Study of the protective effect of calcium channel blockers against neuronal damage induced by glutamate in cultured hippocampal neurons

Background: the aim of this study was to examine the putative protective effect of calcium channel blockers on hippocampal neurons in the experimental model of excitotoxic damage. methods: seven-day old primary dissociated cultures of rat hippocampal neural cells containing one of the following calcium channel blockers: cinnarizine,flunarizine or nimodipine were exposed to glutamate-induced injury. quantitative assessments of neuronal injury were accomplished by measuring lactate dehydrogenase (ldh) activity in the media 24 h after exposure to glutamate and by counting and establishing the apoptotic and necrotic cells in flow cytometry with annexin v-fitc/pi staining. results: in our experiment,glutamate induced a 339% elevation of apoptotic cells and a 289% increase of necrotic cells in hippocampal neurons as compared to control cultures without drugs. in cultures containing flunarizine,glutamate-induced cell apoptosis was suppressed by 62% while necrosis showed no significant alternation. cinnarizine exerted no anti-apoptotic effects on glutamate-injured cultured hippocampal neurons,while nimodipine intensified the apoptotic pathway of cell death and promoted an increase in the number of apoptotic neurons by 26%. when cinnarizine or nimodipine were used,the percentage of necrotic cells was significantly lower when compared with glutamate-injured cultures and it amounted to 44% and 24% for cinnarizine and nimodipine,respectively. conclusions: the obtained results suggest the beneficial anti-apoptotic potential of flunarizine and the anti-necrotic potential of cinnarizine against glutamate-induced death of cultured hippocampal neurons. nimodipine can protect neurons against necrosis,but has an intensified adverse pro-apoptotic effect on cultured neurons in the experimental model of excitotoxic injury. copyright © 2013 by institute of pharmacology polish academy of sciences.