生物节律紊乱对大鼠异丙酚镇静效应的影响

Effects of biological rhythm disturbance on sedation induced by propofol in rats

目的 评价生物节律紊乱对大鼠异丙酚镇静效应的影响.方法 成年雄性SD大鼠32只,体重180～220 g,采用随机数字表法,将其分为4组（n=8）：近日节律夜间给药组（CN组）、近日节律日间给药组（CD组）、生物节律紊乱夜间给药组（BN组）和生物节律紊乱日间给药组（BD组）.CN组和CD组于12h光照（7：00-19：00）/12 h黑暗（19：00-7：00）交替的实验箱饲养2周;BN组和BD组于24 h光照的实验箱中饲养2周.CN组和BN组分别于14：00时腹腔注射异丙酚75mg/kg;CD组和BD组分别于22：00时腹腔注射异丙酚75 mg/kg.记录翻正反射消失的持续时间,并于翻正反射恢复后20 min时,测定认知功能,分别于学习训练后6、12、24和48 h时,记录被动回避潜伏期.结果 与CN组比较,CD组翻正反射消失持续时间缩短,学习训练后12 h时被动回避潜伏期延长,BN组翻正反射消失持续时间、学习训练后12和24 h时被动回避潜伏期均缩短（P＜0.05或0.01）;与CD组比较,BD组翻正反射消失持续时间差异无统计学意义（P＞0.05）,学习训练后24 h时被动回避潜伏期缩短（P＜0.05）;BN组与BD组间翻正反射消失持续时间和被动回避潜伏期比较差异无统计学意义（P＞0.05）.结论 生物节律紊乱可抵消近日节律对异丙酚镇静效应的影响.

Objective To evaluate the effects of biological rhythm disturbance on sedation induced by propofol in rats.Methods Thirty-two adult male Sprague-Dawley rats,weighing 180-220 g,were randomly divided into 4 groups （n =8 each） using a random number table：circadian rhythm ＋ administration during night-time group （group CN）,circadian rhythm ＋ administration during day-time group （group CD）,biological rhythm＋administration during night-time group （group BN）,and biological rhythm＋administration during day-time group （group BD）.In CN and CD groups,the rats were fed for 2 weeks in the experimental boxes in a 12 （7：00-19：00）：12 h （19：00-7：00） light：dark cycle.While the rats were fed for 2 weeks in the experimental boxes in a 24 h light cycle.Propofol 75 mg/kg was intraperitoneally injected at 14：00 in CN and BN groups,or at 22：00 in CD and BD groups.The duration of loss of righting reflex was recorded.At 20 min after recovery of righting reflex,the cognitive function was assessed.The latency of passive avoidance was measured at 6,12,24 and 48 h after training.Results Compared with group CN,the duration of loss of righting reflex was significantly shortened,and the latency of passive avoidance was prolonged at 12 and 24 h after training in group CD,and the duration of loss of righting reflex and latency of passive avoidance at 12 and 24 h after training were shortened in group BN.Compared with group CD,no significant change was found in the duration of loss of righting reflex,and the latency of passive avoidance was significantly shortened at 24 h after training in group BD.There was no significant change between BN group and BD group in the duration of loss of righting reflex and latency of passive avoidance.Conclusion Biological rhythm disturbance can counteract circadian rhythmproduced effects on sedation induced by propofol in rats.