[Role of Na+/Ca2+ exchange blocker in rat hippocampal injury during anoxia].

Effects of Na+/Ca2+ exchange blocker, Benzamil, on rat hippocampal slices and on cultured hippocampal neuronal [Ca2+]i (intracellular free Ca2+ concentration) during anoxia were investigated by means of microelectrode recording technique and laser scanning confocal microscope respectively. The results showed that the PV sustained time of hippocampal slices pretreated with Benzamil (50 mumol) after anoxia was markedly longer than that of control, suggesting that inhibition of Na+/Ca2+ exchange can delay the irreversible injury to hippocampal cells. Moreover, by using a confocal microscope we found that acute anoxia induced a rapid increase of [Ca2+]i in hippocampal neurons and this could be significantly attenuated by 20 mumol Benzamil. All these results indicate that Na+/Ca2+ exchanger is involved in the anoxic injury to rat hippocampus and it may be one of the major ways leading to the anoxia-induced [Ca2+]i increase of hippocampal neurons.