脑创伤后神经元细胞内游离钙的变化及其影响因素(英文)

Changes of intracellular free Ca^(2+) in the neurons following brain trauma and the contributing factors

目的:研究液压冲击伤时体外培养的单个大鼠神经细胞内游离钙(犤Ca2+犦i)的变化,探讨尼莫地平D-2氨基戊酸(D-2-amino-5-phosphono-valericacid,D-AP-5)和亚低温对创伤后细胞内犤Ca2+犦i的影响及其机制。方法:以Fluo-3/AM为细胞内钙离子的荧光指示剂,用激光共聚焦显微镜测定液压冲击伤时体外培养的单个大鼠神经细胞内游离钙(犤Ca2+犦i)的变化。结果:液压冲击伤后脑皮质细胞内游离Ca2+迅速升高,24h达高峰,随后逐渐下降,48h仍维持较高水平犤(411.29±52.46),(396.53±51.32)nmol/L犦,尼莫地平,D-AP-5于各时相关均降低细胞内犤Ca2+犦i,其中Nimodipine10h内应用最佳犤6h:(98.65±15.65)nmol/L犦,D-AP-5于1～10h应用较好而亚低温30min内显著降低细胞内犤Ca2+犦i(t=13.74,P<0.001),最佳时机在伤后15min内,伤后1h以上无效。结论:创伤后神经元细胞内钙超载,尼莫地平、D-AP-5和亚低温均降低细胞内犤Ca2+犦i,但各自最佳时间窗不同,揭示对创伤后神经细胞Ca2+超载应注意综合治疗,并选定各自作用最佳时间窗。

AIM:To observe the changes of free calciu m in rat brain neurons cultured in vitro following blast injury induced by fluid percussion and to explore t he protective effect of mild hypotherm ia,nimodipine(Nim)and D-2-amino-5-phosphonovaleric aci d(D-AP-5)onCa 2+ i after injury.METHODS:Changes ofCa 2+ i in the rat brain neurons following fl uid percussion injury was measured by me ans of a confocal laser scanning mi-croscope using Fluo-3/AM as a calciu m fluorescent indicator.RESULTS:Ca 2+ i in the injured neurons increased acu tely,reaching the peak level(411.29±52.46nmol /L)at 24h after injury,and de-creased gradually afterwards,but s till maintained higher levels396.53±51.32)nmol /Lat 48h after the injury.Nim and D-AP-5decreasedCa 2+ i in the injured neurons at each time point following the in-jury.Application of Nim was recomme nded as early as possible following the injury,and relative poor effect may be expected within 10h after inju ryCa 2+ at(98.65±15.65)nmol /L 6h after the injury.Optimal occasion for application of D-AP-5was between 1and 10h after the in-jury.Hypothermia decreasedCa 2+ i markedly within 30min post injury(t=13.74,P<0.001)but seemed useless till 1h following the injury,and its optimal application was with in 15min after the injury.