α-细辛醚对Fmr1基因敲除小鼠跳台行为和海马P-Akt表达的影响

Effects of α-asarone on step-down test and expressions of P-Akt in hippocampus of Fmr1 knockout mouse

目的通过观察α-细辛醚对Fmr1基因敲除小鼠(KO鼠)跳台行为和海马磷酸化蛋白激酶B(P-Akt)表达的影响,初步探讨α-细辛醚对KO鼠学习记忆缺陷的治疗作用及其可能的机制。方法采用4周龄纯合子(-/-)FVB Fmr1基因敲除型及4周龄纯合子(+/+)FVB野生型(WT)近交系小鼠小鼠共计231只。KO及WT小鼠各分7组,分别为:空白对照组,阴性对照组(生理盐水组),α-细辛醚治疗组3 mg/kg组,6 mg/kg组,9 mg/kg组,12 mg/kg组,24 mg/kg组,KO小鼠每组16只;WT小鼠每组17只。4周龄小鼠予连续腹腔注射生理盐水及α-细辛醚6 d,第7天腹腔注射30 min后行跳台实验(第1天),测定小鼠避暗及跳台潜伏期和错误次数,第8天腹腔注射30 min后行跳台实验(第2天),测定小鼠避暗及跳台潜伏期和错误次数,第9天腹腔注射30 min后取脑海马,并通过Western blot观察小鼠海马内P-Akt及Akt表达。结果跳台实验结果:KO小鼠阴性对照组,3 mg/kg,6 mg/kg,9 mg/kg及12 mg/kg用药组的跳台潜伏期较空白对照组有明显增高(P<0.05),而在24 mg/kg组,虽然潜伏期较空白组有增加,但是无统计学意义差异(P>0.05)。KO小鼠各组的跳台实验错误次数之间无统计学差异(P>0.05)。WT小鼠腹腔注射生理盐水及不同剂量α-细辛醚后,各组间的跳台实验的潜伏期及错误次数均无统计学差异(P>0.05)。KO小鼠海马中的P-Akt均较WT小鼠明显减少。而Akt的表达在KO及WT小鼠中均无统计学意义的变化(P>0.05)。用药后KO小鼠各用药组之间P-Akt表达变化无统计学差异(P>0.05)。结论部分α-细辛醚剂量可改善KO小鼠的跳台行为,KO小鼠的Akt通路可能受损,这可能是导致KO小鼠学习记忆受损的可能原因之一。

Objective To discuss the therapeutic effects of the memory defect and possible mechanism of a - asarone, by observing its in-fluence on jumping avoidance test on KO mice and expression of P - Akt. Metheds 4 - week - old homozygous （ - / - ） FVB FMR1 gene knock addition to the type （KO） and 4 - week - old homozygous （/） FVB wild - type （WT） inbred mice were divided into seven groups blank control group, negative control group （saline group） , a - asarone treatment group 3 mg/kg group, 6 mg/kg group, 9 mg/kg group, 12 mg/kg group, 24 mg/kg group, with 16 KO mice in each group, a total of 112 ; and 17 WT mice in each group, a total of 119. The total number of KO and WT mice was 231. 4 - week - old mice accepted intraperitoneal injection of saline and a - asarone for 6 days, and in the 7th day （first day） after intraperitoneal injection for 30 minutes, step down test was performed and passive avoidance and jumping latency and the number of errors were detected ; In the 8th day （second day） after intraperitoneal injection for 30 minutes, step down test was performed and passive avoidance and jumping latency and the number of errors were detected; the 9th day after intraperitoneal injection for 30 minutes, the expression of the P - Akt, and Akt in the hippocampus of the brain were observed by Western blot method. Results Step down test results ： Jumping latency of the KO mice negative control group, 3 mg/kg, 6 mg/kg, 9 mg/kg and 12 mg/kg treatment group was significantly higher than the control group （ P 〈 0 .0 5 ） , but there was statistically significant difference in 24 mg/kg group （ P 〉 0. 0 5 ） . The number of errors of KO mice in each group has no significant difference （ P 〉0.05）. There was no significant difference when compared different indicators of WT mice （ P 〉0. 0 5 ） . Hippocampus P - Akt expression of KO mice was significantly reduced than those in WT mice. Expression of Akt in KO and WT mice has no statistically significantly difference （ P 〉 0. 05）. P - Akt expression of KO mice in each treatment group has no significant difference （ P 〉 0. 05 ） . Conclusion Part dose of the α - asarone can improve the KO mice jumping behavior. Damage of Akt pathway in KO mice may be one of the possible reasons for the KO mice impaired learning and memory.