锂对染铅大鼠海马胆囊收缩素和神经元型一氧化氮合酶神经元的保护作用

目的 探讨锂对染铅大鼠海马胆囊收缩素（CCK）和神经元型一氧化氮合酶（nNOS）神经元的保护作用及其与动物学习记忆功能变化的关系.方法 通过测量体重,利用反映学习记忆功能的Y迷宫法和ABC免疫组化法,研究饮用含0.2 g/L醋酸铅（PbAc）水和含不同剂量（3、30、300、3 000mg/kg）氯化锂（LiCl）饲料喂养的大鼠体格发育情况、学习记忆能力以及海马不同亚区CCK和nNOS阳性神经元数目的变化.结果铅染毒组大鼠体重增加少于对照组大鼠,差异有统计学意义（P＜0.05）,Y-迷宫学会次数多于对照组大鼠,差异有统计学意义（P＜0.05）;其海马各区CCK和nNOS阳性神经元数明显减少,差异有统计学意义（P＜0.05）.铅＋LiCl（3、30、300mg/kg）组体重增加多于对照组大鼠,差异有统计学意义（P＜0.05）;Y-迷宫学会次数少于对照组大鼠,差异有统计学意义（P＜0.05）,海马各区CCK阳性神经元数明显增加,差异有统计学意义（P＜0.05）.铅＋3 000mg/kg LiCl组大鼠Y-迷宫学会次数多于对照组大鼠,差异有统计学意义（P＜0.05）;海马各区CCK阳性神经元数明显少于对照组,差异有统计学意义（P＜0.01）;与铅染毒组比较,差异无统计学意义（P＞0.05）.结论 铅可损伤大鼠学习记忆能力,影响大脑海马CCK和nNOS阳性神经元的数目.较低剂量的锂对铅引起的学习记忆损伤和海马CCK阳性神经元的变化有一定保护作用.

Protection of lithium on hippocampal cholecystokinin and nitric oxide synthase neuron in lead exposed rats

Objective To investigate the effect of lithium on hippocampal cholecystokinin(CCK) and neuronal nitric oxide synthase(nNOS) positive neurons and its relationship to the learning and memory ability of lead exposed rats. Methods Wistar rats were randomly divided into the control group,the lead group,four lead+LiCl (3,30,300,3 000 mg/kg) groups.Four lead+LiCl groups were fed with food containing 3,30,300,3 000 mg/kg LiCl respectively.The lead+LiCl groups and the lead group were administered with distilled water containing 0.2% PbAc.The body weight was measured and the difference of body development was observed.Y-maze test was used for studying the effects of lead on the learning and the memory ability in rats.ABC immunohistochemistry was used for investigating the changes of CCK positive neurons in hippocampus of lead-exposed rats. Results Compared with the control group and the lead+LiCl groups,the learning and memory ability of lead exposed rats was significantly higher (P<0.05).The number of CCK positive neurons in hippocampus lead exposed rats fed with lithium(3,30,300 mg/kg) was significantly higher than that in the lead exposed rats(P<0.05). Conclusion The lead may damage the learning-memory ability of the rats.It might be related to the changes of CCK positive neurons in hippocampus in lead exposed rats.The lithium of the low dose might play an important role in preventing lead-induced damages.