中文摘要：

目的 评价异氟醚后处理对缺血缺氧性脑损伤新生大鼠脑组织线粒体通透性转换孔（mPTP）的影响.方法 新生SD大鼠120只,7日龄,体重12～ 16 g,采用随机数字表法分为4组（n=30）：假手术组（S组）、异氟醚组（I组）、缺血缺氧性脑损伤组（HIBI组）及缺血缺氧性脑损伤＋异氟醚后处理组（HI组）.HIBI组和HI组永久性结扎左颈总动脉后,置于低氧环境（8％O2-92％N2混合气体）2h,以制备缺血缺氧性脑损伤模型.HI组于缺氧缺血性脑损伤模型制备后即刻吸入1.5％异氟醚30 min.I组仅吸入1.5％异氟醚30 min,不制备模型.于缺氧缺血性脑损伤模型制备后24h时,随机取10只大鼠,处死后取脑组织,测定线粒体mPTP开放程度;于缺氧缺血性脑损伤模型制备后7d,记录大鼠生存情况,处死后取脑,计算丘脑腹后内侧核及海马CA3区左右侧正常神经元密度比值;分离左侧和右侧大脑半球并称重,计算左右侧大脑半球质量百分比.结果 4组大鼠生存率比较差异无统计学意义（P＞0.05）;与S组比较,HIBI组和HI组丘脑腹后内侧核及海马CA3区左右侧正常神经元密度比值、左侧大脑半球质量及左右侧大脑半球质量百分比降低,脑组织mPTP开放程度升高（P＜0.05）,I组上述各项指标差异无统计学意义（P＞0.05）;与HIBI组比较,HI组丘脑腹后内侧核及海马CA3区左右侧正常神经元密度比值、左侧大脑半球质量及左右侧大脑半球质量百分比升高,脑组织mPTP开放程度降低（P＜0.05）.结论 异氟醚后处理减轻新生大鼠脑缺血缺氧性脑损伤的机制可能与抑制脑组织mPTP开放有关.

英文摘要：

Objective To evaluate the effects of isoflurane postconditioning on mitochondrial permeability transition pore （mPTP） in brain tissues of neonatal rats with hypoxic-ischemic brain injury.Methods One hundred and twenty 7-day-old Sprague-Dawley rats,weighing 12-16 g,were randomly divided into 4 groups （n =30 each） using a random number table：sham operation group （group S）,isoflurane group （group I）,hypoxicischemic brain injury group （group HIBI）,and hypoxic-ischemic brain injury ＋ isoflurane postconditioning group （group HI）.To establish hypoxic-ischemic brain injury model in the neonatal rats,the left common carotid artery ligation was carried out,and then the rats were exposed to 8% O2 ＋ 92% N2 at 37 ℃ for 2 h in HIBI and HI groups.The rats inhaled 1.5 % isoflurane for 30 min after the model was established in group HI.The rats only inhaled 1.5% isoflurane for 30 min in group I.At 24 h after the model was established,10 rats taken out randomly in each group were sacrificed and brains were removed to detect mPTP opening.At 7 days after the model was established,the survival rate was recorded in the rest rats.The rats were then sacrificed and brains were removed and the right and left cerebral hemispheres were weighed separately,and the ratio between left/right cerebral hemispheres was calculated.The density of normal neurons in ventral posterior inferior thalamic nucleus and hippocampal CA3 region in the left and right cerebral hemispheres were measured and the ratios of the density of normal neurons in the left to right cerebral hemisphere were calculated.Results There was no significant difference in the survival rate between the four groups （P 〉 0.05）.Compared with group S,the ratios of the density of normal neurons in the left to right cerebral hemisphere,weight of left cerebral hemisphere,and ratio between left/right cerebral hemispheres were significantly decreased,and mPTP opening was increased in group HIBI （P 〈 0.05）,and no significant changes were found in the