高原低氧对胎鼠海马神经元N-甲基-D-天冬氨酸受体发育的影响(英文)

Changes of N methyl D aspartate receptors in the hippocampal neurons of newborn rats subjected to fetal high altitude hypoxia☆

目的:观察高原低氧环境对胎鼠海马神经元N-甲基-D-天(门)冬氨酸受体(N-methyl-D-aspartatereceptor,NMDAR)数目和通道特性的影响,为防治高原低氧引起的脑损伤提供依据。方法:将孕10dSD大鼠置于低压氧舱内,采用原位杂交和膜片钳观察其所生子鼠海马NMDA受体的数量和功能。结果:胎鼠高原低氧后,NMDA受体数量减少,通道开放概率由0.150降为0.012,通道开放时间常数б1由0.040±0.010降为0.020±0.007(t=33.21,P<0.05),б2由0.75±0.23降为0.49±0.23(t=25.31,P<0.05),通道关闭时间常数б1由0.14±0.07升高为14.25±3.5(t=12.74,P<0.01),б2由2.67±1.12升高为4832±1809(t=8.44,P<0.01)。结论:高原低氧影响到胎鼠NMDA受体的发育,提示高原低氧环境下大鼠的学习记忆可能受到影响。

AIM:To observe the effects of simulated high altitude hypoxia on N methyl D aspartate receptors(NMDAR) in newborn rats,so as to provide theoretical basis for preventing and treating high altitude hypoxia induced cerebral injury. METHODS:Ten SD rats in pregnancy for 10 d were subjected to treatment in hypoxic chamber.In situ hybridization technique and patch clamp were employed to identify the number and function properties of NMDAR in the newborn rats. RESULTS:Simulated high altitude hypoxia resulted in decreased NMDAR expression and reduced channel opening probability(from 0.150 to 0.012),and the open time constant б1 of the channel was lowered from 0.040±0.010 to 0.020±0.007(t=33.21,P< 0.05),and б2 from 0.75±0.23 to 0.49±0.23(t=25.31,P< 0.05).In contrast,the channel close time constant б1 increased from 0.14±0.07 to 14.25±3.5(t=12.74,P< 0.01),and б2 from 2.67±1.12 to 48.32±18.09(t=8.44,P< 0.01). CONCLUSION:High altitude hypoxia can affect NMDAR development in newborn rats,suggesting that learning and memory capacity of rats might be impaired in high altitude hypoxia environment.