手术创伤对老年大鼠认知功能的影响

目的探讨手术创伤对老年大鼠认知功能的影响及其机制。方法SD雄性大鼠70只，随机分为手术组和对照组，各35例。手术组水合氯醛麻醉后行脾切除手术，对照组仅行水合氯醛麻醉。两组分别于手术前1d（T0）和手术后1（T1）、3（T3）、5（T5）和7d（T7），用Morris水迷宫方法测试大鼠的认知功能，荧光定量聚合酶链式反应（RTFQ-PCR）定量检测海马区腺苷酸活化激酶（AMPK）mRNA的表达，免疫组化计数法检测海马星形胶质细胞胶质纤维酸性蛋白（GFAP）的表达。结果与TO比较，手术组T1、T3逃避潜伏期、总路程明显延长（F=4．65、29．46，q=3．21～4．52，P＜0．05）；T1、T3和T5的AMPKmRNA表达明显增高（F=12．84，P＜0．05），T1、T3星形胶质细胞GFAP表达明显增高（F=82．08，q=3．47～4．89，P＜0．05）。与对照组比较，手术组T1、T3的逃避潜伏期、总路程明显延长（t=2.97～5．80，P＜0．05）；T1、T3、T5的AMPK mRNA表达明显增高（t=2．52～9．78，P＜O．05），T1、T3星形胶质细胞GFAP的表达明显增高（t=2．20、4．74，P＜0．05）。对照组麻醉后各时间点各指标比较差异无显著性（P＞0．05）。结论大鼠脾切除术引起了海马区AMPK mRNA表达增高，海马区星形胶质细胞被激活，并且出现了短暂的认知功能损伤。

IMPACT OF SURGICAL TRAUMA ON COGNITIVE FUNCTION IN AGED RATS

Objective To explore the effect of surgical trauma on cognitive function in aged rats and its mechanism. Methods Seventy SD male rats were evenly randomized to two groups as operation group and control group. The rats in the operation group underwent splenectomy under chloral hydrate anesthesia, and those in the control group received only chloral hydrate anesthesia. The cognitive function was tested in the two groups-1 day before operation （To）, and 1 （T1）,3 （T3）,5 （T5） and 7 （T7） days after operation-by Morris water maze method, the expression of AMPK mRNA in hippocampus was detected by RTFQ PCR, and GFAP expression in the astrocyte in hippocampus field immunohistochemisty. Results Compared with T0, the latency period at T1 and T3 was escaped and the total distance was significantly extended （F=4.65,29.46;q = 3.21-4.52;P〈0.05）. the AMPK expression at T1, T3 and T5 significantly increased （F = 12.84, P〈0.05）; the expression of GFAP in astrocyte was significantly increased at T1 and T3 （F=82.08,q=3.47-4.89,P〈O.05）. Compared with the control group, the latency period at T1 and T3 in the operation group was escaped and the total distance significantly extended （t = 2.97-5.80, P〈0.05） ; the expression of AMPK mRNA at T1, T3 and T5 significantly elevated （t=2.52-9.78,P〈0.05）; the expression of GFAP at T1 and T3 increased （t=2.20-4.74,P〈0.05）. In the control group, the differences of the parameters between each time point were not significant （P〉0.05）. Conclusion Transitory cognitive function damage appears in rats due to elevation of AMPK mRNA and ac tivation of astrocytes in hippoeampus after splenectomy.