Ejection of intracellular H in exchange for external Na is the most effective means of
eliminating excess acid from actively metabolizing cells. Na/H exchange is also crucial for
the regulation of the cellular volume and for the reabsorption of NaCl across renal, intestinal,
and other epithelia. This remarkable array of essential functions is carried out by a family of
antiporters, known generically as Na/H exchangers (NHEs). 1 These are highly regulated
(glyco) phosphoproteins present in virtually all mammalian tissues and species studied to …