Effect of 5-hydroxytryptamine on bioelectric properties of airway epithelial cells in culture.
To elucidate whether 5-hydroxytryptamine (5-HT) affects airway epithelial electrolyte transport and, if so, what the mechanism of action is, we studied the bioelectric properties of canine cultured tracheal epithelium under short-circuit conditions in vitro. Mucosal addition of 5-HT dose-dependently increased short-circuit current (Isc), which was accompanied by increases in transepithelial potential difference and cell conductance. In contrast, 5-HT had no effect on bioelectric properties when it was added to the submucosal side. Pretreatment of cells with amiloride potentiated the increase in Isc produced by 5-HT. In the presence of diphenylamine-2-carboxylate or Cl-free medium, 5-HT decreased Isc from the baseline level. Incubation with BAPTA-AM but not dibutyryl cAMP greatly attenuated the 5-HT-induced increase in amiloride-insensitive portion of Isc. These results suggest that 5-HT inhibits Na absorption and stimulates Cl secretion across canine tracheal epithelium and that the Cl secretion may be associated with elevation of intracellular Ca2+ contents.
Tamaoki
J
J
First Department of Medicine, Tokyo Women's Medical College, Japan.
Chiyotani
A
A
Takemura
H
H
Konno
K
K
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D016085:Bronchoconstrictor Agents / Q000494:pharmacology*; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D016764:Cell Polarity; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D004285:Dogs; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D017097:Electric Impedance; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005260:Female; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects; D014132:Trachea / Q000166:cytology / Q000187:drug effects*
D016085:Bronchoconstrictor Agents; D002712:Chlorides; D015222:Sodium Channels; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D012701:Serotonin; D004533:Egtazic Acid; D003994:Bucladesine; D000584:Amiloride; D012964:Sodium; D002118:Calcium