteriole. This can lead to a reduction in GFR, particularly when systemic blood pressure drops. Therefore, while ACE inhibitors are beneficial for treating conditions such as hypertension and heart failure, they can compromise renal blood flow and autoregulation in certain populations, making renal function more sensitive to changes in systemic perfusion.

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