Inhibitory action of haloperidol, spiperone and SCH23390 on calcium currents in rat retinal ganglion cells.
Patch-Clamp measurements in the whole-cell configuration were performed on isolated rat retinal ganglion cells to record voltage-activated calcium currents in the presence of dopamine antagonists. We report here that, in the absence of dopamine, application of the receptor antagonists haloperidol, spiperone and SCH23390 reduced calcium influx between 8% and 77%. The effect was fully reversible. After application of haloperidol and SCH23390, Ca2+ currents (ICa) recovered rapidly and completely within 30 s of washing. Current recovery after application of spiperone was completed only after 2 min of washing. I-V plots showed no change in the voltage-dependence of ICa during drug application. Also current kinetics remained unaffected by the dopamine antagonists.
Guenther
E
E
Department of Pathophysiology of Vision and Neuro-Ophthalmology, University Eye Hospital, Tübingen, Germany.
Wilsch
V
V
Zrenner
E
E
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects*; D002478:Cells, Cultured; D004298:Dopamine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology*; D015640:Ion Channel Gating / Q000187:drug effects; D018408:Patch-Clamp Techniques; D051381:Rats; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000502:physiology; D013134:Spiperone / Q000494:pharmacology*
D001552:Benzazepines; D015220:Calcium Channels; D013134:Spiperone; D006220:Haloperidol; D004298:Dopamine