Effect of benidipine on depolarizing stimulation-induced increase of intracellular calcium concentration in cultured mouse hippocampal neurons

We examined the effect of benidipine, a 1,4-dihydropyridine calcium channel blocker, on depolarizing stimulation-induced increases of intracellular calcium concentration ([Ca2+](i)) in cultured mouse hippocampal neurons in comparison with those of nicardipine and nilvadipine. Benidipine (0.1-10 mu M) inhibited the [Ca2+](i) increase compared with the no drug control response. This effect was stronger than those of nicardipine and nilvadipine. The inhibitory effect of benidipine lasted even after washing out the drug for 125 min, while those of nicardipine and nilvadipine disappeared more rapidly. This is the first report that demonstrates that benidipine inhibits the [Ca2+](i) increase in the neuron itself.