Regan R F, Choi D W
Department of Surgery, Thomas Jefferson University, Philadelphia, PA 19107.
Brain Res. 1994 Jan 7;633(1-2):236-42. doi: 10.1016/0006-8993(94)91544-x.
A traumatic insult was delivered to murine cortical neuronal and glial cell cultures by tearing the cell layer with a stylet in a grid pattern. Consistent with prior observations, neurons adjacent to a tear developed immediate swelling, and then went on to degenerate over the next several hours. Delivery of multiple tears produced enough cell death that measurable levels of lactate dehydrogenase accumulated in the bathing medium 24 h later, correlating well with the extent of cell death as assessed by Trypan blue exclusion and cell counts. 50-75% of this trauma-induced cell death was blocked by the NMDA receptor antagonist MK-801. 10-100 microM CNQX also attenuated neuronal degeneration, but this neuroprotective effect was likely due to attenuation of NMDA receptor-mediated toxicity, since the more specific AMPA/kainate antagonist NBQX was ineffective. CNQX also did not augment the protective effect of MK-801. High concentrations of nimodipine or nifedipine produced modest neuroprotective effects; either dihydropyridine when combined with MK-801 reduced injury more than MK-801 alone. These results suggest that traumatic neuronal death in this in vitro model is mediated in part by excessive activation of NMDA receptors, and in part by mechanisms sensitive to high concentrations of dihydropyridines, but not by AMPA/kainate receptors.
通过用探针以网格模式撕裂细胞层，对小鼠皮质神经元和神经胶质细胞培养物造成创伤性损伤。与先前的观察结果一致，靠近撕裂处的神经元立即出现肿胀，然后在接下来的几个小时内逐渐退化。多次撕裂导致足够的细胞死亡，以至于24小时后在培养液中积累了可测量水平的乳酸脱氢酶，这与通过台盼蓝排斥法和细胞计数评估的细胞死亡程度密切相关。这种创伤诱导的细胞死亡的50 - 75%被NMDA受体拮抗剂MK - 801阻断。10 - 100微摩尔的CNQX也减轻了神经元的退化，但这种神经保护作用可能是由于NMDA受体介导的毒性减弱，因为更具特异性的AMPA/海人藻酸受体拮抗剂NBQX无效。CNQX也没有增强MK - 801的保护作用。高浓度的尼莫地平或硝苯地平产生适度的神经保护作用；当与MK - 801联合使用时，两种二氢吡啶类药物比单独使用MK - 801能更有效地减轻损伤。这些结果表明，在这个体外模型中，创伤性神经元死亡部分是由NMDA受体的过度激活介导的，部分是由对高浓度二氢吡啶敏感的机制介导的，而不是由AMPA/海人藻酸受体介导的。
