H(+)-K(+)-ATPase in rabbit cortical collecting duct B-type intercalated cell.
The role of H(+)-K(+)-adenosinetriphosphatase (H(+)-K(+)-ATPase) in the cortical collecting duct (CCD) B-type intercalated cell (B cell) is unclear. This study examined whether H(+)-K(+)-ATPase contributes to B cell intracellular pH (pHi) regulation and, if so, whether it is present at the apical or basolateral membrane. B cell Na(+)-independent pHi recovery from an acid load was only partially inhibited by peritubular N-ethylmaleimide (NEM). Complete inhibition required combining peritubular NEM either with luminal Sch-28080 or with luminal K+ removal. In contrast, neither peritubular Sch-28080 nor peritubular K+ removal altered pHi regulation. Tomato lectin, which binds to the gastric H(+)-K(+)-ATPase beta-subunit, labeled the B cell apical membrane. We conclude that the rabbit CCD B cell possesses an apical H(+)-K(+)-ATPase that plays an important role in pHi recovery from an in vitro acid load.
Weiner
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Division of Nephrology, Hypertension, and Transplantation, University of Florida College of Medicine, USA.
Milton
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D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D005260:Female; D017506:H(+)-K(+)-Exchanging ATPase / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007672:Kidney Cortex / Q000201:enzymology*; D007685:Kidney Tubules, Collecting / Q000201:enzymology*; D011817:Rabbits
D017506:H(+)-K(+)-Exchanging ATPase