不同温度对脑外伤后伤灶区c-fos mRNA,NGF表达的影响

Effects of different temperature on cerebral c-fos mRNA,NGF expression following traumatic brain injury

目的通过对大鼠重型脑挫裂伤后体温的干预,观察不同温度对脑外伤后伤灶区c-fos mRNA,NGF表达的影响,了解其表达是否与伤后不同温度对脑损伤的保护或加重损伤有关。方法健康成年SD大鼠336只,随机分为4组,除假手术组外各组动物均按自由落体法造成重度脑挫裂伤;每组又按处死时间分为7个亚组,分别检测c-fos mRNA与NGF的表达。结果①伤后4、8、12与24 h,亚低温组c-fos mRNA表达明显高于TBI组,TBI组表达明显高于高温组。②伤后4和8 h,亚低温组NGF表达与TBI组无明显差异;其他各时间点,亚低温组NGF表达明显高于TBI组;在伤后第4、8小时及第7天,高温组NGF表达与TBI组无明显差异;在其他各时间点,高温组NGF表达明显低于TBI组。结论脑外伤后全身亚低温可促进c-fosmRNA,NGF表达上调,脑外伤后高温可明显降低c-fos mRNA,NGF表达。

【Objective】To observe the effects of different temperature on cerebral c-fos mRNA,NGF expression following traumatic brain injury and also to understand its protection or aggravation to brain injury.【Methods】Adult SD rats 336 were randomly divided into four groups.Three groups were subjected to traumatic brain injury by the Feeney＇s method except for Sham Operation Group.Every group was then separated to 7 subgroups according to different decapitated time.c-fos mRNA and NGF expression was then determined respectively.【Results】① c-fos mRNA expression in hypothermia group was significantly higher than TBI group which was significantly higher than hyperthermia group at 4h,8h,12h and 24h after traumatic brain injury;② NGF expression in hypothermia group was significantly higher than TBI group at different time point after traumatic brain injury except for 4h and 8h which were no significant difference.NGF expression in hyperthermia group was significantly lower than TBI group at different time point after traumatic brain injury except for 4 h,8 h and 7 d which were no significant difference.【Conclusion】Systemic hypothermia after traumatic brain injury could up-regulate the expression of c-fos mRNA and NGF,on the contrary,hyperthermia after traumatic brain injury could down-regulate the expression of c-fos mRNA and NGF.