AIM To study if non cholinergic mechanism is involved in the antagonism of
phencynonate against soman induced seizure.
METHODS Rats were received soman 180 μg·kg -1 sc, different doses of atropine, scopolamine or
phencynonate were administrated in different times(5, 20 and 40 min) after the soman induced seizure onset. Mice were injected atropine(1, 5, 10, 20, 40, 60 mg·kg -1 ip), scopolamine(1, 5, 10, 20, 40, 60 mg·kg -1 ip) or phencynonate(1, 4, 8, 16 mg·kg -1 ip)30 min before received convulsant doses of
pentylenetetrazol(95 mg·kg -1 sc) or lethal dose of N methyl D aspartate (NMDA 175 mg·kg -1 ip) . RESULTS The anticonvulsant effects of atropine , scopolamine decreased along with the sustaining of seizure, and eventually lost their anticonvulsant activities if seizure had lasted for 40 min. In contrast, phencynonate showed a good anticonvulsant effectiveness at 5, 20 min, especially at 40 min after the seizure onset. Among the three drugs, only phencynonate 4, 8, 16 mg·kg -1 ip could control the pentylenetetrazol induced seizure and phencynonate, 4, 8, 12 mg·kg -1 ip could antagonize the lethal effects of NMDA in mice. CONCLUSION Being different from atropine and scopolamine, phencynonate can still afford protection in the later time of soman induced seizure; and it can also control the pentylenetetrazol induced seizure and antagonize the NMDA induced letha lity.