溴氰菊酯亚慢性染毒对小鼠神经行为及海马NMDA受体表达的影响

Effect of sub-chronic exposure to deltamethrin on neural behavior and expression of NMDA receptor in hippocampus of mice

目的研究溴氰菊酯（DM）亚慢性染毒对小鼠神经行为和海马谷氨酸受体（NMDA）表达的影响。方法清洁级雌性昆明小鼠60只，分为4组，通过灌胃连续染毒60d，热板试验、转棒试验、抓力试验和后肢支撑力测试检测小鼠感觉、运动行为的改变；自主活动能力测试反应小鼠中枢神经系统的功能状态；避暗试验检测小鼠学习、记忆行为的改变；RQ—PCR技术检测海马NMDA受体mRNA的表达。结果DM亚慢性染毒后小鼠在感觉、运动功能方面未出现明显改变（P〉0．05）；自主活动能力测试染毒剂量组小鼠平均自主活动次数为（93±18）次、（107±13）次、（105±22）次，与溶剂对照组比较，中、高剂量组小鼠平均自主活动次数增加，差异有统计学意义（P〈0．05）。避暗试验染毒剂量组小鼠潜伏期分别为（175．4±38．4）s、（146．4±51．2）s、（132．3±45．0）s，失败次数分别为（0．7±0．3）次、（1．4±0．5）次、（1．8±0．9）次，与溶剂对照组比较，高剂量组小鼠潜伏期缩短，中、高剂量组失败次数增加，差异有统计学意义（P〈0．05）；与溶剂对照组比较，中、高剂量组小鼠海马NPd、NR2AmRNA相对表达水平均增高（P〈0．05），高剂量组NR2BmRNA的相对表达水平降低（P〈0．05）。结论DM亚慢性染毒可引起小鼠自主活动次数增加、学习和记忆功能损伤，并影响海马神经元NMDA受体mRNA的表达。

Objective To study the effect of sub-chronic exposure to deltamethrin（DM） on neural behavior and expression of NMDA receptor in hippocampus of mice. Methods 60 Female SPF Kunming mice were divided into 4 groups and given DM 60 days by gavage. Hot-plate, rotarod, grip strength, hing limb landing foot splay were used to examine the sensory and motor change of mice. Autonomic activity test was used for detecting the functional status of the central nervous system in mice. Passive avoidance test for detection of the behavior changes of learning and memory, and RQ-PCR was employed to measure the expression of NMDA receptor in hippocampus of mice. Results The behavior of sensory and motor of mice sub-chronic exposure to dehamethrin did not have changes significantly （P 〉 0.05 ）. In the test of autonomic activity test, the average of autonomic activity times were （93 ± 18） times, （107 ± 13） times, （105 ± 22） times. Compared with the control group,the average of autonomic activity times in middle-and high-dose groups were increased significantly（P〈 0.05 ）. The latent periods in poisoning groups were （ 175.4 ± 38.4 ） s, （ 146.4 ± 51.2 ） s, （ 132.3 ± 45.0 ） s, and the error times were （ 0.7 ± 0.3 ） times, （ 1.4 ± 0.5 ） times, （ 1.8 ± 0.9 ） times. Compared with the control group,latent periods of high-dose group were decreased and the error times of middle-and high-dose groups were increased significantly （P 〈 0.05 ）. Compared with the control group, the relative expression levels of NRI and NR2A mRNA in hippocampus of middle and high-dose groups were increased significantly （P 〈 0.05 ） , and the relative expression level of NR2B mRNA in highdose group was decreased significantly（P 〈 0.05 ）. Conclusion Sub-chronic exposure to DM could increase the excitability of mice, damage the function of learning and memory, and influence the expression of NMDA receptor in hippocampus of mice.