thus urea infusion ( 1 ) inhibits reabsorption of sodium , potassium , and calcium proportionately more than of magnesium in the proximal tubule , ( 2 ) inhibits sodium , calcium , and magnesium reabsorption in the loop , ( 3 ) promotes potassium secretion into the pars recta of descending limb in the loop of henle , ( 4 ) has little effect on ion transport beyond the distal sampling site , and ( 5 ) causes a slight phosphaturia at both levels of urea infusion by inhibiting proximal phosphate reabsorption .
C0360641
calcium
C0006675
calcium