title: Serotonin activates Cl- channels in the apical membrane of rat choroid plexus epithelial cells.
abstract: The effects of serotonin on ion channel activity in epithelial cells from rat choroid plexus were examined. Serotonin (50 nM, 500 nM and 1 microM) stimulated channel activity in cell-attached patches. The current-voltage (I-V) relationship for the serotonin-activated channel gave a conductance of 26.6 +/- 1.5 pS and the current reversed at an applied electrode potential (-Vp) = 15.3 +/- 3.3 mV with a KCl-rich electrode solution (n = 8). Similar I-V relationships were obtained using electrode solutions in which K+ was replaced by other cations (Na+ and N-methyl-D-glucamine), suggesting that the serotonin-activated channels are selective to Cl-. The effect of 1 microM serotonin on channel activity was inhibited by ritanserin (30 and 100 nM) which has a high affinity for serotonin 5-HT1C receptors and 5-HT2 receptors. Spiperone (30 nM), which binds weakly to 5-HT1C receptors but has a high affinity for 5-HT2 receptors, did not inhibit the actions of serotonin. These data suggest that serotonin increases Cl- channel activity by acting on the 5-HT1C receptors on the epithelium.
authors.affiliation: Department of Physiological Sciences, University of Manchester, UK.
authors.forename: C
authors.initials: C
authors.lastname: Garner
authors.forename: W
authors.initials: W
authors.lastname: Feniuk
authors.forename: P D
authors.initials: PD
authors.lastname: Brown
mesh_terms: D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000187:drug effects; D018118:Chloride Channels / Q000187:drug effects*; D002831:Choroid Plexus / Q000166:cytology / Q000187:drug effects*; D004347:Drug Interactions; D004594:Electrophysiology; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005260:Female; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism; D016713:Ritanserin / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D018118:Chloride Channels; D011985:Receptors, Serotonin; D016713:Ritanserin; D012701:Serotonin