Extracellular 2-chloroadenosine and ATP stimulate volume-sensitive Cl- current and calcium mobilization in human tracheal 9HTEo- cells.
The perforated-patch whole-cell technique was used to record membrane currents in epithelial cells (9HTEo-) obtained from the human tracheal epithelium. Extracellular application of 2-chloroadenosine and ATP (0.01-100 microM) caused activation of Cl- currents similar to those regulated by cell volume in airway and intestinal cells. This response was inhibited by increasing extracellular osmolality, by omission of extracellular Ca2+, or by the addition of the A2 adenosine receptor antagonist 3,7-dimethyl-1-propargylxanthine (DMPX). Fluorimetric measurements with fura-2 reveal that 2-chloroadenosine and ATP elicited both a Ca2+ influx through the plasma membrane and a release from intracellular stores.
Galietta
L J
LJ
Laboratorio di Genetica Molecolare, Ist. G. Gaslini, Genova, Italy.
Rasola
A
A
Rugolo
M
M
Zottini
M
M
Mastrocola
T
T
Gruenert
D C
DC
Romeo
G
G
D015762:2-Chloroadenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D016257:Fura-2; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000378:metabolism*; D013805:Theobromine / Q000031:analogs & derivatives / Q000494:pharmacology; D014132:Trachea / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
D018118:Chloride Channels; D002712:Chlorides; D007473:Ion Channels; D008565:Membrane Proteins; D015762:2-Chloroadenosine; C057837:3,7-dimethyl-1-propargylxanthine; D000255:Adenosine Triphosphate; D013805:Theobromine; D002118:Calcium; D016257:Fura-2