铅硒联合作用对大鼠海马突触结构参数的影响

Effect of lead and selenium on synaptic structural parameters in the hippocampus of Wistar rats

目的观察铅、硒对大鼠海马突触结构参数的影响,探讨铅致学习记忆损害机制及硒的拮抗作用。方法 Wistar大鼠随机分为对照组、单独染铅组、单独加硒组和铅硒同时组,至观察终点测定血铅和血硒值,利用透射电镜测定突触结构参数。结果单独染铅组较对照组,血铅值显著增高,突触间隙宽度明显增大,突触后致密物厚度、活性带长度及界面曲率明显减小(P<0.05);铅硒同时组与单独染铅组相比,血铅值降低,突触间隙宽度显著减小,突触后致密物厚度及活性带长度明显增大(P<0.05)。结论铅暴露可改变大鼠海马突触结构参数,从而对学习记忆造成影响;硒对铅致大鼠海马突触结构改变具有保护作用。

Objective To study the effect of lead（Pb） and（or） selenium（Se） on synaptic structural parameters in the hippocampus of Wistar rats,and discuss the mechanism of lead-induced damage to learning and memory,as well as the antagonism of selenium.Methods SPF Wistar rats,after weaning for 3 weeks,were divided into four groups： Control group,Pb group（respectively Pb exposed）,Se group（respectively Se added） and Pb ＋ Se group（Pb and Se exposed simultaneously）.After intervention for 3weeks in rats,blood levels of lead and selenium were measured by inductively coupled plasma-massspectrometry（ICP-MS） and the synaptic structural parameters in the hippocampus of rats in each group rats was measured by transmission electron microscope.Results Rats in Pb group had significantly higher blood lead level,obvious increase in synaptic cleft,while width of synaptic active zone,thinkness of postsynaptic density,and synaptic curvature were significantly reduced compared with control group（P0.05）; rats in Pb ＋ Se group had significantly narrower synaptic cleft,bigger width of synaptic active zone and bigger thinkness of postsynaptic density compared with Pb group（P0.05）.Conclusion Lead exposure can change synaptic structural parameters in the hippocampus resulting in learning and memory deficits in rats and organic selenium had protective effects on Pb-induced synaptic structural change.