钾通道阻断剂对低氧／复氧诱导的培养海马神经元死亡的防护作用

Protection of potassium channel inhibitors against hypoxia/reoxygenation-induced death of cultured hippocampal neurons.

OBJECTIVE: To investigate the effects of potassium channel inhibitors on hypoxia/reoxygenation-induced death of cultured hippocampal neurons. METHODS: Cultured 8 d in vitro, hippocampal neurons were exposed to hypoxia (in mixture of 95% N2 and 5% CO2) for 6 h, and then reoxygenated till the 72nd hour. Different potassium channel inhibitors were applied to the culture solution separately after reoxygenation. Neuron death was analyzed with cell counting and MTT assay. RESULTS: Hypoxia/reoxygenation procedure induced a delayed death of cultured hippocampal neurons. Application of tetraethylammonium (TEA) offered concentration-dependent protection of the neurons against death. Selective high-conductance calcium-activated potassium channel (BK) inhibitor iberiotoxin (IbTX) showed significant neuron protection (P<0.001). However, A-type potassium channel inhibitor 4-aminopyridine presented no protection against neuron death (P>0.05). CONCLUSION: Following hypoxia/reoxygenation, enhanced activity of potassium channel, especially BK channel, may induce neuron death.