局灶低温治疗大鼠脑外伤对脑组织SOD、MDA的影响

Role of local hypothermia on traumatic brain edema and oxidative stress in brain tissue in rats

目的观察局灶低温治疗对大鼠脑创伤后氧自由基的影响。方法SD大鼠84只,随机分成3组,每组28只:A组,假手术对照组:B组,脑外伤模型对照组:C组,25℃水局灶低温治疗组。除A组外各组动物均按Feeney方法造成重度脑创伤(traumaticbraininjury,TBI),B组伤后不予治疗,C组伤后30min开始给以局灶低温治疗,20～30min局灶脑温降至31℃并维持3h。各组又根据伤后观察时间长短分1、3、5和7d等四个亚组,每亚组7只。所有动物分别于伤后l、3、5、7d处死,取伤区脑组织测水含量及总超氧化物歧化酶(T-SOD)、丙二醛(MDA)含量。结果B组与A组比,脑组织水含量和MDA含量升高、T-SOD含量下降(1、3、5和7d组均P<0.05)。C组与B组相比,C组水含量和MDA含量降低、T—SOD含量升高(1、3、5、7d组均P<0.05)。结论对大鼠脑创伤后脑水肿,25℃水局灶低温治疗有效,减少丙二醛生成、抑制氧自由基反应可能是其作用机制之一。

[Objective]To investigate the effect of local hypothermia (LH) on traumatic brain edema and oxidative stress in brain tissue. 84 adult SD rats were randomly divided into three groups: group A, sham injury group; group B, TBI controlled group; group C, treated by LH with water of 25℃. All animals except group A were subjected to TBI with Feeney′s method. LH began for animals in group C 30 minutes after TBI. Within 20~30 minutes regional brain temperature reached the target temperature of 31℃ and maintained for three hours. Each group were divided in four sub-groups by investigating duration after TBI: one day (1 d), three day (3 d), five days (5 d) or seven day (7 d) sub-group. At the end of investigating duration animal was sacrificed and water content (WC), concentration of total superoxide dismutase (T-SOD) and malondialdehyde(MDA) in brain tissue were measured. Compared with group A, WC and MDA of group B increased but T-SOD decreased significantly (1 d, 3 d, 5 d, and 7 d, P <0.05). Compared with group B, WC and MDA of group C decreased but T-SOD increased significantly (1 d, 3 d, 5 d, and 7 d, P <0.05). [Conclusion] Local hypothermia with water of 25℃ had effect on traumatic brain edema. The mechanism of Local hypothermia may associate with inhibiting oxidative reaction.