【作者】 李丹；

【导师】 欧阳文；

【作者基本信息】 中南大学 ， 麻醉学， 2008， 硕士

【摘要】 目的检测不同浓度异氟醚吸入全身麻醉对老龄大鼠空间学习记忆能力的影响,通过应用Morris水迷宫训练行行为学观察并使用光镜观察麻醉后老龄大鼠海马CA3区突触素的改变,希望为探讨老龄大鼠异氟醚麻醉后认知功能变化的机理提供理论依据,以期更好地阐明麻醉后认知功能障碍的发生机制。方法69只24月龄SD大鼠,随机分为A组（n=21）、B组发n=24)和C组（n=24）。A组为吸氧对照组,老龄SD大鼠只吸入含40%氧气的空氧混合气体3小时。B组以异氟醚3%浓度诱导,待翻正反射消失后再以1.2%浓度维持3小时,吸入麻醉过程中其吸入氧浓度为40%,C组同样以异氟醚3%浓度诱导,待翻正反射消失后再以1.8%浓度维持3小时,吸入麻醉过程中其吸入氧浓度为40%,待麻醉结束后任其自然苏醒。B、C组随机抽取3只大鼠在麻醉过程中行股动脉穿刺监测老龄大鼠的生命体征。麻醉结束后24小时,应用Morris水迷宫对A、B、C三组随机抽取的12只大鼠开始连续7天的行为学观察,记录逃避潜伏期和探索时间。麻醉结束后24小时(分别为A_24h组、B_24h组和C_24h组)、72小时(分别为A_24h组、B_24h组和C_24h组)和7天(分别为A_7d组、B_7d组和C_7d组),从三组中各取3只老龄大鼠取大脑组织固定、包埋、切片、行突触素的免疫组化染色,再使用Motic BA400/450显微镜观察并采用Moticimage advanced 3.2图像分析系统分析海马CA3区突触素的变化。结果①.麻醉后24小时A、B、C三组的逃避潜伏期差异无显著性（P＞0.05）。麻醉后48小时B组逃避潜伏期为44.16±17.91s,C组逃避潜伏期为47.41±20.94s,均长于A组23.61±13.91s（P＜0.01）。麻醉后72小时B组逃避潜伏期为26.80±11.51s,C组逃避潜伏期为27.08±11.64s,均长于A组14.87±8.37s（P＜0.05）。麻醉后第四天至麻醉后第六天三组间的逃避潜伏期差异无显著性,麻醉后第七天A、B、C三组的探索时间差异无显著性。②.光镜下麻醉结束后24小时B、C组大鼠海马CA3区的突触素平均灰度值为152.89±8.59;160.67±4.59,高于A组141.26±7.48s（P＜0.05）,麻醉结束后72小时B、C组大鼠海马CA3区的突触素平均灰度值为161.46±5.94;170.56±2.60,高于A组144.0±4.90s（P＜0.01）,麻醉结束后第七天B、C组大鼠海马CA3区的突触素平均灰度值为171.40±4.19;180.08±3.03,高于A组138.60±6.28s（P＜0.01）。结论1.2%、1.8%异氟醚吸入麻醉3小时的过程中,老龄SD大鼠的生命体征平稳。麻醉后,老龄SD大鼠空间学习记忆能力下降,但这种影响在麻醉结束后第四天趋于消失。老龄SD大鼠海马组织CA3区突触素表达下调一直持续到麻醉后第七天,而且1.8%异氟醚麻醉下调作用更明显。更多还原

【Abstract】 Objective To investigate the change of hippocampal synaptophysin and spatial learning memory functions after isoflurane general anesthesia in aged rats.We want to find some morphology evidences in the research of aged rats’ cognitive changes,so as to elucidate sufficiently the mechanism of cognitive dysfunction after isoflurane anesthesia.Methods Sixty-nine 24-month-old SD rats were randomly divided into three groups.The rats in group A（n=21）only inhaled mixed gas containing 40%oxygen for three hours.The rats in group B（n=24）were induced by inhalation of 3%isoflurane,after body-righting reflex disappeared,we used 1.2%isoflurane to maintain anesthesia for 3 hours. The fraction of inspired oxygen was 40%in the course of anesthesia.The rats in group C（n=24）were also induced by inhalation of 3%isoflurane, after body-righting reflex disappeared,we used 1.8%isoflurane to maintain anesthesia for 3 hours.The fraction of inspired oxygen was 40% in the course of anesthesia.Let the rats naturally wake up after anesthesia. Three rats were randomly taken from each group of group B and group C for monitoring vital sign by femoral arteriopuncture in the course of anesthesia.Twelve rats were randomly taken from each group to carry out the ethology observation for 7days with Morris water maze 24 hours after oxygen inhalation or isoflurane general anesthesia,escape latency and probe time were recorded.Three rats were randomly selected from each group at 24h(A_24h、B_24hand C_24h)、72h(A_72h、B_72hand C_72h)and 7day(A_7d、B_7dand C_7d)after oxygen inhalation or isoflurane general anesthesia.The brains of the aged rats mentioned above were collected and then were fixed,embedded,sectioned and stained.The change of synaptophysin in hippocampus CA3 area was observed by means of Motic BA400/450 microscope and Motic imaged advanced 3.2 image analysis system,Results①.There is no significant difference between A_24h、B_24h and C_24hin escape latency（p＞0.05）.The excape latency is 44.16±17.91s in B_48hand 47.41±20.94s in C_48h,Which is longer than 23.61±13.91s in A_48h（p＜0.01）.The escape latency is 26.80±11.51s in B_72hand 27.08±11.64s in C_72h,Which is also longer than 14.87±8.37s in A_72h （p＜0.05）.There is no significant difference in escape latency from the fourth day after oxygen inhalation or isoflurane general anesthesia to the sixth day.The probe time is no significant difference in the seventh day after oxygen inhalation or isoflurane general anesthesia.②.The mean gray scale value of the synaptophysin of the hippocampus CA3 area is 152.89±8.59s in B_24hand 160.67±4.59s in C_24h,Which is higher than 141.26±7.48s in A_24h（p＜0.05）,the mean gray scale value of the synaptophysin of the hippocampus CA3 area is 161.46±5.94s in B_72hand 170.56±2.60s in C_72h,Which is higher than 144.0±4.90s in A_72h （p＜0.01）,and the mean gray scale value of the synaptophysin of the hippocampus CA3 area is 171.40±4.19s in B_7dand 180.08±3.03s in C_7d,Which is higher than 138.60±6.28s in A_7d（p＜0.01）.Conclusion The vital sign of aged rats is stable during the course of 1.2%and 1.8%isoflurane general anesthesia.The spatial learning memory of aged rats decrease after anesthesia,but it recovery at the fourth day after anesthesia.The expression of synaptophysin in hippocampus CA3 area is continuous down-regulated till seventh day after anesthesia,and the expression is more obvious in 1.8%isoflurane general anesthesia group.更多还原