Minor Role of Cl– Secretion in Non-Cystic Fibrosis and Cystic Fibrosis Human Nasal Epithelium
Na + and Cl – currents were studied in primary cultures of human nasal epithelium derived from non-cystic fibrosis (non-CF) and cystic fibrosis (CF) patients. We found that Na + absorption dominates transepithelial transport and the Na + current contains an amiloride-sensitive and amiloride-insensit...
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Veröffentlicht in: | Cellular physiology and biochemistry 1999-01, Vol.9 (1), p.1-10 |
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Sprache: | eng |
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Zusammenfassung: | Na + and Cl – currents were studied in primary cultures of human nasal epithelium derived from non-cystic fibrosis (non-CF) and cystic fibrosis (CF) patients. We found that Na + absorption dominates transepithelial transport and the Na + current contains an amiloride-sensitive and amiloride-insensitive component. In non-CF tissue both components contribute about equally to the entire short-circuit current (I SC ), whereas in CF tissues the major part of the current is amiloride-sensitive. Na + removal reduced I SC to values close to zero. Several Cl – channel blockers were used to identify the remaining tiny Na + -independent current. Under unstimulated, physiological conditions in the presence of Cl – on both sides and amiloride on the apical side of the epithelium diphenylamine-2-carboxic acid (DPC), 4,4′-diisothiocyanatostilbene-2,2′- disulfonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) failed to induce clearcut inhibition of I SC . cAMP as well as ATP did not affect I SC either in CF or in non-CF epithelia. Reduction of apical Cl – increased I SC and depolarized transepithelial potential; however, the observed increase was insensitive to DIDS, DPC and NPPB. From these data we conclude that Cl – conductances in primary cultures of human nasal epithelium derived from CF patients as well as from non-CF patients are present only in low numbers or do not contribute significantly to transepithelial ion transport. |
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ISSN: | 1015-8987 1421-9778 |
DOI: | 10.1159/000016298 |