[Influence of phosphatidylcholine on the threshold dose of pentylenetetrazol for inducing seizure].

Because of its putative long-acting cholinomimetic property, phosphatidylcholine (Pc, lecithin), is expected to have a therapeutic efficacy on states in which a cholinergic hypofunction in the CNS is pathognomonic. Cholinomimetic drugs in general have been reported to enhance proconvulsive predisposition of animals in various experimental situations. In our experiments, however, neither incidences of spontaneous myoclonic jerks nor pentylenetetrazol (Ptz)-induced seizure was changed in Mongolian gerbils, 12 hr after 95% soybean Pc (755 mg/kg) pretreatment. The ED50's of Ptz in inducing tonic-clonic convulsion were 44.0 mg/kg for control group which was pretreated with vehicle alone and 42.3 mg/kg for Pc-pretreated group. Some recent observations on humans and animals pose a question concerning Pc's action through the central cholinergic transmission. These and our results indicate that further investigations using behavioral parameters of animals are necessary before establishing and characterizing the central action of Pc.