Cortical malformation-associated epileptic seizures are resistant to conventional anticonvulsant drugs. Relatively little research has been conducted on the effects of antiepileptic drugs (AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate (MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of ethosuximide (ETX) in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injected control animals. Field potential recordings were used to monitor the amplitude and number of population spikes, and paired pulse inhibition in response to stimulation of the commissural pathway. Pharmaco-resistance was tested by measuring seizure latencies after pilocarpine administration (320 mg/kg, i.p.) with and without pre-treatment with ETX. Pre-treatment with 300 mg of ETX significantly prolonged the latency to the status epilepticus (SE) in both control and MAM-treated groups. Pre-treatment with ETX 100mg and ETX 200 mg had little effect in MAM-exposed rats. However, ETX 200 mg prolonged the latency to the SE in control groups. Spontaneous field potential and secondary after-discharges were higher for MAM-treated rat in comparison with control rats injects with ETX. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard ETX assessed in vivo. These data suggest that ETX do not prolong seizure latencies in MAM-rats exposed to pilocarpine.
Animals ; Anticonvulsants ; Brain ; Epilepsy ; Ethosuximide* ; Methylazoxymethanol Acetate ; Models, Animal* ; Neuronal Migration Disorders* ; Neurons* ; Pilocarpine* ; Rats* ; Seizures* ; Status Epilepticus

OBJECTIVETo develop a RP-HPLC method for the determination of the content of macrozamin in Rhizoma Heterosmilacis Japonicae.

METHODA Century C18 AQ column (4.6 mm x 250 mm, 5 microm) was used with the mobile phase consisted of water (4:96). The flow rate was 1.0 mL x min(-1). The detection wavelength was set at 215 nm, and the column temperature was 35 degrees C.

RESULTThe calibration curve was linear (r = 0.999 8) in the range of 19.12 - 382.4 microg x mL(-1) for macrozamin, the average recovery of the method was 99.5%, with RSD 2.1% (n = 9).

CONCLUSIONThis method can be used for the quality study of Rhizoma Heterosmilacis Japonicae.

Chromatography, High Pressure Liquid ; methods ; Liliaceae ; chemistry ; Methylazoxymethanol Acetate ; analogs & derivatives ; analysis ; Plants, Medicinal ; chemistry ; Reproducibility of Results ; Rhizome ; chemistry