Insensitivity of volume-sensitive chloride currents to chromones in human airway epithelial cells

Olga Zegarra-Moran, Sabina Lantero, Oliviero Sacco, Giovanni A. Rossi, Luis J V Galietta

Research output: Contribution to journalArticle

Abstract

1. Chromones (sodium cromoglycate and sodium nedocromil) block cell swelling-activated Cl- channels in NIH-3T3 fibroblasts and endothelial cells. This has led to hypothesize that cell volume regulation might be involved in asthma pathogenesis. 2. Using whole-cell patch-clamp experiments, we studied the effect of chromones on volume-sensitive Cl- currents in transformed human tracheal epithelial cells (9HTEo-) and in primary cultures of human bronchial epithelial cells (BE). 3. Cl- currents activated by hypotonic shock were poorly blocked by extracellular nedocromil or cromoglycate. The block was voltage-dependent since it was observed only at positive membrane potentials. At the concentration of 5 mM, the current inhibition by both chromones at +80 mV was about 40% for 9HYEo- and only 20% for BE. 4. Intracellular application of chromones elicited a voltage-independent inhibition in 9HTEo- cells. Under this condition, volume-sensitive Cl- currents were reduced at all membrane potentials (60 and 45% inhibition by 2 mM nedocromil and cromoglycate respectively). In contrast intracellular chromones were ineffective in BE cells. 5. The relative refractoriness to chromones, in contrast with the high sensitivity shown by other Cl-channels, suggests that the epithelial volume-sensitive Cl- channel is not involved in asthma.

Original languageEnglish
Pages (from-to)1382-1386
Number of pages5
JournalBritish Journal of Pharmacology
Volume125
Issue number6
Publication statusPublished - 1998

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Keywords

  • Airway epithelium
  • Asthma
  • Cell volume regulation
  • Cl currents
  • Nedocromil sodium
  • Sodium cromoglygate

ASJC Scopus subject areas

  • Pharmacology

Cite this

Zegarra-Moran, O., Lantero, S., Sacco, O., Rossi, G. A., & Galietta, L. J. V. (1998). Insensitivity of volume-sensitive chloride currents to chromones in human airway epithelial cells. British Journal of Pharmacology, 125(6), 1382-1386.