目的 研究术后疲劳综合征（POFS）老年大鼠海马神经营养因子（NTF）水平动态变化及人参皂苷Rb₁的抗疲劳机制。方法 将96只老年雄性SD大鼠，随机分为假手术组、模型组和人参皂苷Rb₁干预组，每组再按时间点分为术后6 h及术后1、3、7 d组。术后对应时间点进行旷场试验，并通过Real-time PCR检测大鼠海马神经生长因子（NGF）、脑源性神经营养因子（BDNF）的mRNA表达；放射免疫法检测NGF和BDNF蛋白表达；电镜观察海马CA1区超微结构变化。结果 模型组与假手术组比较，旷场试验中大鼠穿越格子数减少（P＜0.01），休息时间延长（P＜0.01）；NGF和BDNF mRNA表达降低（P＜0.05、0.01），其相应的蛋白表达也降低（P＜0.05）。人参皂苷Rb₁组与模型组比较，旷场试验中大鼠穿越格子数增多（P＜0.05），NGF和 BDNF mRNA表达升高（P＜0.05、0.01），其相应的蛋白表达也升高（P＜0.01）。电镜结果显示，模型组与假手术组比较，大鼠海马神经元超微结构受损，人参皂苷Rb₁组得到相应改善。结论 POFS老年大鼠海马NTF表达降低，神经元存在一定程度损伤，人参皂苷Rb₁对POFS老年大鼠有一定改善作用。

Objective To investigate the dynamical variation of the hippocampal neurotrophic factors (NTF) in elderly rats with postoperative fatigue syndrome (POFS) and the antifatigue mechanism of ginsengside Rb₁. Methods Ninety-six elderly male SD rats were randomly divided into Sham, POFS model, and ginsengoside Rb₁ intervention groups, and each group was divided into subgroups by postoperative 6 h, 1, 3, and 7 d. The hippocampus was removed at each time point after open field test (OFT) to detect the mRNA expression levels of nerve growth factors (NGF) and brain-derived neurotrophic factors (BDNF) by Real-time PCR; The content of protein was detected by radioimmunoassay; The ultrastructural changes in hippocampus CA1 area were observed by electron microscopy. Results Compared with the Sham group, the number through lattice in OFT of rats in the POFS model group declined (P < 0.01), while resting time increased (P < 0.01); The expression level of NGF and BDNF mRNA in the POFS model group declined (P < 0.05, 0.01), the expression level of corresponding protein declined (P < 0.05). Compared with the POFS model group, the number through lattice in OFT of rats in the Rb₁ group increased (P < 0.05), the expression level of NGF and BDNF mRNA of rats in Rb₁ group increased (P < 0.05, 0.01), and the expression level of corresponding protein also increased ( P < 0.01). Electron microscopy results showed that compared with the Sham group, the ultrastructures of the hippocampal neurons of rats were significantly damaged in the POFS model group, which were relatively impromed in the Rb₁ group. Conclusion The expression level of NTF inelderly rats with POFS declines, the hippocampal neurons are damaged to a certain extent and the application of ginsenoside Rb₁ may have the improvement to POFS in elderly rats.