Vinpocetine is as potent as phenytoin to block voltage-gated Na+ channels in rat cortical neurons.
The effects of vinpocetine and phenytoin on voltage-gated Na+ channels were examined on cultured cerebrocortical neurones of the rat using a conventional whole-cell patch-clamp method. Vinpocetine and phenytoin decreased Na+ currents in a concentration-dependent manner, with IC50 values of 44.2 +/- 14.6 and 50.5 +/- 17.4 microM, respectively. Both compounds shifted the voltage dependence of the steady-state inactivation of the channel in the hyperpolarising direction. This pronounced Na+ channel blocking activity may contribute to the neuroprotective and anticonvulsant effects of vinpocetine.
Molnár
P
P
CNS Pharmacology Laboratory, Chinoin Co. Ltd., Budapest, Hungary.
Erdö
S L
SL
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004594:Electrophysiology; D015640:Ion Channel Gating / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010672:Phenytoin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000187:drug effects*; D014748:Vinca Alkaloids / Q000494:pharmacology*
D000927:Anticonvulsants; D015222:Sodium Channels; D014748:Vinca Alkaloids; C013983:vinpocetine; D010672:Phenytoin