异氟烷对创伤性脑损伤大鼠的神经保护作用及作用机制研究

Neuroprotective Effect of Isoflurane in Rats with Traumatic Brain Injury and Its Mechanism

目的探讨异氟烷对创伤性脑损伤大鼠的神经保护作用及作用机制。方法选择成年健康雄性SD大鼠80只,采用随机数字表法分为假手术组、脑损伤组、异氟烷预处理组和异氟烷后处理组,每组20只。采用改良Feeney自由落体法制作大鼠创伤性脑损伤模型,假手术组大鼠仅做开窗手术处理,异氟烷预处理组大鼠在造模前给予异氟烷持续麻醉,脑损伤组和异氟烷后处理组大鼠造模成功后立即进行复苏,且异氟烷后处理组大鼠于复苏后给予异氟烷持续麻醉。采用神经功能缺损评分表(NSS)评定各组大鼠创伤性脑损伤后12 h、24 h神经功能缺损情况,免疫印迹法检测各组大鼠创伤性脑损伤后24 h损伤灶周围脑组织磷酸化Akt(P-Akt)、磷酸化糖原合酶激酶-3β(PGSK3β)、Bcl-2、cleaved-caspase-3蛋白表达量,TUNEL法检测各组大鼠创伤性脑损伤后24 h损伤灶周围脑组织凋亡神经元数量。结果脑损伤组大鼠创伤性脑损伤后12 h、24 h NSS评分高于假手术组、异氟烷预处理组及异氟烷后处理组,异氟烷预处理组和异氟烷后处理组大鼠创伤性脑损伤后12 h、24 h NSS评分高于假手术组(P<0.05)。脑损伤组、异氟烷预处理组及异氟烷后处理组大鼠创伤性脑损伤后24 h损伤灶周围脑组织P-Akt蛋白和P-GSK3β蛋白表达量高于假手术组,异氟烷预处理组和异氟烷后处理组大鼠创伤性脑损伤后24 h损伤灶周围脑组织P-Akt A蛋白和P-GSK3β蛋白表达量高于脑损伤组(P<0.05)。脑损伤组大鼠创伤性脑损伤后24 h损伤灶周围脑组织Bcl-2蛋白表达量低于假手术组、异氟烷预处理组及异氟烷后处理组,cleaved-caspase-3蛋白表达量及凋亡神经元数量高于假手术组、异氟烷预处理组及异氟烷后处理组,异氟烷预处理组和异氟烷后处理组大鼠创伤性脑损伤后24 h损伤灶周围脑组织cleaved-caspase-3蛋白表达量、凋亡神经元数量高于假手术组(P<0.05)。结论异氟烷对创伤性脑损伤大鼠具有神经保护作用,其可能通过激活Akt/GSK3β信号通路而发挥神经保护作用。

Objective To investigate the neuroprotective effect of isoflurane in rats with traumatic brain injury and its mechanism. Methods A total of 80 healthy male adult S-D rats were selected and divided into groups A,B,C,D,each of 20 rats. Modified Feeney freely falling body method was used to prepare rat model of traumatic brain injury,rats of A group were given open-window operation,rats of B group were given continue anesthesia of isoflurane before prepartion,rats of C group and D group were given CPR after preparation,and rats of D group were given extra continue anesthesia of isoflurane after CPR. NSS was used to evaluate the neurologic deficits after 12 hours and 24 hours of traumatic brain injury,immunoblotting was used to detect the protein expression of P-Akt,P-GSK3β,Bcl-2 and cleaved-caspase-3 in brain tissues around nidus after 24 hours of traumatic brain injury,and TUNEL was used to detect the apoptotic nerve cell amount in brain tissues around nidus after 24 hours of traumatic brain injury. Results NSS score after 12 hours and 24 hours of traumatic brain injury of C group was statistically significantly higher than that of A group,B group and D group,respectively,and that of B group and D group was statistically significantly higher than that of A group （ P〈0. 05 ）. Protein expression of P-Akt and P-GSK3β inbrain tissues around nidus after 24 hours of traumatic brain injury of B group,C group and D group were statistically significantly higher than those of A group,those of B group and D group were statistically significantly higher than those of C group（ P〈0. 05）. Protein expression of Bcl -2 in brain tissues around nidus after 24 hours of traumatic brain injury of C group was statistically significantly lower than that of A group,B group and D group,respectively,while protein expression of cleaved-caspase-3 and apoptotic nerve cell amount of C group were statistically significantly higher than those of A group,B group and D group,protein expression of cleaved-caspase -3 and apoptotic nerve cell amount of B group and D group were statistically significantly higher than those of A group （ P〈0. 05 ）. Conclusion Isoflurane has certain neuroprotective effect in rats with traumatic brain injury,it may play a role of neuroprotection by activating the Akt/GSK3β signal pathway.