山茱萸环烯醚萜苷对穹隆海马伞切断大鼠学习记忆能力和突触生长素的影响

Effect of cornel iridoid glycoside on learning-memory ability and synaptophysin in fimbria-fornix transacted rats

目的:探讨山茱萸环烯醚萜苷(cornel iridoid glycoside,CIG)对脑损伤大鼠模型学习记忆能力的影响及其作用机制。方法:采用穹隆海马伞切断(Fimbria-fornixtransaction,FFT)制备机械性脑损伤大鼠模型。造模后灌胃给予CIG(20,60和180 mg.kg-1)21 d,应用避暗试验和Morris水迷宫试验测定大鼠学习记忆能力的变化。然后立即取脑,采用免疫组织化学染色法和Western blot法测定脑海马区突触生长素(syn-aptophysin,SYP)表达的变化。结果:在避暗试验中,FFT模型大鼠潜伏期较假手术对照组明显缩短(P<0.01),CIG(60和180 mg.kg-1)组与模型组相比潜伏期显著延长(P<0.05)。在Morris水迷宫试验中,模型大鼠逃避潜伏期与假手术对照组相比明显延长(P<0.01),CIG(20和60 mg.kg-1)灌胃给药可显著缩短模型大鼠的逃避潜伏期(P<0.05,P<0.01)。免疫组织化学和Western blot检测结果显示,模型组大鼠海马区SYP表达比假手术对照组明显减少(P<0.01);CIG(20,60和180 mg.kg-1)可显著增高模型大鼠脑海马区SYP的表达水平(P<0.05,P<0.01)。结论:CIG灌胃给药能够提高FFT模型大鼠的学习记忆能力,推测其机制之一可能与CIG增强海马区SYP的表达、从而促进突触重建有关。

Objective： To investigate the effect of cornel iridoid glycoside（CIG） on learning-memory ability and its mechanisms in rats with brain injury. Methods： Mechanical brain injury was induced by fimbria-fornix transaction（FFT） in rats. After the operation, rats were administered by intragastric CIG （20, 60 and 180 mg· kg^-1） for 21 days. The learning and memory abilities were determined by the step-through test and Morris water maze test. Then the brain was immediately removed, and the expression of hippocampal synaptophysin（SYP） was detected by immunohistoehemistry and Western blotting. Results： In the step-through test, the FFT rats showed shorter latency as compared with the sham-operated rats（ P 〈 0.0l ）. Intragastrie CIG （ 60 and 180 mg· kg^-1 ） significantly prolonged the latency of FFT rats（P 〈0.05） rats was significantly longer than that in sham-operated In the Morris water maze test, the escape latency in FFT rats（P 〈0.01）, and CIG（20 and 60 mg· kg^-1） obviously rats（P 〈0.05, P 〈 0.01 ）. Conclusion： Intragastric administration of CIG markedly improved learning-memory ability in FFT rats, and one of the mechanisms may be related to elevating hippocampal SYP expression and thus promoting synapses restitution.