Effect of Nicardipine on Cell Death Caused by Zinc in the Rat Hippocampus

Abstract

There are lots of reports about zinc causes cell death due to neuronal hyperactivity. In this study, effect of nicardipine (a calcium antagonist) on cell death caused by zinc was investigated. Zinc sulphate (500 μg/kg) was injected intracortically into 2 mm lateral of bregma. The same of volume of saline (2 μl) was given to the rats of control group. In the third group, zinc + nicardipine were injected into same place of the brain. Animal groups were observed for a week. The zinc + nicardipine group received daily nicardipine (10 mg/kg) for seven days. After a week, the rats were perfused intracardially with neutral formaline. The hippocampal sections were stained with hematoxylen-eosine. Pyramidal cells were counted under light microscope (with 400x magnification). The density of pyramidal cell was found in the control, zinc and zinc + nicardipine as 126.48 ± 1.8 neuron/mm, 38.3 ± 0.52 neuron/mm, 88.4 ± 1.4 neuron/mm respectively. The differences between the groups were found to be statistically significant (p < 0.001). The results show that nicardipine considerably decreases cell death caused by zinc in the hippocampus of rat. Nicardipine an exert this effect by preventing the influx of calcium.