Regulation of Cl- channels in normal and cystic fibrosis airway epithelial cells by extracellular ATP.
AUTOR(ES)
Stutts, M J
RESUMO
The rate of Cl- secretion by human airway epithelium is determined, in part, by apical cell membrane Cl- conductance. In cystic fibrosis airway epithelia, defective regulation of Cl- conductance decreases the capability to secrete Cl-. Here we report that extracytosolic ATP in the luminal bath of cultured human airway epithelia increased transepithelial Cl- secretion and apical membrane Cl- permeability. Single-channel studies in excised membrane patches revealed that ATP increased the open probability of outward rectifying Cl- channels. The latter effect occurs through a receptor mechanism that requires no identified soluble second messengers and is insensitive to probes of G protein function. These results demonstrate a mode of regulation of anion channels by binding ATP at the extracellular surface. Regulation of Cl- conductance by external ATP is preserved in cystic fibrosis airway epithelia.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=48504Documentos Relacionados
- Activation of normal and cystic fibrosis Cl- channels by voltage, temperature, and trypsin.
- Ketoconazole activates Cl- conductance and blocks Cl- and fluid absorption by cultured cystic fibrosis (CFPAC-1) cells.
- Cystic fibrosis gene expression is not correlated with rectifying Cl- channels.
- Tolbutamide causes open channel blockade of cystic fibrosis transmembrane conductance regulator Cl- channels.
- Chloride uptake into cultured airway epithelial cells from cystic fibrosis patients and normal individuals.