溴甲烷对大鼠体格发育和空间记忆发育的影响

Effects of methyl bromide on physical and space memory development in rats

目的 观察溴甲烷对大鼠体格发育和空间记忆发育的影响 ,探讨其中枢机制。方法 3 0只幼年Wistar大鼠随机分为正常对照组和溴甲烷染毒组 ,每组 15只。染毒组经呼吸道吸入 ( 164 2± 2 5 6)mg/m3 1h ,7d后重复吸入一次溴甲烷染毒 ,4周后分别测定两组大鼠体重、血清生长激素水平 ;用水迷宫方法观察溴甲烷对大鼠空间记忆能力的影响。结果 染毒 4周后 ,对照组大鼠体重增长量为 ( 80 99± 2 6 11)g ,染毒组大鼠体重增长明显放缓为 ( 3 9 0 9±9 2 2 )g (P <0 0 1) ;血清生长激素水平对照组为 ( 2 45± 0 2 2 )ng/ml ,染毒组降低为 ( 1 43± 0 49)ng/ml (P <0 0 1) ;水迷宫测试显示其平均逃逸潜伏期在第 5天对照组为 ( 2 2 1± 12 0 )s ,而染毒组延长为 ( 4 4 6± 15 8)s (P <0 0 5 ) ;搜索实验显示染毒组大鼠穿过平台所在位置的次数 (PC)为 ( 3 9± 1 3 ) ,明显少于对照组 ( 6 1± 3 2 ) (P <0 0 5 )。结论 溴甲烷对大鼠的生长发育具有抑制作用 ,对学习记忆等脑的高级神经活动具有明显的损害作用。

Objective To study the effects of methyl bromide on physical and space memory development in rats and its mechanisms.Method Thirty young Wistar rats were randomly divided into a group exposed to methyl bromide(15 rats)and a control group(15 rats).Rats in the former group were exposed to methyl bromide(1 642±256)mg/m 3 for 1 h via inhalation and re-exposed 7 days later.Weight and serum level of growth hormone were measured for the rats,and their space memory was observed by water maze test 4 weeks after exposure.Result Weight was gained by(80.99±26.11)g in the control rats and by(39.09±9.22)g in the exposed ones,respectively,P<0.01.Serum level of growth hormone was(2.45±0.22)ng/ml in the control rats and(1.43±0.49)ng/ml in the exposed ones,respectively,P<0.01.Results of water maze test showed that average escape latency prolonged signifcantly in the exposed rats[(44.6±15.8)s]than that in the control ones[(22.1±12.0)s],P<0.05,and number of PC(pass circles) decreased significantly in the exposed rats(3.9±1.3)compared with the control ones(6.1±3.2),P<0.05.Conclusion Methyl bromide could inhibit physical development in rats and could damage their higher nervous activity,such as ability of learning and memory,etc.,possibly by inhibiting the activities of nervous and endocrine systems.