目的 研究西红花苷-1对急性低氧条件下大鼠学习记忆及海马区沉默信息调节因子1（SIRT1）表达的影响。方法 SD大鼠随即分为5组：对照组，低氧模型组，西红花苷-1低、中、高剂量（25、50、100 mg/kg）组。西红花苷-1各组每天im给药1次，给药3 d后低氧环境下刺激72 h，采用Morris水迷宫观察大鼠的学习记忆行为，免疫组化法与Western blotting法检测大鼠海马SIRT1蛋白表达。结果 与低氧模型组相比，西红花苷-1各剂量使Morris水迷宫实验中大鼠逃避潜伏期均明显缩短，且穿越平台次数增加（P＜0.05）。免疫组化和Western blotting法检测显示，西红花苷-1各组大鼠海马组织SIRT1蛋白表达均显著高于低氧模型组（P＜0.05），其中以中、高剂量组作用明显。结论 西红花苷-1预先给药，可增加急性低氧大鼠海马组织SIRT1蛋白表达，这可能是其改善低氧条件下大鼠学习记忆的机制之一。

Objective To investigate the effect of crocin-1 on behavior of learning and memory in rats under acute hypoxia and on the expression of silent information regulator l (SIRT1) in hippocampus of rats. Methods SD rats were randomly divided into five groups: control, hypoxia model, low- , mid-, and high-dose (25, 50, and 100 mg/kg) crocin-1 groups. The SD rats in crocin-1 groups were im administered once daily for 3 d and then were stimulated for 72 h under hypoxia. Morris water maze was used to investigate the learning and memory behaviors. Immunohistochemical staining and Western blotting were used to detect the SIRT1 expression. Results The escape latency in crocin-1 groups was shorter than that in hypoxia model group, while the frequency of bestriding platform was increased (P < 0.05). Immunohistochemical staining and Western blotting both showed that the expression level of SIRT1 was higher in crocin-1 groups than that in hypoxia model group (P < 0.05), and the expression levels in mid- and high-dose groups were obviously higher. Conclusion Crocin-1 could increase the expression of SIRT1 in hippocampus of rats, which maybe one of the important mechanisms for crocin-1 improving learning and memory function of SD rats under acute hypoxia.

国家自然科学基金资助项目（81260685）；教育部“春晖计划”合作项目（Z2010063）