To my current understanding, stenosis or narrowing of the arteries would mean higher blood pressure, similar to atherosclerosis. So the Renin system should be suppressed to counter the high blood pressure. But..
I have read in a textbook that renal artery stenosis means lower blood flow in the kidney due to the narrowing of the artery. Thus the Renin system is activated to increase blood pressure.
So why does narrowing of the renal artery cause a decrease in blood pressure, and not increase?