Phenytoin reduces early acetylcholine release after depolarization.
Phenytoin 10 microM inhibits the K-evoked release of acetylcholine (ACh) from synaptosomes, a process which is biphasic. Phenytoin acts only on the early phase of release. Replacement of external Na with Li does not modify phenytoin's effect. Phenytoin augments the spontaneous release of ACh from resting synaptosomes but this effect is eliminated in Li media. It is likely that phenytoin reduces K-evoked Ca uptake and the Na/Ca exchange by separate mechanisms.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002712:Chlorides / Q000494:pharmacology; D066298:In Vitro Techniques; D008094:Lithium / Q000494:pharmacology; D018021:Lithium Chloride; D008564:Membrane Potentials / Q000187:drug effects; D010672:Phenytoin / Q000494:pharmacology*; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
D002712:Chlorides; D010672:Phenytoin; D008094:Lithium; D018021:Lithium Chloride; D000109:Acetylcholine