Effect of Zinc on brain GABAergic system Activity in animal model of seizure induced in Rat

In epileptic patients, seizure and behavioral disorders are the most important signs; therefore evaluation of these disorders using animal model can be conducive to advantage. Detetmination of the role of zinc in seizure and the relation of zinc concentrations in serum and hippocampus may be beneficial in developing preventive and therapeutic measures for epilepsy. The main purpose of this study was to evaluate the effect of zinc on seizure and its relation with GABAergic system activity. This was a prospective, empirical and blind study. 48 adult male Sprauge-Dawley rats were randomly assigned in six groups (n=8). 3 groups were treated with zinc and other 3 groups with tap water. Epileptic model was induced by injection of Lithium chloride (127mg/kg) and 24 hr later, pilocarpin (50 mg/kg) into peritoneum. After first injection, group 1 and 4 received saline, group 2 and 5 bicuculine (1 mg/kg) and group 3 and 6 pentobarbital (10mg/kg) injections. Episodes of seizure disorders were recorded at 1 and 2 hrs after injection. The results of this study showed that Zn had a potentiating effect on seizure. GABA A antagonists had the same effect as Zn on seizure but GABA A agonists ameliorate it significantly. Serum zinc level didnt change significantly among the animals but hippocampus zinc declined significantly in Zn treated animals compared with those of the controls. This study shows that Zn deleterious effects on seizure were probably carried out via GABAergic system.