【摘要】 目的观察乐果染毒对大鼠大脑纹状体和血清中多巴胺-β-羟化酶(dopamine--βhydroxylases,DβH)活性变化的影响,对乐果中毒机制作进一步的探讨。方法 56只雄性SD大鼠随机分为对照组(生理盐水,n=8)和乐果染毒低(38.9mg/kg,n=8)、中(83.7mg/kg,n=8)和高(180mg/kg,n=32)3个剂量组,腹腔一次注射染毒。高剂量组大鼠分别在给药后0.5、2、8、24h断头处死取血制备血清待测,并分离脑组织纹状体,生理盐水匀浆待测。其他组动物在给药后2h断头处死,同样方式取样供分析。利用DβH将酪胺代谢为真蛸胺原理检测DβH活性。另取正常大鼠血清和纹状体匀浆,体外乐果染毒,观察其对DβH抑制状况。结果给予不同剂量乐果对大鼠纹状体和血清DβH活性均有抑制作用,并随剂量增加而加深,存在剂量-效应关系(r=-0.996 7,P<0.05)。乐果高剂量(180mg/kg)染毒后大鼠大脑纹状体和血清中DβH活性与对照组相比,在不同时程观察点差异均有统计学意义(P<0.05),随时程增加抑制也加深,24h内时程效应关系(P<0.05)明确。体外乐果对纹状体和血清DβH活性均有抑制作用,并随剂量增加而加深,有剂量-效应关系(r=-0.891 2,P<0.05),但在高浓度有饱和现象。结论大鼠大脑纹状体和血清中DβH水平有随染毒剂量和时程的增加而抑制加深的趋势,存在剂量效应和时程效应关系。更多还原

【Abstract】 Objective To observe the effect of dimethoate(DM) on dopamine-β-hydroxylases(DβH) activity in rat serum and striatum,and to further discuss the mechanism of dimethoate-induced poisoning. Methods Fifty-six male SD rats were randomized into control group(saline,n=8) and DM-treated groups with 3 dosages of low(38.9 mg/kg,n=8),medium(83.7 mg/kg,n=8) and high(180 mg/kg,n=32) level,respectively.A poisonous injection was given into celiac.The rats in group of high-level DM treated were decollated respectively at 0.5,2,8,and 24 hours after administrating DM to collect blood and brain striatum samples.The rats in the other groups were decollated at 2 hours.Serum and saline homogenate of striatum were prepared for measurement of DβH activity.Moreover,the inhibitive effect of DM on serum and striatum DβH activity in vitro were also observed. Results The levels of DβH activity in rat serum and striatum were decreased by administrating dimethoate in dose-dependent manners(r=0.996 7,P<0.005).Compared with controlled group,DβH activities in serum and striatum of 180 mg/kg dimethoate rats differed at different time points and showed a significant decrease over time(P<0.05).The time-effect relationships were definied in 24 h(r=-913 4,P<0.05).The inhibition effect also existed in vitro with a dose-response relationship(P<0.05),however,there was saturation effect at high dose. Conclusions These findings indicate that DM-induced toxic effects can alter DβH activity in rat serum and striatum,suggesting that some non-cholinergic mechanisms are involved in DM intoxication.更多还原