Regulation of intracellular pH in avian renal proximal tubules

Yung Kyu Kim, Olga H. Brokl, William H. Dantzler

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

In proximal tubules isolated from chicken transitional nephrons, intracellular pH (pH(i)), measured with the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5,6 carboxyfluorescein (BCECF), was -7.3-7.4 under control conditions [N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid- buffered medium with pH 7.4 at 39°C] and was reduced to ~6.8 in response to NH4Cl pulse. The rate of recovery of pH(i) (dpH(i)/dt) from this acid level to the resting level and the resting pH(i) were 1) significantly reduced by the removal of Na+ from the bath, 2) significantly increased by the removal of Cl- from the bath, and 3) unchanged by the removal of both Na+ and Cl- from the bath. The addition of either amiloride or 4,4'- diisothiocyanostilbene-2,2'-disulfonate to the both reduced dpH(i)/dt to about the same extent as the removal of Na+. These data suggest that both Na+-coupled and Cl--coupled acid-base fluxes at the basolateral membrane are involved in determining the resting phi and the rate of recovery of phi after acidification. The most likely possibilities appear to be a basolateral Na+/H+ exchanger, a basolateral Na+-coupled Cl-/HCO3 exchanger, a basolateral Na+-HCO3-CO3/2+ cotransporter, and a basolateral Na+- independent Cl-/HCO3 exchanger.

Original languageEnglish (US)
Pages (from-to)R341-R349
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume272
Issue number1 41-1
DOIs
StatePublished - 1997

Keywords

  • ammonium chloride pulse
  • chickens
  • chloride- coupled basolateral acid-base fluxes
  • intracellular acidification
  • intrinsic buffering capacity
  • sodium-coupled basolateral acid-base fluxes

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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