L-type Ca2+ channel blocker attenuates impairment induced by acidosis in hippocampal neurons.

Accumulation of acid in the brain during ischemia may contribute to the activation of voltage-gated Ca2+ channels and subsequent neuronal injury. However, information regarding the role of L-type Ca2+ channel under acidosis remains unclear. In the present study, we examined the role of L-type Ca2+ channel in acidosis induced neuronal death and subsequent pathogenesis events responsible for neuron degeneration. Here we report that preincubation of cells with nifedipine (5 microM, 10 microM), an inhibitor of L-type Ca2+ channel markedly reduced neuronal death induced by moderate extracellular acidosis (pH 6.5) on cultured hippocampus neurons. Furthermore, nifedipine decreased the hippocampus neuronal swelling, as well as the accumulation of Ca2+ and collapse of mitochondrial membrane potential induced by acidosis. These findings demonstrate that pharmacological inhibition of L-type Ca2+ channel would attenuate neuronal degeneration caused by toxic low pH exposure in rat hippocampus neuron.