米诺环素对大鼠原代神经元和海马脑片缺氧缺糖及NMDA损伤的保护作用

目的:建立神经元和海马脑片缺氧缺糖(OGD)及N-甲基-D-门冬氨酸(NMDA)损伤模型,观察抗炎药米诺环素的神经元保护作用及其特点.方法:体外培养大鼠脑皮层神经元,以OGD和NMDA(50 μmol/L)处理,观察损伤前后神经元形态变化,并以MTT检测神经元活性;以透光法检测OGD和NMDA处理引起的大鼠海马脑片透光度(LT)改变;在上述模型中同时观察米诺环素及NMDA受体拮抗剂MK-801的作用.结果:在OGD过程中米诺环素1、10 μmol/L能浓度依赖地提高神经元的活性,改善神经元形态改变;米诺环素10、100 μmol/L对NMDA损伤有保护作用;MK-801 1 μmol/L对两种损伤模型均有保护作用.米诺环素1或10 μmol/L对OGD和NMDA引起的海马脑片LT增加无明显影响;MK-801 1 μmol/L则能显著抑制LT增加.结论:米诺环素对神经元OGD损伤具有保护作用,可能是通过对NMDA受体介导的兴奋性毒性的间接抑制;但对海马脑片OGD和NMDA即刻损伤无保护作用.

Protective effect of minocycline on oxygen/glucose deprivation and NMDA-induced neurotoxicity in rat primary neurons and hippocampal slices

OBJECTIVE: To develop oxygen/glucose deprivation (OGD)-and NMDA-induced neurotoxicity models in rat primary neurons and hippocampal slices, and to determine the protective effect of minocycline. METHODS: The injuries of primary neurons were induced by OGD or NMDA (50micromol/L). Morphological changes of neurons were observed, and neuron viability was evaluated by MTT assay. The changes of light transmittance (LT) were induced by OGD or NMDA in rat hippocampal slices. The effects of minocycline and MK-801, an NMDA receptor antagonist, were observed in the models of OGD-or NMDA-induced injuries. RESULT: Minocycline concentration dependently inhibited OGD induced decrease of neuron viability and ameliorated neuron morphological changes at 1 and 10 micromol/L. It also inhibited NMDA insult at 10 and 100 micromol/L. MK-801 inhibited both injuries at 1 micromol/L. However, minocycline at 1 or 10 micromol/L did not inhibit the augment of LT in hippocampal slices induced by OGD or NMDA, while MK-801 inhibited both OGD-and NMDA-induced LT augments. CONCLUSION: Minocycline protects neurons from OGD insult, which may inhibit NMDA receptor-mediated neurotoxicity through an indirect pathway, but has no effect on OGD-or NMDA-induced immediate injury in hippocampal slices.