The inhibitory effect of nilvadipine on calcium channels in retinal ganglion cells in goldfish.
OBJECTIVE
Our aim was to examine the inhibitory effect of nilvadipine on voltage-gated calcium (Ca) channels in solitary ganglion cells.


METHODS
Eyes were excised from goldfish. Ganglion cells were enzymatically dissociated from isolated retina. Whole-cell currents were recorded with the perforated-patch clamp technique.


RESULTS
Depolarizing step pulses to more than -48 mV evoked a slowly inactivating inward Ca current. The current-voltage relation for the nilvadipine-sensitive current was bellshaped, and the peak current reached a maximum at -8 mV in the presence and absence of nilvadipine. Nilvadipine block of voltage-gated Ca current was dose-dependent between 1 and 100 microM. The half-maximum inhibitory dose was 35 microM.


CONCLUSIONS
The inhibitory effect of orally administered nilvadipine on Ca channels had a mild influence in ganglion cells.
Sasaki
Tsugihisa
T
Department of Ophthalmology, Kanazawa University School of Medicine, Kanazawa, Japan. sasatsug@w5.dion.ne.jp
Nakatani
Yuusuke
Y
Sugiyama
Kazuhisa
K
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006054:Goldfish; D066298:In Vitro Techniques; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000378:metabolism
D002121:Calcium Channel Blockers; D015220:Calcium Channels; C035100:nilvadipine; D009543:Nifedipine