Mechanisms of chloride transport in thymic lymphocytes
| Autor: | Donatas Stakisaitis, Daniel Batlle, Michael S. LaPointe |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Sodium-Potassium-Chloride Symporters
Physiology T-Lymphocytes Lymphocyte 4 4'-Diisothiocyanostilbene-2 2'-Disulfonic Acid Sodium Chloride Chloride Antiporters Rats Sprague-Dawley Basal (phylogenetics) Chlorides TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY medicine Animals Chloride-Bicarbonate Antiporters Anion exchanger Fluorescent Dyes Chemistry Quinolinium Compounds Hydrogen-Ion Concentration Fluoresceins Rats Cell biology Sprague dawley medicine.anatomical_structure Biochemistry Carrier Proteins Intracellular medicine.drug |
| Zdroj: | American Journal of Physiology-Renal Physiology. 280:F314-F324 |
| ISSN: | 1522-1466 1931-857X |
| DOI: | 10.1152/ajprenal.2001.280.2.f314 |
| Popis: | 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 HCO3−or its absence (HEPES). Removal of external Cl−resulted in a fall in [Cl−]iand a rapid rise in intracellular pH (pHi). Both Cl−efflux and the rise in pHiwere 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−]ithat 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 pHithat 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 pHiwhen the cells were reexposed to Cl−. We conclude that, in thymic lymphocytes, Cl−/HCO3−(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−/HCO3−exchanger. Cl−influx is partially DIDS sensitive and partially furosemide sensitive and is mediated by both a Na+-independent Cl−/HCO3−exchanger and by a Na+-K+-2Cl−cotransporter. |
| Databáze: | OpenAIRE |
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