Ohmori T, Hirashima Y, Kurimoto M, Endo S, Takaku A
Department of Neurosurgery, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Brain Res. 1996 Dec 16;743(1-2):109-15. doi: 10.1016/s0006-8993(96)01034-7.
We prepared neuron-rich cultures from cortical and hippocampal CA1 regions of postnatal day 1 (P1) rats. Using these cultures, we investigated the sensitivity of neurons to hypoxic insults. The effects of MK-801, cycloheximide, NG-nitro-L-arginine (L-NNA), and anti-platelet-activating factor (anti-PAF) IgG on neuronal injury under hypoxic conditions also were examined. The percentage of astroglial cells was higher in CA1 than cortical cultures despite use of the same culture procedure. Despite this finding, the percentage of lactate dehydrogenase (LDH) released into the medium was greater in CA1 than cortical cultures under the conditions of 24-h hypoxia and 24-h incubation (P < 0.05). We then added MK-801 (500 nM), cycloheximide (3 microM), L-NNA (100 microM) and anti-PAF IgG (50 micrograms/ml) prior to inducing the hypoxia and measured LDH in the medium after 24-h hypoxia and 48-h incubation. Under the hypoxic condition, MK-801, L-NNA, and anti-PAF IgG significantly protected the CA1 neurons from hypoxic injury compared with cortical neurons, while cycloheximide protected both cultures equally. These results suggest that CA1 neurons are more sensitive to hypoxia than cerebral cortical neurons, and glutamate, nitric oxide, and PAF may participate in the mechanism of selective neural death in neurons of the CA1 region due to hypoxia.
我们从出生后第1天（P1）大鼠的皮质和海马CA1区制备了富含神经元的培养物。利用这些培养物，我们研究了神经元对缺氧损伤的敏感性。还检测了MK-801、放线菌酮、NG-硝基-L-精氨酸（L-NNA）和抗血小板活化因子（抗PAF）IgG在缺氧条件下对神经元损伤的影响。尽管采用相同的培养程序，但CA1区培养物中的星形胶质细胞百分比高于皮质培养物。尽管有这一发现，但在24小时缺氧和24小时孵育条件下，CA1区培养物中释放到培养基中的乳酸脱氢酶（LDH）百分比高于皮质培养物（P<0.05）。然后，在诱导缺氧之前，我们添加了MK-801（500 nM）、放线菌酮（3 microM）、L-NNA（100 microM）和抗PAF IgG（50微克/毫升），并在24小时缺氧和48小时孵育后测量培养基中的LDH。在缺氧条件下，与皮质神经元相比，MK-801、L-NNA和抗PAF IgG能显著保护CA1区神经元免受缺氧损伤，而放线菌酮对两种培养物的保护作用相同。这些结果表明，CA1区神经元比大脑皮质神经元对缺氧更敏感，谷氨酸、一氧化氮和PAF可能参与了CA1区神经元因缺氧而发生选择性神经死亡的机制。
