远志皂苷元对老年大鼠术后认知障碍的影响

Effect of Senegenin on Splenectomy- induced Postoperative Cognitive Dysfunction in Elderly Rats

目的观察远志皂苷元对全脾切除术后发生术后认知障碍(postoperative cognitive dysfunction,POCD)的老年大鼠的影响并探讨作用机制。方法 140只SD雄性大鼠被随机分配到7个组,每组20只。对照组C组(group C)无需经历手术。其余120只大鼠均需手术,并分为单纯手术组(group S1、S3、S5)及术后远志皂苷元治疗组(group T1、T3、T5)。术前所有大鼠均进行为期5天的Morris水迷宫(MWM)训练。训练后,单纯手术组(group S)进行全脾切除术,术后不予以远志皂苷元治疗,而治疗组(group T)术后均予以远志皂苷元治疗,在术后第1、3、5天均进行MWM。术后第1、3、5天测定大鼠海马组织中炎性细胞因子和信号通道相关的mRNA表达水平。结果在全脾切除术后第1天,S组、T组在水中滞留的时间、游到平台的距离、炎性细胞因子和信号通道相关的mRNA表达水平都明显高于C组(P<0.05)。但是T组升高的程度却远小于S组(P<0.01)。T组在术后第3天、S组在术后第5天上述3个特性与group C对比,差异无统计学意义(P>0.05)。结论老年大鼠全脾切除术可导致短暂性认知缺陷,远志皂苷元治疗可显著改善上述短暂性认知缺陷,其机制可能与其明显抑制一些炎性细胞因子和信号通道相关的mRNA的表达有关。

Objective To investigate the effects of senegenin on the cognitive functions of elderly rats with splenectomy - induced postoperative cognitive dysfunction（POCD）. Methods Totally 140 SD rats were randomly assigned to seven groups,each group contai- ning 20rats. In the control group（ group C） ,the rats were not subjected to surgery. The remaining 120 rats were divided into surgery（ group S1 ,S3, S5） and senegenin treatment group （ group T1 ,T3, T5 ）. All rats were trained in the Morris water maze（MWM） for five days. Fol- lowing training,the rats in group S underwent spleneetomy without senegenin treatment,while the rats in group T underwent splenectomy with senegenin treatment. All tats were re -assessed using the MWM on days 1,3 ,and 5 following surgery. On days 1,3and 5 postopera- tively^tested the mRNA expression of several key pro- inflammatory cytokines, and the mRNA expression of Toll- like receptor 4 （TLR4）. Results On day 1 postoperatively, despite the swimming speed remaining unchanged, the latency and swimming distance and the mRNA expression levels of a number of key proinflammatory cytokine and the expression of Toll - like receptor 4 in group S and group T were significantly increased when compared with those in group C （P 〈 0.05 ）. However, in group T the degree of increase was not as great as that in group S1 （P 〈0.01 ）. On day 3 in group T and on day 5 in group S following the splenectomy, these characteristics had re- turned to normal （compared with group C,P 〉 0.05）. Conclusion Splenectomy induced a transient cognitive deficiency in the elderly rats. Senegenin exhibited neuroprotective effects against splenectomy - induced transient cognitive impairment in elderly rats. The mecha- nism may be that senegenin significantly inhibited the mRNA expression of several key pro - inflammatory cytokines, and the Toll - like re- ceptor 4.