妊哺期沥青烟染毒对仔鼠海马脏器系数及学习记忆的影响

Influence of bitumen fume exposure on hippocampus(learning and memory ability) of their offspring in mice during gestation and lactation

目的了解研究母鼠妊娠期和哺乳期沥青烟染毒对仔鼠学习记忆和海马组织脏器系数的影响。方法昆明种成年母鼠40只,随机分成高、中、低剂量组和对照组,每组10只。母鼠自孕第1 d置于1 m3静式染毒柜内,开始沥青烟染毒2 h/d,至仔鼠出生后21 d断乳。染毒剂量为165(LD0)、82(1/2 LD0)、41(1/4 LD0)mg/m3。分别于出生后第7、14、21 d测定仔鼠体重和海马组织重量并计算其脏器系数;21 d用Y型迷宫测定仔鼠学习记忆能力T1、T2、T3(以仔鼠连续10次测试中成功9次即为获得记忆,以总测试次数减10得到的差值记为T1,3 d后再用同样方法复测,结果记为T2,以公式(T1-T2)/T1×100%计算记忆保持率记为T3。测定或检查时每窝随机取1只仔鼠,每组取10只。结果高剂量染毒组仔鼠21 d体重显著低于对照组(P<0.05);出生不同时间点高剂量染毒组仔鼠海马组织重量及其脏器系数显著高于对照组(P<0.01);Y型迷宫实验结果显示,仔鼠出生后各时间点中、高剂量组T1、T2高于对照组,T3低于对照组,差异均有统计学意义(P<0.001)。结论妊娠期和哺乳期母体高剂量沥青烟染毒可减缓仔鼠体重的正常增长;同时可影响仔鼠海马组织的正常发育并降低其学习记忆能力。

Objective The paper mainly studied the effect of bitumen fume on hippocampus organization＇s coefficient and the influence on learning and memory ability of the offspring of mice during gestation and lactation,and to provide basis for the toxicity mechanism in central nervous system.Methods The pregnant mice were divided randomly into four groups with daily dose of 165、82、41 and 0.0 mg/m3 bitumen fume intake respectively.Each group composed of 10 mice.At the 7th,14th and 21st day after birth,the weight of hippocampus organization＇s coefficient of the offspring was determined.At the 21st day learning and memory ability of the offspring mice was tested by Y-type maze.Results The average body weight of the high dose groups was significantly lower than that of the control group by the end of the 21st day（P0.05）.The offspring mice in high dose group of DEHP had significantly higher level of the weight of hippocampus organization,and its organs＇ coefficient was higher than those in control group at 7th,14th and 21st（P0.01）.The results of Y-type maze demonstrated that T1 and T2 for 21-day old offspring mice in middle-and high-dose groups were significantly lower,as compared with those of the control group（P0.001）.Conclusions Bitumen fume may affect normal weight increase of offspring mice and cause nervous system damage in hippocampus,and results in reduction of learning and memory ability.