الفهرس 
ACKNOWLEDGEMENT
Role of Ion channels in the pharmacological actions of drugsOnly 14 pages are availabe for public view
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Abstract
In the present work a trial was undertaken to investigate the role of ion channels in the mechanism of the antiepileptic activity of valproic acid. To achieve this goal the effect of three drugs, which modulate ion channels, on the anticonvulsant activity of this agent was studied. These drugs were nifedipine and verapamil as calcium channel blockers as well as lidocaine as sodium channel blocker. Anticonvulsant activity was determined after chemical induction of seizures by four different agents acting through various mechanisms simulating different types of epilepsy in humans.
These were: pentylenetetrazole, bicuculline, kainic acid and stJ.ychnine. Three parameters were studied after induction of seizures by these agents: onset of seizures, mean survival time and percent protection of animals from death. A comparison was set up between the single and combined anticonvulsant activity of valproic acid with the above mentioned ionic modulators. In another set of experiments, a comparison was made between the single effect of valproic acid on the serum and brain electrolyte ( Na+, K+ and Ca++ ) levels of mice and its concurrent effect with the other calcium and sodium blockers ( nifedipine, verapamil and lidocaine ).
Results of this investigation revealed that valproic acid produces effective protection of animals against the four types of chemically-induced seizures as reflected by a significant increase in the onset of seizure development, the percent of animals protected from death and the mean survival time of these animals. Valproic acid was more effective against pentylenetetrazole- and showed moderate activity against bicuculline- and kainic acid- and was less effective against stJ.ychnine-induced seizures.