Separate taurine and chloride efflux pathways activated during regulatory volume decrease
Stutzin, A.; Torres, R.; Oporto, M.; Pacheco, P.; Eguiguren, A.L.; Cid, L.P.; Sepúlveda, F.V.
American Journal of Physiology 277(3): C392-C402
1999
ISSN/ISBN: 0002-9513 PMID: 10484326 Document Number: 498282
Organic osmolyte and halide permeability pathways activated in epithelial HeLa cells by cell swelling were studied by radiotracer efflux techniques and single-cell volume measurements. The replacement of extracellular Cl- by anions that are more permeant through the volume-activated Cl- channel, as indicated by electrophysiological measurements, significantly decreased taurine efflux. In the presence of less-permeant anions, an increase in taurine efflux was observed. Simultaneous measurement of the 125I, used as a tracer for Cl-, and 4 min after triggering cell swelling. This taurine-induced effect was blocked by DIDS. Differences in anion sensitivity, the time course of activation, and sensitivity to DIDS suggest that the main cell swelling-activated permeability pathways for taurine and Cl- are separate. Reprinted by permission of the publisher.