| Autor: |
Thomas, Emma J., Martsen, Elena, Gabriel, Sherif E., Makhlina, Mariya, Boucher, Richard C., Lethem, Mike I. |
| Jazyk: |
angličtina |
| Rok vydání: |
2000 |
| DOI: |
10.17615/n8z0-gh70 |
| Popis: |
Calcium-activated Cl(-) secretion is an important modulator of regulated ion transport in murine airway epithelium and is mediated by an unidentified Ca(2+)-stimulated Cl(-) channel. We have transfected immortalized murine tracheal epithelial cells with the cDNA encoding the permeabilizing P2X(7) purinoreceptor (P2X(7)-R) to selectively permeabilize the basolateral membrane and thereby isolate the apical membrane Ca(2+)-activated Cl(-) current. In P2X(7)-R-permeabilized cells, we have demonstrated that UTP stimulates a Cl(-) current across the apical membrane of CF and normal murine tracheal epithelial cells. The magnitude of the UTP-stimulated current was significantly greater in CF than in normal cells. Ion substitution studies demonstrated that the current exhibited a permselectivity sequence of Cl(-) > I(-) > Br(-) > gluconate(-). We have also determined a rank order of potency for putative Cl(-) channel blockers: niflumic acid > or = 5-nitro-2-(3-phenylpropylamino)benzoic acid > 4, 4'-diisothiocyanostilbene-2,2'-disulfonate > glybenclamide >> diphenlyamine-2-carboxylate, tamoxifen, and p-tetra-sulfonato-tetra-methoxy-calix[4]arene. Complete characterization of this current and the corresponding single channel properties could lead to the development of a new therapy to correct the defective airway surface liquid in cystic fibrosis patients. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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