Basement 1) Renin-angiotension system membrane cells Toxin. Ischemia pairing proximal convoluted tube and ascending limb of medullary lope vasoconstriction Macula arteriole Reabsorption of na+↓ Renal perfusion pressure V Nat in distal convoluted tubeT (T-G feedback) ing Stimulating macula densa i Juxtaglomerular cells in afferent arteriole of juxtaglomerular apparatus Activating ras 2626 Impairing proximal convoluted tube and ascending limb of medullary lope stimulating juxtaglomerular cells in afferent arteriole 1) Renin-angiotension system Toxin , Ischemia Activating RAS Renal perfusion pressure  Stimulating macula densa of juxtaglomerular apparatus Reabsorption of Na+  vasoconstriction (T-G feedback) Na+ in distal convoluted tube