治疗性高碳酸血症联合亚低温对大鼠脑缺血再灌注损伤的影响  

Effects of therapeutic hypercapnia combined with mild hypothermia on cerebral ischemia-reperfusion injury in rats

作　　者：周强[1] 金迪[1] 王洪亮[1] ZHOU Qiang;JIN Di;WANG Hong-liang(Department of Anesthesiology,The Second Affiliated Hospital of Harbin Medical University,Harbin 150081,China)

机构地区：[1]哈尔滨医科大学附属第二医院麻醉科

出　　处：《哈尔滨医科大学学报》2019年第4期367-371,共5页Journal of Harbin Medical University

基　　金：黑龙江省教育厅科学技术研究项目(12511268)

摘　　要：目的探讨治疗性高碳酸血症联合亚低温对大鼠脑缺血再灌注损伤的影响及其机制。方法健康雄性SD大鼠80只,随机分成4组(n=20):假手术组(SH组);脑缺血再灌注组(IR组);PaCO280~100 mmHg组(P组);PaCO280~100 mmHg联合亚低温组(PM组)。采用双侧颈总动脉夹闭合并低血压法建立前脑缺血再灌注模型。P、PM组于再灌注同时吸入CO22 h,使PaCO2维持在80~100 mmHg;PM组于再灌注吸入CO2同时给予亚低温。再灌注24 h后进行神经功能缺陷评分,测定海马超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、caspase-3活性以及Caspase-3蛋白表达。结果与SH组比较,其余3组再灌注24 h后神经缺陷评分升高,海马SOD活性降低,MDA含量升高,caspase-3活性增加,Caspase-3酶原蛋白表达下调,裂解片断表达上调(P<0.01);与IR组比较,P组和PM组神经功能缺陷评分降低,海马SOD活性增加,MDA含量降低,caspase-3活性降低,Caspase-3酶原蛋白上调,裂解片断表达下调;与P组比较,PM组神经功能缺陷评分降低,海马SOD活性增加,MDA含量降低,caspase-3活性降低,Caspase-3酶原蛋白表达上调,裂解片断表达下调(P<0.05)。结论治疗性高碳酸血症联合亚低温可减轻大鼠脑缺血再灌注损伤,且脑保护作用强于单独应用治疗性高碳酸血症,其机制与减轻氧化应激、降低caspase-3活性有关。Objective To investigate the effects of therapeutic hypercapnia combined with mild hypothermia(MH) on cerebral ischemia-reperfusion(IR) injury in rats and its mechanism. Methods Eighty male Sprague Dawley rats weighting 260~300 g were randomly divided into 4 groups(n=20): SH group(sham operation), IR group, P group(PaCO2 80~100 mmHg+IR), and PM group(PaCO2 80~100 mmHg+MH). Rats in IR group were induced by occlusion of bilateral common carotid arteries combined with controlled hypotension for 10 min. In P and PM groups, CO2 was inhaled for 2 hours to keep PaCO2 within the range of 80~100 mmHg after reperfusion, and the PM group was given mild hypothermia therapy.The neurologic deficit evaluation was performed at the end of 24 h reperfusion. Animals were killed after neurologic deficit evaluation. Brains were immediately removed to observe SOD activity, MDA content, Caspase-3 expression and activity by colorimetric method, and Western blot assays. Results In IR group, the score of neurologic deficit evaluation, MDA content and Caspase-3 activity increased, SOD activity decreased, the expression of pro-Caspase-3 decreased and the cleavage of pro-Caspase-3 increased after 24 hours reperfusion compared with SH group(P<0.01). In P group and PM group, the scores of neurologic deficit evaluation, MDA content and caspase-3 activity decreased, SOD activity increased, the expression of pro-Caspase-3 decreased and the cleavage of pro-Caspase-3 increased, the cleavage of pro-Caspase-3 was restrained compare with IR group. Meanwhile, PM group showed more protection of IR injury compared to P group(P<0.05). Conclusion Therapeutic hypercapnia combined with mild hypothermia can lighten the injury of IR and enhance the cerebral protection in rats. And the brain protection is stronger than the therapeutic hypercapnia alone. The mechanism probably is that oxidative stress restrains the degradation of pro-Caspase-3 and decreases the activity of Caspase-3.

关 键 词：治疗性高碳酸血症 亚低温 再灌注损伤 脑 

分 类 号：R743[医药卫生—神经病学与精神病学]