Mechanisms of chloride transport in thymic lymphocytes

Donatas Stakisaitis, Michael S. Lapointe, Daniel Batlle*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

This study examined mechanisms of Cl- transport in rat lymphocytes under a variety of conditions. Basal intracellular Cl- concentration ([Cl-]i) was not different between cells assayed in the presence of HCO-3 or its absence (HEPES). Removal of external Cl- resulted in a fall in [Cl-]i and a rapid rise in intracellular pH (pHi). Both Cl- efflux and the rise in pHi were blocked by DIDS or removal of external Na+ but were unaffected by furosemide. The mechanisms governing Cl- influx were assessed in cells that had been Cl- depleted for 1 h. Reexposure to Cl- resulted in a rapid rise in [Cl-]i that was partially inhibited by pretreatment with DIDS (57%) and partially inhibited by pretreatment with furosemide (45%). Pretreatment with both compounds together completely blocked Cl- influx. Cl- depletion caused a marked increase in pHi that rapidly declined toward normal when the cells were reexposed to Cl-. Preincubation with DIDS completely blocked this decrease in pHi. In contrast, neither removal of Na+ nor preincubation with furosemide affected the decline in pHi when the cells were reexposed to Cl-. We conclude that, in thymic lymphocytes, Cl-HCO-3 (or Cl-/base exchange) regulates both Cl- influx and efflux. Cl- efflux is totally inhibited by DIDS and is mediated by a Na+-dependent Cl-/HCO-3 exchanger. Cl- influx is partially DIDS sensitive and partially furosemide sensitive and is mediated by both a Na+-independent Cl-/HCO-3 exchanger and by a Na+-K+-2Cl- cotransporter.

Original languageEnglish (US)
Pages (from-to)F314-F324
JournalAmerican Journal of Physiology - Renal Physiology
Volume280
Issue number2 49-2
DOIs
StatePublished - Feb 2001

Keywords

  • 4,4′-diisothiocyanostilbene-2,2 ′-disulfonic acid
  • Chloride/bicarbonate exchange
  • Furosemide
  • Sodium-potassium-2 chloride cotransport
  • Stilbenes

ASJC Scopus subject areas

  • Physiology
  • Urology

Fingerprint Dive into the research topics of 'Mechanisms of chloride transport in thymic lymphocytes'. Together they form a unique fingerprint.

Cite this