液压冲击对体外神经细胞钙超载的影响及牛磺酸的作用

目的 探讨液压冲击对体外神经细胞钙超载的影响及牛磺酸的作用.方法 将体外培养的神经细胞随机分为①正常对照组:将未经任何处置的神经细胞分为24 h组和48 h组;②创伤组:液压冲击致神经细胞创伤24 h和48 h组;(3)牛磺酸组:分别于神经细胞创伤后0 h和1 h给予牛磺酸(终浓度为0.50 mmol/L)治疗.观察24 h和48 h,分别为0 h 24 h、0 h 48 h、1 h 24 h、1 h 48 h组.用激光扫描共聚焦显微镜(Iaser Scanning Confocal Microscope,LSCM)观察各组细胞形态,同时以Fluo-3/AM为钙离子荧光指示剂负载各组细胞,测定24 h和48 h后细胞内游离钙离子浓度([Ca2+]i)的变化.结果 ①组织形态学变化:与正常对照组比较,伤后24 h和48 h创伤组神经细胞胞体肿胀、突起回缩;牛磺酸治疗组神经细胞胞体无明显肿胀,突起回缩明显改善.②细胞内[Ca2+]i改变:创伤后即刻细胞内[Ca2+]i水平即开始升高,24 h达峰值水平,48 h仍维持于较高水平,显著高于正常组(P＜0.01);牛磺酸治疗0 h或1 h,24 h和48 h均能明显降低细胞内[Ca2+]i,创伤后1 h给药的[Ca2+]i显著低于0 h给药(P＜0.01),且随着时间的推移,对神经细胞的保护作用逐渐增强.结论 牛磺酸对液压冲击伤后大鼠神经细胞内Ca2+超载有较好的保护作用,创伤后1 h给药并维持48 h,对神经细胞保护作用最佳.

Effects of taurine on intracellular calcium overloadin neurons following fluid percussion injury

Objective To study the effects of taurine in different time on calcium overload in neurons of SD rats following fluid percussion injury (FPI).Methods The cultured rat neuronal cells were randomly divided into model group,taurine treatment group and normal control group.①Normal control group(NC):without any treatment for the rat neuronal cells;②FPI group:tested at 24 h and 48 h after injury using fluid percussion injury (FPI)③Taurine treatment group:the neuronal cells was cultured in vitro,the taurine intervention for the treatment was used immediately (0h) and 1h after injury respectively,the final concentration was 0.50 mmol*L-1.(0 h 24 h,0 h 48 h,1 h 24 h,1 h 48 h traurine group respectively).With the confocal laser scanning microscope,the[Ca2+]i in neuronal cell in 24 h and 48 h were measured using Fluo-3/AM as a calcium indicator.Results The neurons loaded by Fluo-3/AM in NC were round or clostridium with longer processes and intracellular[Ca2+]i was at a low level,its fluorescence distribution and intensity are weaker at 24 h and 48 h.In model group,the neurons at 24 h and 48 h after injury were swelling,with the processes retracted and the intracellular [Ca2+]i fluorescence distribution and intensity stronger than that of NC.The [Ca2+]i reached a peak at 24 h after injury and remain at higher levels to 48 h.There was no obvious neuron swelling in taurine treatment groups with the cell size closed to those in NC.The process of neurons was more complete and fluorescence distribution was uniform and the [Ca2+]i was lower significantly than that in the model group (P＜0.01).Compared with 0 h 24 h and 0 h 48 h taurine groups,the [Ca2+]i in 1 h 24 h and 1 h 48 h taurine group were significantly reduced(P＜0.01).The neuronal processes retraction and the [Ca2+]i in 48 h taurine groups were much more improved than those in 24 h taurine groups.Conclusion Taurine is effective in counteracting the calcium overload in neurons injured caused by hydraulic impact.There is a time window that is 1 h after injury and the duration of treatment should be kept for 48 h.