十溴联苯醚（PBDE-209）暴露对小鼠学习记忆能力的影响

Effect of exposure to higher decabrominated diphenyl ether （PBDE-209） on learning and memory functions of BALB/c mice

目的探讨十溴联苯醚（PBDE．209）暴露对小鼠学习记忆能力的影响，为防治PBDE．209危害提供依据。方法18只雌性BALB／c小鼠随机分成3组，每组6只，分别给予PBDE．209（1500mg·kg。·d。）＋精炼花生油（高剂量组）、PBDE-209（300mg·kg-1·d-1）＋精炼花生油（低剂量组）和0．1ml／10g体重花生油（对照组）灌胃。每日1次，连续染毒4周后做Morris水迷宫试验、穿梭箱试验（期间仍然给药），测定小鼠的学习记忆能力，待染毒5周后处死。测定体重、脏器重量、脑组织中乙酰胆碱酯酶活力和丁酰胆碱酯酶活力，观察肝脏细胞组织形态学变化。结果高剂量组心脏系数明显高于低剂量组，差异有统计学意义（P〈0．05）。Morris水迷宫试验结果显示，各组动物逃避潜伏期均有不同程度缩短，变化趋势差异有统计学意义（F=3．134，P〈0．05）；低剂量染毒组在第2象限游泳时间为（15．78±10．92）S，明显短于对照组[（28．80±8．67）S】，差异有统计学意义（P〈0．05）。穿梭箱试验显示，各组主动逃避次数差异无统计学意义（F=3．423，P=0．06）。与对照组比较，各染毒组脑组织乙酰胆碱酯酶活力和丁酰胆碱酯酶活力的差异无统计学意义（P〉0．05）。染毒组肝脏出现脂肪变性和肿胀，高剂量组尤为明显。结论4周龄BALB／c小鼠暴露于PBDE-209在一定程度上可影响小鼠空间学习记忆能力。

Objective To investigate the effects of exposure to decabrominated diphenyl ether （PBDE-209） on learning and memory of BALB/c mice. Methods Eighteen female BALB/e mice were ran- domizedly divided into 3 groups and gavaged with peanut oil in the control groups and 300,1500 mg·kg-1· d-1 PBDE-209 in peanut oil daily in two exposed groups respectively for 4 weeks. The learning and memory ability of mice were tested by the Morris water maze and the shuttling box respectively. The body weight and organs index were measured and the acetylcholinesterase and butyrylcholinesterase activity in brain were determined. The liver histopathological examination was performed. Results The heart index in high dose PBDE-209 group was higher than that of the low dose PBDE-209 group （P〈0.05）. The results of Morris water maze showed that escape latency period was significantly shorter than the control group （F=3.134 ,P〈0.05 ）. The swimming time in the second quadrant of low dose PBDE-209 group was （15.78± 10.92） s, significantly shorter compared with the swimming time in the second quadrant of the control group＇s [（28.80± 8.67）s]（P〈O.05）. There was no significant difference in the times of active avoidance in the shuttling between three groups （F=3.423, P= 0.06）. There were no significant differences in acetylcholinesterase and butyrylcholinesterase activity in brain of PBDE-209 groups compared with the control group（P〉0.05 ）. Histologically liver damages in structure such as adipose degeneration and swelling were observed in PBDE groups. Conclusion Exposure to PBDE-209 slightly impairs the space learning and memory ability of BALB/c mice, and it has some hepototoxicity.