乐果亚慢性染毒对大鼠自发活动的影响  

Changes of spontaneous activities in rats subchronically exposed to dimethate

作　　者：姚新民[1] 吴强恩[1] 常秀丽[1] 姜楠[1] 班婷婷[1] 邵春风[1] 周志俊[1] 

机构地区：[1]复旦大学公共卫生学院劳动卫生教研室-公共卫生安全国家教育部重点实验室,上海200032

出　　处：《复旦学报（医学版）》2008年第2期212-215,共4页Fudan University Journal of Medical Sciences

基　　金：国家自然科学基金项目(30571554);上海市曙光学者计划基金课题

摘　　要：目的探讨有机磷农药乐果90d染毒对大鼠自发活动的影响。方法48只健康雄性SD大鼠随机分成4组,分别使用生理盐水(对照),5mg/kg(低剂量)、10mg/kg(中剂量)和20mg/kg(高剂量)的乐果灌胃给药,每周染毒5d,每天1次,实验周期90d。定期尾静脉采血,测定全血AChE活性,实验结束时随机取半数动物,用DigBehv-LR型自发活动视频分析系统测定其自发活动;其余动物均断头处死,测定脑AChE活性。结果实验期间,各乐果染毒组动物全血AChE活性明显抑制,实验后期有所恢复。实验结束时,低、中、高剂量组脑组织AChE活性分别为对照组的78%、63%和42%,存在剂量-效应关系。大鼠自发活动测试结果显示,随染毒剂量的增加,低、中、高剂量大鼠的总路程、活动时间、平均速度有下降趋势,而休息时间有升高趋势。其中高剂量组的变化最为明显,总路程、活动时间、平均速度同对照组相比分别下降了54.6%、55.3%、54.7%,而休息时间增加了41.3%,同对照组相比都有显著性差异(P<0.05)。对大鼠自发活动指标和全血及脑AChE活性的相关性进行分析,发现染毒大鼠的总路程、活动时间、平均速度和休息时间和脑AchE活性呈显著相关(P<0.05),而与全血AchE活性在统计学上无相关性(P>0.05)。结论乐果亚慢性染毒会使大鼠自发活动降低,这可能同脑组织AChE活性受到长期抑制有关。Objective To investigate the changes of spontaneous activities in rats challenged with dimethoate for 90 days.Methods Dimethoate at the doses of 0（saline vehicle）,5,10 and 20 mg/kg were administered by gavage to rats 5 times a week for 90 days.Both the body weights and food consumption of the rats were recorded.Additionally,the activities of acetylcholinesterase（AChE）in whole blood were determined with UV spectrophotometry regularly during the experimental course.The locomotor activities were evaluated in openfield test at the end of the study.The brain AChE activities were also determined after decapitation of the rats.Results The activities of whole blood AChEs decreased significantly during the experimental period（P〈0.05）.Similarly,significant depression of AChEs was observed in rat myelencephalon as compared to the control group at the end of the test（P〈0.01）.The total course,activity time and mean velocity of the dosed groups were decreased.The rest time of the dosed groups was increased.Significant changes were found in high dose group as compared to that of control.Furthermore,the behavioral alterations mentioned above were statistically correlated with the brain AChE activities in rats.Conclusions The subchronic exposure of dimethoate could decrease the locomotor activities in rats which might due to the long-term cholinergic lesions in rat brain.

关 键 词：乐果 大鼠 自发活动 乙酰胆碱酯酶 

分 类 号：TQ456.3[化学工程—农药化工]