Low-NaCl diet increases H-K-ATPase in intercalated cells from rat cortical collecting duct Academic Article uri icon

Overview

MeSH Major

  • Diet, Sodium-Restricted
  • H(+)-K(+)-Exchanging ATPase
  • Kidney Cortex
  • Kidney Tubules, Collecting
  • Macrolides

abstract

  • Extracellular K+-dependent H+ extrusion after an acute acid load, an index of H/K exchange, was monitored in intercalated cells (ICs) from rat cortical collecting tubule (CCT) using ratiometric fluorescence imaging of the intracellular pH (pHi) indicator, 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). The hypothesis tested was that 12- to 14-day NaCl deprivation increases H-K-ATPase in rat ICs. The rate of H/K exchange in the low-NaCl ICs was double that of controls. In control ICs, H/K exchange was inhibited by Sch-28080 (10 microM). In the low-NaCl ICs, it was partially blocked by Sch-28080 or ouabain (1 mM). Simultaneous addition of both inhibitors abolished K-dependent pHi recovery. The induced H/K exchange observed with NaCl restriction was not due to elevated plasma aldosterone as evidenced by experiments on ICs from rats implanted with osmotic minipumps administering aldosterone such that plasma levels were comparable to those of NaCl-deficient rats. The results suggest that NaCl deficiency induces two isoforms of H-K-ATPase in ICs and that this effect is not mediated by elevated plasma aldosterone.

publication date

  • July 1998

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed ID

  • 9689010

Additional Document Info

start page

  • F94

end page

  • 102

volume

  • 275

number

  • 1 44-1