摘要目的 评价七氟醚与异丙酚不同配比静吸复合麻醉对老龄大鼠术后认知功能的影响.方法 健康老龄雄性Wistar大鼠60只,18～ 20月龄,体重600～ 650 g,采用随机数字表法,将其分为6组(n=10):对照组(C组)、七氟醚麻醉组(S组)、异丙酚麻醉组(P组)、七氟醚与异丙酚不同配比复合麻醉组(SP1组、SP2组和SP3组).C组静脉输注10 ml生理盐水;S组吸入3.1％七氟醚,P组静脉输注异丙酚40 mg·kg-1·h-1;SP1组吸入2.4％七氟醚复合静脉输注异丙酚10 mg·kg-1·h-1;SP2组吸入1.8％七氟醚复合静脉输注异丙酚20 mg·kg-1·h-1;SP3组吸入1.2％七氟醚复合静脉输注异丙酚30 mg·kg-1·h-1,麻醉时间均为2h.除C组外,其它5组翻正反射消失后行胫骨骨折切开复位内固定术.于麻醉后1d时进行Y迷宫实验,记录新异臂停留时间和各个臂穿梭次数总和,进行恐惧条件化实验,确定僵直时间比率,以反映认知功能;然后处死大鼠,取海马组织,采用West-ern blot法测定occludin、基质金属蛋白酶-2和基质金属蛋白酶-9的表达.结果 与C组比较,其它5组新异臂停留时间缩短,各臂穿梭次数总和及僵直时间比率降低,海马occludin表达下调,海马基质金属蛋白酶-2和基质金属蛋白酶-9表达上调,SP2组上述指标变化最不明显(P＜0.05或0.01).结论 七氟醚与异丙酚不同配比静吸复合麻醉可降低老龄大鼠术后认知功能,吸入1.8％七氟醚复合静脉输注异丙酚20 mg·kg-1·h-1麻醉对术后认知功能的影响较小.

abstractsObjective To evaluate the effects of different ratios of medicine dosage for sevoflurane and propofol on postoperative cognitive function in aged rats.Methods Sixty healthy male Wistar rats,aged 18-20 months,weighing 600-650 g,were divided into 6 groups (n =10 each) using a random number table:control group (group C),sevoflurane anesthesia group (group S),propofol anesthesia group (group P) and different ratios of mmedicine dosage for sevoflurane and propofol groups (group SP1,group SP2 and group SP3).Normal saline 10 ml was infused intravenously in group C.Group S inhaled 3.1％ sevoflurane.Propofol was infused intravenously at a rate of 40 mg · kg-1 · h-1 in group P.In group SP1,2.4％ sevoflurane was inhaled,and propofol was intravenously infused at a rate of 10 mg · kg-1 · h-1.In group SP2,1.8％ sevoflurane was inhaled,and propofol was intravenously infused at a rate of 20 mng · kg-1 · h-1.In group SP3,1.2％ sevoflurane was inhaled,and propofol was intravenously infused at a rate of 30 mg · kg-1 · h-1.Duration of anesthesia was 2 h in all the groups.After loss of righting reflex,open reduction and internal fixation was performed after tibial fracture was induced in the other five groups except group C.At 1 day after anesthesia,Y-maze test was performed,and the time spent on the novel arm and total number of entries into each arm were recorded,and fear conditioning test was carried out for determination of the rate of freezing time to reflect the cognitive function.The rats were sacrificed after behavioral testing,and the hippocampus was removed for determination of occludin,matrix metalloproteinase-2 (MMP-2) and MMP-9 expression by Western blot.Results Compared with group C,the time spent on the novel arm was significantly shortened,the total number of entries into each arm and rate of freezing time were decreased,the expression of occludin was down-regulated,the expression of MMP-2 and MMP-9 was up-regulated in the other five groups,and the most unmarked change in the indices mentioned above was found in group SP2 (P＜ 0.05 or 0.01).Conclusion Different ratios of medicine dosage for sevoflurane and propofol can induce postoperative cognitive decline,and inhaling 1.8％ sevoflurane and infusing propofol 20 mg · kg-1 · h-1 produce little influence on postoperative cognitive function in aged rats.