When proton pumps go sour: Urinary acidification and kidney stones.

H(+)-ATPases mediate urinary acidification along the collecting duct, and mutations in their B1 and a4 subunits result in distal renal tubular acidosis. The pathomechanisms by which these mutations affect pump activity are only poorly understood. Common polymorphisms may impair pump activity and may link the pump to a higher risk for alkaline urine and the development of kidney stones.