摘要
目的 评价局部浅低温对大鼠全脑缺血再灌注时10号染色体上缺失的磷酸酶与张力蛋白同源物基因（PTEN）蛋白表达的影响.方法 健康成年雄性Wistar大鼠108只,体重230 ～ 280 g,采用随机数字表法,将其分为3组（n=36）：假手术组（S组）、脑缺血再灌注组（I/R组）和浅低温脑缺血再灌注组（HI/R组）.采用Pulsinelli四血管阻断法烧灼椎动脉,夹闭双侧颈总动脉15 min后恢复灌注,建立全脑缺血再灌注损伤模型,HI/R组采用鼻咽腔降温法降低海马温度至32.5～33.5℃时夹闭双侧颈总动脉,并维持低温1h后自然复温,期间维持直肠温度36.5 ～ 37.5℃.于颈总动脉夹闭前即刻（T0）、再灌注4、8、12、24和72 h（T1-5）时分别随机取6只大鼠,处死取海马组织,采用免疫组化法检测海马CA1区磷酸化PTEN（p-PTEN）蛋白、Bcl-2蛋白和Bax蛋白表达,计算Bcl-2蛋白和Bax蛋白表达的比值,采用ELISA法检测S100B蛋白含量,采用硫代巴比妥酸显色法检测MDA含量和黄嘌呤氧化酶法测定SOD活性.结果 与S组比较,I/R组再灌注后海马p-PTEN蛋白、Bcl-2蛋白表达水平、Bcl-2/Bax蛋白比值及SOD活性降低,Bax蛋白表达、MDA和S100B蛋白含量升高（P＜0.05）,HI/R组Bcl-2/Bax蛋白比值降低（P＜0.05）,而p-PTEN蛋白、Bcl-2蛋白表达水平、SOD活性、MDA和S100B蛋白含量差异无统计学意义（P＞0.05）;与I/R组比较,HI/R组再灌注后海马p-PTEN蛋白、Bcl-2蛋白表达水平、Bcl-2/Bax蛋白比值及SOD活性升高,Bax蛋白表达水平、MDA和S100B蛋白含量降低（P＜0.05）.结论 局部浅低温减轻脑损伤的作用机制与抑制大鼠全脑缺血再灌注时PTEN蛋白活化有关.
Objective To evaluate the effect of local mild hypothermia on the expression of phosphatase and tensin homolog deleted on chromo-some ten （PTEN） protein during global cerebral ischemia-reperfusion （I/R） in rats.Methods One hundred and eight healthy adult male Wistar rats,weighing 230-280 g,were randomly divided into 3 groups （n =36 each） using a random number table：sham operation group （group S）,cerebral I/R group （group I/R） and mild hypothermia cerebral I/R group （group HI/R）.Global cerebral I/R was induced by 4-vessel occlusion method described by Pulsinelli.Bilateral vertebral arteries were permanently occluded by cauterization,and bilateral carotid arteries were occluded for 15 min.Nasopharyngeal cooling was applied and the nasopharyngeal temperature was reduced to 32.5-33.5 ℃ and maintained at this level for 1 h.When the nasopharyngeal temperature was reduced to 32.5-33.5 ℃,the bilateral carotid arteries were clamped in group HI/ R.Six rats were chosen to be anesthetized and sacrificed immediately before ischemia and at 4,8,12,24 and 72 h of reperfusion.Hippocampal specimens were obtained to detect the expression of phosphorylated PTEN （pPTEN）,Bcl-2 and Bax protein （by immunohistochemistry） in hippocampal CA1 region,contents of S100B protein （by ELISA） and MDA （by thiobarbituric acid method）,and activity of SOD （by xanthine oxidase method）.Results Compared with group S,the expression of p-PTEN and Bcl-2 protein,ratio of Bcl-2/Bax protein and activity of SOD were significantly decreased,and the expression of Bax protein and contents of MDA and S100B protein were increased after reperfusion in group I/R （P 〈 0.05）,and the ratio of Bcl-2/Bax protein was decreased,and there was no significant difference in the expression of p-PTEN,Bcl-2 and Bax protein,activity of SOD and contents of MDA and S100B protein after reperfusion in group HI/R （P 〉 0.05）.Compared with group I/R,the expression of p-PTEN and Bcl-2 protein,Bcl-2/Bax ratio and activity of SOD were significantly increased and the expression of Bax protein and content of MDA and S100B protein were decreased after reperfusion in group HI/R （P 〈 0.05）.Conclusion The mechanism by which local mild hypothermia reduces cerebral damage is related to inhibition of activation of PTEN protein in the brain tissues during global cerebral I/R in rats.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2013年第12期1474-1477,共4页
Chinese Journal of Anesthesiology
基金
河北省自然科学基金
