Animals 6 Vacuolar Proton-Translocating ATPases bafilomycin 6 proton transporting adenosine triphosphatase 6 Aging 4 Amiloride 4 Bicarbonates 4 Blotting, Western 4 Hydrogen-Ion Concentration 4 Kidney 4 Kidney Tubules, Proximal 4 Micropuncture experiments 4 Microvilli 4 Na+/H+ exchange 4 Rats 4 Sodium Channel Blockers 4 Sodium-Hydrogen Antiporter 4 V-H+-ATPase 4 Western blot 4 Western blotting 4 aged 4 amiloride derivative 4 animal cell 4 animal experiment 4 animal model 4 animal tissue 4 article 4 bicarbonate 4 cell isolation 4 controlled study 4