A number of recent papers have related an increased concentration of brain cyclic nucleotide to seizure susceptibility in various experimental models of epilepsy. However, Akiyama has recently found a significant decrease in CSF cAMP and cGMP in amygdaloid kindled cats, and stressed an inhibitory role of cyclic nucleotides on seizure susceptibility. During a series of such experiment, we found that probenecid (150 mg/kg) frequently induced generalized convulsions in the kindled cats. Behavioral, electrographic observation and measurement of CSF cyclic nucleotides were made in this study. The following results were obtained. Probenecid (150 mg/kg, i.p.) induced generalized convulsions more frequently in the kindled group (3 of 4 cats) than the control group (2 of 8 cats). Tonic, tonic-clonic generalized seizure appeared 30-60 minutes after the injection, and was easily triggered by external stimuli (i.e., loud sound, touch). dose dependent increase in interictal spike discharges was observed only in the kindled cats. CSF cGMP concentration was significantly higher in the cats without induced-convulsion than the cats with convulsions, while no difference was found in CSF cAMP concentration (at 60 minutes after the probenecid injection). And transfusion of cisternal CSF of the convulsed cats into the control cats induced no behavioral or electrographic change. These findings indicated a lower threshold for probenecid-induced convulsions in the kindled cats than the control cats. No relation was found between CSF cAMP and probenecid-induced convulsions.
|Number of pages||7|
|Journal||Brain and Nerve|
|Publication status||Published - Dec 1 1981|
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