大鼠毒死蜱重复染毒后血清胆碱酯酶活性及其变化规律

目的了解毒死蜱(Chlorpyrifos,CPF)重复染毒后大鼠血清中乙酰胆碱酯酶(AChE)和丁酰胆碱酯酶(BuChE)在不同时间点的活性情况,并分析两酶活性关系。方法将60只成年雌性SD大鼠按体重随机分成5组,每组12只,分别为毒死蜱组:2.50、5.00、10.00、20.00mg/kg及1个正常对照组。连续灌胃染毒10d,在第2、4、7和11d分别对部分动物(每次每组3只)收集血液样本,测定AChE、BuChE活性。结果血清中AChE、BuChE活性随着毒死蜱剂量、染毒时间增加而降低,呈现一定程度上的相关性。血清中AChE活性和BuChE活性呈现出正相关性(r=0.872,P0.01),随着重复染毒两酶变化趋势相同,但BuChE抑制程度更大(P0.01)。结论 10d重复染毒后AChE、BuChE抑制程度会增加。血清BuChE可考虑作为有机磷农药暴露的标志物。

Analysis of cholinesterases activity and their variation in rat serum upon repeated exposure to chlorpyrifos

Objective To study activity of acetylcholinesterase （ACHE） and butyrylcholinesterase （BuChE） in rat serum at different time points after repeated exposure to chlorpyrifos（CPF） ;to analyze relationship of the activity of AChE and BuChE. Methods 60 female adult SD rats were randomly divided into 5 groups by weight, 12 rats in each group：4 chlorpyrifos dose groups （dosage：2.50,5.00,10.00,20.00 mg/kg） and 1 control group. Rats in all groups were successively treated with CPF for 10 days by gavage. Blood samples of 3 rats in each group were collected at 2~d,4th,7th and 11th d , activity of AChE and BuChE was determined. Results Serum AChE and BuChE activity decreased upon prolonged exposure time or when chlorpyri- fos dosage increased in a dose-dependent manner. Activity of AChE and BuChE in serum showed a positive correlation （r= 0. 872, P〈0.01）, with similar trend upon repeated exposure. However, BuChE demonstrated greater inhibition effect com- pared to AChE （P〈0.01）. Conclusion Inhibition of AChE and BuChE increased upon 10 d repeated exposure to CPF. Serum BuChE can be considered as a sensitive indicator for organophosphorus pesticide exposure.