纳洛酮对铝致学习记忆减退大鼠学习记忆的影响

目的　研究纳洛酮对铝致学习记忆减退大鼠的学习记忆能力的影响。方法　采用慢性氯化铝灌胃方法 ,制备学习记忆减退大鼠模型后随机分为模型组和纳洛酮治疗组 ,另设正常对照组。结果　 (1)模型组和治疗组大鼠海马铝含量均比正常组显著升高 (P <0 .0 5 ) ,而两者之间无明显差异 (P >0 .0 5 ) ;(2 )Morris水迷宫定位航行实验中 ,模型组大鼠全部 6次训练和治疗组大鼠在第 5、第 6次训练的逃避潜伏期比正常组明显延长 (P <0 .0 5 ) ,其中治疗组大鼠的潜伏期比模型组大鼠显著缩短 (P <0 .0 5 )。双因素重复测量方差分析显示纳洛酮对三组大鼠的隐匿平台逃避潜伏期有显著的影响 (P <0 .0 0 1) ;(3)探索实验中模型组大鼠穿越次数比正常组大鼠明显减少 (P <0 .0 1) ,治疗组大鼠与正常大鼠相比无明显差异 (P >0 .0 5 ) ;(4)三组动物的可见平台逃避潜伏期无明显组间差别 (P >0 .0 5 )。结论　纳洛酮可明显改善铝致学习记忆减退大鼠的学习记忆能力 ,而且该作用并非通过降低大鼠海马的铝含量。

Effect of naloxone on learning and memory in aluminum-induced learning and memory impairment rats

Objective To study the effect of naloxone on spatial learning and memory in aluminum-induced learning and memory impairment rats. Methods Aluminum-induced learning and memory impairment model was established by gavage of Aluminum chloride (60mg/100g bodyweight) for 3 months, the successful models were randomly divided into two groups viz. naloxone treated rats and nontreated model rats, the former received naloxone injection (i.p.) for 7days, while the latter and the normal control group received the same volume saline injection in the same time. Then all the rats trained in Morris water maze. Aluminum (Al) and zinc (Zn) contents in hippocampus were assayed with atomic absorption spectrophotometry. Results (1) The hippocampus Al contents of model group rats and naloxone treated group rats were elevated as compared with that of normal group animals respectively ( P <0.05). (2) The latencies in the hidden platform trials were significantly longer in all trails of the model rats and in the 5 and 6 trails of naloxone rats compared to the normal controls ( P <0.05). Escape latencies were significantly reduced in naloxone group rats as compared with that of model rats ( P <0.05). (3) In probe trails, the number of entries of model group rats was significantly less than that of normal group ( P <0.01), meanwhile there was no significant difference in naloxone group and normal group ( P >0.05). (4) In the visible platform trails, there was no significant difference in escape latency among the three groups ( P >0.05). Conclusions Naloxone can facilitate the spatial learning and memory in aluminum-induced learning and memory impairment rats, without decreasing the hippocamous Al contents.