orexin在大鼠异氟醚麻醉后睡眠紊乱中的作用

Role of orexin in sleep disorder after isoflurane anesthesia in rats

目的 评价orexin在大鼠异氟醚麻醉后睡眠紊乱中的作用.方法 雄性SD大鼠64只,体重280 ～ 320 g,10～ 12周龄,采用随机数字表法,将其分为2组（n=32）：对照组（C组）和异氟醚组（Ⅰ组）.Ⅰ组于8：00-13：30吸入1.2％异氟醚麻醉,恢复0.5 h,C组不接受麻醉,其余同Ⅰ组.记录麻醉诱导和觉醒时间.随机取8只大鼠,于14：00-次日8：00记录活动情况（自发活动时间和活跃度）;于麻醉开始前、麻醉开始后4h和麻醉结束后4、10 h时随机取6只大鼠,取脑组织,计数下丘脑活化的orexin神经元（orexin/c-fos共标阳性神经元）,计算活化比例（orexin/c-fos共标阳性神经元与orexin阳性神经元的比值）;取动脉血样,测定血浆orexin-A浓度.结果 Ⅰ组麻醉诱导时间（2.14±0.17） min,觉醒时间（8.7±0.5） min,脑电监测未出现典型爆发性抑制波.2组orexin阳性神经元计数差异无统计学意义（P＞ 0.05）.与C组比较,Ⅰ组夜间自发活动时间延长,活跃度升高,且麻醉开始后4h活化的orexin神经元计数及活化比例和血浆orexin-A浓度降低（P＜0.01）.与麻醉开始前比较,Ⅰ组血浆orexin-A浓度于麻醉开始后4h降低,而在麻醉结束后10 h升高（P＜0.05）;与麻醉开始后4h比较,Ⅰ组麻醉开始前和麻醉结束后10 h活化的orexin神经元计数及活化比例升高,麻醉结束后4、10h血浆orexin-A浓度升高（P＜0.05或0.01）.结论 大鼠日间异氟醚麻醉后睡眠紊乱的发生与orexin在其中的调节作用有关.

Objective To evaluate the role of orexin in the sleep disorder after isoflurane anesthesia in rats.Methods Sixty-four male Sprague-Dawley rats,aged 10-12 weeks,weighing 280-320 g,were randomly divided into 2 groups （n =32 each） using a random number table：control group （C） and isoflurane group （Ⅰ）.Group Ⅰ inhaled 1.2% isoflurane from 8：00 to 13：30 to induce anesthesia,followed by 0.5 h of recovery.Group C received no anesthesia and the other procedures were similar to those previously described in group Ⅰ.The induction time and awakening time were recorded.Eight rats were randomly chosen to record the movement condition （locomotor time and activity） from 14：00 to 8：00 the next morning.Before beginning of anesthesia,at 4 h after beginning of anesthesia,and at 4 and 10 h after the end of anesthesia,6 rats were randomly chosen in each group to count the orexin/c-fos double-labeled neurons in hypothalamus.The ratio of activated orexin neurons （orexin/c-fos double-labeled neurons to orexin positive neurons） was calculated and plasma orexin-A concentration was detected.Results The induction time was （2.14 ± 0.17） min,awakening time was （8.7 ± 0.5） min,and EEG showed that there was no typical burst and suppression patterns in group Ⅰ.There was no significant difference in the number of orexin positive neurons between the two groups （P 〉 0.05）.Compared with group C,the time for locomotor activity was significantly prolonged,and the activity was increased during the night （P 〈 0.01）,the number of activated neurons,ratio of activated orexin neurons and plasma orexin-A concentration were decreased at 4 h after beginning of anesthesia in group Ⅰ （P 〈 0.01）.The plasma orexin-A concentration was lower at 4 h after beginning of anesthesia,while higher at 10 h after the end of anesthesia than before beginning of anesthesia in group Ⅰ （P 〈 0.05）.The number of activated neurons was significantly larger and ratio of activated orexin neurons was higher before beginning of anesthesia and at 10 h after the end of anesthesia and the plasma orexin-A concentration was higher at 4 and 10 h after the end of anesthesia than at 4 h after beginning of anesthesia in group Ⅰ （P 〈 0.05 or 0.01）.Conclusion The development of sleep disorder after isoflurane anesthesia during the day time in rats is related to the regulatory role of orexin in it.