中文摘要：

目的比较敌敌畏对大鼠乙酰胆碱酯酶抑制作用的基准剂量（BMD）和未观察到有害作用水平（NOAEL）。方法将80只健康清洁级成年雌性sD大鼠按体重随机分为8组，分别为对照（蒸馏水）组和0．22、0．44、0．88、1．75、3．50、7．00、14．00111g／kg敌敌畏染毒组，采用灌胃方式进行染毒，染毒容量为10ml／kg，每天1次，连续染毒21d。测定大鼠脑组织海马、皮质和血清中的乙酰胆碱酯酶活力，并计算BMD值和NOAEL值。结果与对照组比较，7．00～14．00mg／kg敌敌畏染毒组大鼠脑组织海马和3．50～14．00mg／kg敌敌畏染毒组大鼠脑组织皮质及1．75～14．00mg／kg敌敌畏染毒组大鼠血清中的乙酰胆碱酯酶活力均下降，差异有统计学意义（P〈0．05）；且大鼠血清乙酰胆碱酯酶活力随敌敌畏染毒剂量的升高而下降。敌敌畏经口灌胃对大鼠脑组织皮质、海马和血清的BMD分别为1．80、0．81、0．51mg／kg，95％可信区间下限（BMDL）分别为1．42、0．44、0．30mg／kg；NOAEL分别为3．5、1．75、0．88mg／kg。结论BMD法比NOAEL法得到的安全参考剂量更为保守，能为人群提供更广泛的保护。

英文摘要：

Objective To compare dichlorvos＇s BMD and NOAEL in the inhibition effect of aeetylcholinesterase in rats. Methods A total of 80 adult female SD rats were randomly divided into eight groups,one control group （distilled water） and seven dose groups （0.22,0.44,0.88,1.75,3.50,7.00 and 14.00 mg/kg body weight）. After exposure through oral garage with 10 ml/kg for 21 consecutive days, acetylcholinesterase activities in the rat hippocampus,cortex and serum were determined,and the BMD values and NOAEL values were calculated. Results Compared with the control group, activity of acetylcholinesterase in hippocampal tissue, cortex and serum significantly decreased with a dose-dependent manner in the following groups, including dichlorvos exposure groups with the concentrations of 7.00-14.00 mg/kg, 3.50-14.00 mg/kg and 1.75-14.00 mg/kg. Calculated BMD values were 1.80,0.81,0.51 mg/kg,BMDL values were 1.42,0.44 and 0.30 mg/kg,NOAEL values were 3.50, 1.75 and 0.88 mg/kg. Conclusion The BMD method recommended a more conservative safe conference dose than the NOAEL method, which can provide protection for general population.