共查询到20条相似文献，搜索用时 125 毫秒
1.
苯醚甲环唑应用广泛，在食用农产品中存在残留超标现象，并在不孕女性人群血清和卵泡液中有检出。为探究苯醚甲环唑亚急性经口暴露后对卵巢功能的影响，本研究采用酶联免疫分析方法，测定了分别灌胃给予50、100和200 mg/(kg bw·d)剂量的苯醚甲环唑玉米油溶液后，大鼠血清中孕酮(P)和雌二醇(E2)含量的变化，并在对大鼠卵巢进行苏木精-伊红(HE)染色后，通过光学显微镜观察统计了各级卵泡的数量。结果表明：苯醚甲环唑各剂量暴露组及对照组大鼠卵巢脏器系数均无显著性差异。200 mg/(kg bw·d)高剂量暴露组大鼠血清孕酮水平显著高于对照组(P <0.01),50和100 mg/(kg bw·d)剂量暴露组则与对照组无显著性差异，但均显著低于高剂量暴露组(P <0.05)；各剂量暴露组及对照组之间血清雌二醇水平均无显著性差异。从卵泡的发育情况看，200 mg/(kg bw·d)高剂量暴露组生长卵泡的占比显著高于对照组(P <0.05),50和100 mg/(kg bw·d)剂量暴露组则与对照组无显著性差异。研究表明，200 mg/(kg bw·d)剂量的苯醚甲环唑亚急性经... 相似文献
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氯氰菊酯毒性评价研究 总被引：4，自引：0，他引：4
介绍了联合国粮农组织和世界卫生组织农药残留联席会议(JMPR)以及联合国粮农组织和世界卫生组织食品添加剂联席专家委员会(JECFA)对食品中氯氰菊酯的风险评估历程,并重点阐述了2006年JMPR会议对食品中氯氰菊酯的风险评估的研究进展。主要包括氯氰菊酯、α-氯氰菊酯和ζ-氯氰菊酯的生化资料、毒理学数据和暴露评估资料等。2006年JMPR重新建立了食品中3种氯氰菊酯暴露的健康指导值——每日允许摄入量(ADI)为0~0.02mg/kgb.w.,急性参考剂量(ARfD)为0.04mg/kg b.w.。 相似文献
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采用浸渍法研究了分别取食韭菜、大葱、圆葱和大蒜的韭菜迟眼蕈蚊4龄幼虫对大蒜油、苦参碱和辛硫磷的敏感性,用生化分析法测定了敌敌畏和大蒜油对幼虫体内乙酰胆碱酯酶和主要代谢酶活性的影响.结果表明:大蒜油对取食韭菜、大葱、圆葱和大蒜4龄幼虫的LC50分别为825.14、1202.2、1274.3和1412.4mg/L;辛硫磷分别为0.5437、1.1921、1.7713和1.9224mg/L,两种药剂对取食大蒜和圆葱幼虫的毒力较取食韭菜的差异显著.取食大蒜和圆葱的幼虫较取食韭菜的其体内乙酰胆碱酯酶活力降低,羧酸酯酶的活力明显提高,谷胱甘肽-S-转移酶的活力也有一定提高.寄主植物所含的硫醚类化合物对乙酰胆碱酯酶和代谢酶的诱导或抑制可能是引起药剂敏感性差异的主要原因. 相似文献
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为阐明杀虫剂哌虫啶在SD大鼠体内的代谢动力学过程,以期为进一步的毒理学研究提供依据,采用所建立的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法,测定了单次灌胃给药后大鼠血浆、组织(心、肝、脾、肺、肾、脑、骨骼肌、脂肪)、粪便和尿液样品中哌虫啶的含量,对该药在大鼠体内的吸收、分布和排泄进行了研究。结果表明:哌虫啶750 mg/kg单次经口灌胃给药,雌性大鼠血药浓度-时间曲线下面积(AUC)高于雄性大鼠,且达到峰值时间(T_(max))明显长于雄性大鼠,具有统计学差异,提示在此剂量下,哌虫啶在代谢及毒性效应上可能存在性别差异;在100~750 mg/kg受试剂量范围内,哌虫啶的平均半衰期为4~8 h,表观分布容积为10~30 L/kg,给药剂量与血药浓度-时间曲线下总面积(AUC_(0-inf))呈线性相关性(雄:r=0.996 4,雌:r=0.991 3)。组织分布试验表明,哌虫啶经口给药后,能迅速、广泛地分布到各组织中,并可有效地透过血脑屏障,其中肝、肾中哌虫啶的含量最高,提示其可能主要经肝、肾代谢。排泄试验显示,经尿液及粪便排出的原形哌虫啶含量极低,提示哌虫啶在大鼠体内可能发生广泛的代谢后再排出体外。 相似文献
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叶菌唑在小麦中的残留消解及膳食风险评价 总被引：4，自引：2，他引：2
为评价叶菌唑在小麦中的残留行为及其产生的膳食摄入风险,于北京、安徽及黑龙江进行了1年3地田间试验,建立了叶菌唑在小麦中的残留分析方法,并对我国不同人群的膳食暴露风险进行了评价。样品用乙腈提取,经Florisil固相萃取柱净化,气相色谱-氮磷检测器(GC-NPD)检测,外标法定量。结果表明:在0.02~10 mg/kg的添加水平下,叶菌唑在小麦籽粒和植株中的平均回收率在81%~101%之间,相对标准偏差(RSD)在2.1%~9.1%之间;其在小麦籽粒和植株中的定量限(LOQ)分别为0.02和0.04 mg/kg。叶菌唑在小麦植株中的消解符合一级动力学方程,半衰期为4.9~7.3 d。收获时小麦籽粒中叶菌唑的最大残留量为0.037 mg/kg,低于美国和欧盟设定的最大残留限量(MRL)0.15 mg/kg。针对我国不同人群的膳食摄入及风险评估暴露,风险商值(RQ)在0.001~0.002之间,表明叶菌唑在小麦中的膳食摄入风险较低。 相似文献
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建立了噻唑磷在甘蔗和土壤中的残留分析方法,并在广东和广西2地进行了10%噻唑磷颗粒剂在甘蔗上残留的田间试验,研究了噻唑磷在甘蔗和土壤中的消解动态和最终残留量,并对甘蔗中噻唑磷可能产生的膳食摄入风险进行了评估。甘蔗样本用乙腈提取,氨基固相萃取小柱净化,采用气相色谱-火焰光度检测器 (GC-FPD) 检测。结果表明:在0.01、0.1和1 mg/kg添加水平下,噻唑磷在甘蔗中的平均回收率为83%～84%,相对标准偏差 (RSD) 为2.6%～3.4%;在土壤中的平均回收率为84%～86%,RSD为4.1%～6.7%。噻唑磷检出限 (LOD) 和定量限 (LOQ) 均为0.01 mg/kg。田间试验结果表明:10%噻唑磷颗粒剂在广东和广西甘蔗中的消解不符合一级反应动力学方程,没有显著的消解规律,呈现的特点是浓度由小到大再变小的趋势,施药后14～21 d甘蔗中噻唑磷的残留量达到最大值0.027 mg/kg;噻唑磷在土壤中消解符合一级反应动力学方程,半衰期为8.6～9.6 d,属易降解农药;噻唑磷在甘蔗和土壤中的最终残留量均小于0.01 mg/kg。膳食摄入风险评估结果表明:甘蔗中噻唑磷对人群的急性膳食摄入风险值为225%,急性膳食摄入风险较大,还需进一步结合噻唑磷在人体内的代谢行为等数据进行综合评估;慢性膳食摄入风险值为57%,表明按照推荐剂量施用10%噻唑磷颗粒剂,慢性膳食摄入风险较低,对消费者健康是安全的。 相似文献
7.
呋虫胺在水稻中的残留消解及膳食风险评估 总被引：4，自引：2，他引：2
为评价呋虫胺在水稻中的残留消解行为和产生的膳食摄入风险,分别于2012和2013年在安徽、重庆和广西进行了规范残留试验,建立了高效液相色谱-紫外检测器(HPLC-UV)检测呋虫胺在水稻糙米、稻壳和植株中残留的分析方法,并对我国不同人群的膳食暴露风险进行了评估。样品经乙腈提取、Florisil柱层析净化,高效液相色谱-紫外检测器检测,外标法定量。结果表明:呋虫胺在糙米、稻壳和植株中的定量限(LOQ)均为0.05 mg/kg。在0.05~2 mg/kg添加水平下,呋虫胺的平均回收率在70%~100%之间,相对标准偏差(RSD)在0.5%~6.5%之间。呋虫胺在水稻植株中的消解符合一级动力学方程,半衰期为2.3~4.8 d,距末次施药后7 d糙米中的最大残留量为0.53 mg/kg,低于日本和国际食品法典委员会(CAC)规定的最大残留限量2和8 mg/kg。膳食摄入风险评价结果显示:我国各类人群的呋虫胺国家估计每日摄入量(NEDI)为0.438~1.087 μg/(kg bw·d),风险商值(RQ)为0.002~0.005,表明呋虫胺在糙米中的长期膳食摄入风险较低。 相似文献
8.
在温室中培育烟苗幼苗,至9叶一心时,在第9叶片上用微量注射器分别处理上不同浓度的杀虫剂氟氯氰菊酯、氯氟氰菊酯、溴氰菊酯、毒死蜱、敌敌畏和氧乐果100μl,24h后测定烟草幼苗叶绿素和类胡萝卜素的含量.结果表明,氯氟氰菊酯、氟氯氰菊酯和溴氰菊酯均导致烟草幼苗叶绿素a、叶绿素b、叶绿素总量、类胡萝卜素含量、叶绿素a/b比值上升;氧乐果则完全相反;毒死蜱类似于菊酯类杀虫剂,不同的是叶绿素a/b值较对照有所下降;敌敌畏则导致叶绿素a、叶绿素b、叶绿素总量和类胡萝卜素的含量下降,但叶绿素a/b值较对照有所上升. 相似文献
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丁草胺对土壤微生物数量和酶活性的影响 总被引：17，自引：2，他引：15
在模拟土壤生态系统中研究了丁草胺对土壤微生物数量和酶活性的影响。试验表明,低浓度(2 mg/kg)和中等浓度(4 mg/kg)丁草胺对微生物数量影响不大;而高浓度(10 mg/kg)处理则有明显抑制效应,但在21 d后也基本恢复到对照水平。丁草胺对土壤酸性磷酸酶、碱性磷酸酶、脲酶、蔗糖酶均产生了一定的抑制作用,并随浓度升高而增强,随着时间的延长,抑制作用逐渐消失,酶活性恢复至对照水平。丁草胺对土壤过氧化氢酶的影响与其他酶不同,表现出一定的刺激作用。 相似文献
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Yi Ren Xue-Qin Wei Shuang Wu Wei Dou Jin-Jun Wang 《Pesticide biochemistry and physiology》2008,90(3):196-202
The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in Liposcelis paeta Pearman were investigated in three field populations collected from Nanyang city of Henan Province (NY), Wuzhou (WZ) and Hezhou (HZ) Cities of Guangxi Province, China. The result of bioassay showed that the LC50s of the NY (281.4802 mg/m2) and the WZ (285.0655 mg/m2) to dichlorvos were 1.156-fold and 1.171-fold higher than that of the HZ (243.5197 mg/m2), respectively. Compared to NY population, the activity per insect and the specific activity of AChE in WZ and HZ populations were significantly higher, and significant kinetic differences among the three populations were also observed. The apparent Michaelis–Menten constant (Km) for acetylthiocholine iodide (ATChI) was obviously lower in NY than that in WZ and HZ populations, indicating a higher affinity to the substrate ATChI in the NY population. The affinity to the substrate ATChI between WZ and HZ population was also significantly different. As for Vmax, the values of WZ and HZ populations were significantly greater when compared to that for NY population, suggesting a possible over expression of AChE in the former two populations. The inhibition studies of AChE indicated that paraoxon-ethyl, demeton-S-methyl, carbaryl, and eserine all possessed some inhibitory effects on AChE in L. paeta. The results of I50S suggested that when compared to the other two populations, while AChE from HZ population was less sensitive to paraoxon-ethyl and demeton-S-methyl. The contradiction with the result of the bioassay might be due to the different insecticides used in the bioassay. Although both carbaryl and eserine had excellent inhibitory effects, there was no significant difference among the three populations. The statistical analysis of the bimolecular rate constants (ki) was consistent with the above situation that carbamates expressed remarkable inhibitory effects. It was noticeable that NY population was most sensitive to carbaryl while least to eserine. The differences in AChE among three populations may attribute to the difference in control practices for psocids between Henan and Guangxi Provinces. 相似文献
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田间菜蛾绒茧蜂Cotesia plutellae、颈双缘姬蜂Diadromus collaris和菜蚜茧蜂Diaeretiella rapae对敌敌畏的敏感度及AChE的Ki值远高于其寄主害虫小菜蛾Plutella xylostella和菜缢管蚜Lipaphis erysimi。与对照(25℃)相比,高反应温度(37℃)可显著增高敌敌畏对所测试的5种昆虫AChE的抑制率,而低反应温度(5℃)对5种昆虫AChE的抑制率影响不显著。研究结果还表明,高温对3种寄生蜂AChE的影响明显高于对2种寄主害虫AChE的影响。 相似文献
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In this study, the effects of dichlorvos to lipid peroxidation were investigated at subacute and subchronic periods. Dichlorvos was given with drinking water to Swiss Albino male mice in three dosage levels as 10, 20, and 40 mg/kg b.w. Lipid peroxidation was evaluated by determining the malondialdehyde (MDA) levels in plasma, determining the superoxide dismutase and catalase activities in erythrocytes. The analysis of these enzymes was done in blood samples collected from mice on the days 15 and 45. The results showed that MDA levels increased in dichlorvos treated groups. Actually MDA levels in control and dichlorvos treated groups were determined (as nmol/ml) 10.49, 13.83, 14.30, and 14.50, respectively, at subacute period; 7.77, 8.15, 10.88, and 12.33, respectively, at subchronic period. Catalase activity in erythrocytes decreased at subacute and subchronic periods in dichlorvos treated groups. At subacute period CAT activities were determined (as k/mg Hb) in control and dichlorvos treated groups, 563.45, 532.11, 524.76, and 497.08, respectively; 660.53, 588.84, 525.85, and 512.01, respectively, at subchronic period. When subacute and subchronic periods were compared with each other; it was shown that SOD and CAT activities increased at subchronic period. 相似文献
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药剂对小菜蛾抗性及敏感品系乙酰胆碱酯酶抑制作用比较 总被引：5，自引：1，他引：4
采用浸叶法测定了云南通海、元谋和澜沧的小菜蛾plutella xylostella田间种群对常用杀虫剂的抗药性。结果表明,云南上述地区小菜蛾田间种群对各类杀虫剂均产生了不同程度的抗性。对有机磷类药剂的抗药性为1.74~31.1倍;对菊酯类药剂的抗药性为7.41~764倍;对阿维菌素类药剂则产生了 5.60~4.06×104倍的抗性。通过离体和活体试验测定了药剂对小菜蛾头部乙酰胆碱酯酶(AChE)的抑制作用。敌敌畏和灭多威对通海抗性品系AChE离体和活体内的抑制中浓度(I50)分别是敏感品系的209、26.5倍和2.21、2.16倍;敌敌畏对通海小菜蛾种群的离体和活体内抑制中时间(IT50)小于敏感品系,分别是敏感品系的0.32和0.17倍;而灭多威对通海小菜蛾种群的离体和活体内抑制中时间(IT50)则大于敏感品系,分别是敏感品系的1.37和1.74倍。 相似文献
16.
Soha Basiri 《Pesticide biochemistry and physiology》2007,89(2):124-129
The aim of this study was to examine whether Satureja khuzestanica (Lamiaceae) essential oil (SKEO) might have protective effects on toxicity of malathion, a commonly used organophosphorus (OP), by measuring the activities of hepatic cells mitochondrial glycogen phosphorylase (GP) and phosphoenolpyruvate carboxykinase (PEPCK) activities and blood levels of glucose and acetylcholinesterase (AChE) in rats. Malathion (20 mg/kg/day) and SKEO (225 mg/kg/day) were administered alone or in combination by intragastric intubation for 28 days. Treatment by malathion increased blood glucose as measured at days 18 and 28 of treatment. Malathion inhibited erythrocyte AChE and increased hepatic cells GP and PEPCK activities. Coadministration SKEO resulted in restoration of malathion-induced changes in hepatic cells GP and PEPCK activities and levels of blood AChE and glucose. It is concluded that SKEO interferes with malathion-induced stimulation of hepatic cells glycogenolysis and gluconeogenesis through its antioxidant potential and increasing AChE activity. 相似文献
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采用菌丝生长速率法测定了7种杀菌剂对蘑菇褐腐病菌Mycogone perniciosa Magn.的室内毒力及其中5种杀菌剂对双孢蘑菇Agaricus bisporus的室内安全性,并通过田间小区试验评价了其中6种杀菌剂对蘑菇褐腐病的药效及对双孢蘑菇的安全性。室内测定结果表明:多菌灵、咪鲜胺、噻菌灵、百菌清、苯醚甲环唑及戊唑醇对蘑菇褐腐病菌的毒力均较强,EC50值分别为0.036 9、0.024 5、0.296、0.136、0.036 0和0.058 1 mg/L,福美双毒力较弱,EC50值为88.0 mg/L;多菌灵和百菌清对双孢蘑菇较安全,苯醚甲环唑、戊唑醇及福美双对其有药害风险。田间试验结果表明:按有效成分质量分数计,50%多菌灵可湿性粉剂（WP）250、500和1 000 mg/kg,50%咪鲜胺锰盐WP 333、266和200 mg/kg,75%百菌清WP 375 mg/kg对蘑菇褐腐病的防效较好,且对双孢蘑菇生长无显著影响;而采用43%戊唑醇悬浮剂（SC）143.3、86.0 mg/kg防治褐腐病时,双孢蘑菇的减产率分别为20.54%和13.19%,采用10%苯醚甲环唑可分散粒剂（WG）33.3 mg/kg时,减产率为4.73%,表明这2种杀菌剂对双孢蘑菇的安全性较差,不宜用于防治蘑菇褐腐病;50%福美双WP 1 000 和 500 mg/kg均会造成蘑菇出菇推迟,而166.7 mg/kg的防效较差,因此也不宜用于防治蘑菇褐腐病。 相似文献
18.
三种植物次生物质对B型烟粉虱羧酸酯酶活性及其对药剂敏感度的影响 总被引：1，自引：1，他引：0
采用人工饲料添加法,研究了不同浓度的槲皮素、2-十三烷酮和葫芦素B 3种植物次生物质对B型烟粉虱Bemisia tabaci羧酸酯酶(CarE)活性的影响,同时比较研究了用3种植物次生物质处理后敌敌畏、脱叶磷、灭多威、乐果和氧乐果5种药剂对CarE 的抑制中浓度(I50)的变化。结果表明: 0.01~1.0 mg/mL的槲皮素对B型烟粉虱成虫CarE活性均具有明显的诱导增加作用,最高为对照的4.32倍; 0.1和0.5 mg/mL的2-十三烷酮处理使CarE活性比对照分别下降了22%和58%; 0.75~30.0 mg/L的葫芦素B对烟粉虱CarE活性均表现为抑制作用;用1.0 mg/mL的槲皮素处理24 h后,敌敌畏和脱叶磷对烟粉虱CarE的I50值分别增加为对照的20.05和3.16倍; 3.75 mg/L 的葫芦素B处理后,敌敌畏和灭多威对CarE 的I50值分别增加为对照的25.94、2.45倍; 1.0 mg/mL的2-十三烷酮处理后敌敌畏、脱叶磷和乐果对CarE 的I50值分别降低了89%、83%和90%。 相似文献
19.
为了明确Cd与Zn复合胁迫对麦长管蚜Sitobion avenae(Fabricius)生长发育与繁殖的影响,在室内采用不同含量Cd~(2+)与Zn~(2+)溶液交互处理土壤-小麦-麦长管蚜系统,利用特定年龄生命表研究在不同含量Cd与Zn复合胁迫下麦长管蚜生命参数及繁殖的变化规律。结果表明,Cd、Zn以及Cd与Zn交互作用均极显著影响麦长管蚜的生命参数与繁殖,其中Zn对麦长管蚜种群参数的影响最大。在40 mg/kg Cd与400 mg/kg Zn复合胁迫下,麦长管蚜种群的内禀增长率、净增值率显著高于单一Cd胁迫;但不同含量Cd与800、1 600 mg/kg高含量Zn或不同含量的Zn与120、240 mg/kg高含量Cd复合胁迫时,其内禀增长率与净增值率却逐渐下降;其平均世代周期在复合胁迫条件下显著低于单一Cd胁迫。生殖力曲线面积的变化规律与种群参数的变化规律相同,推测40 mg/kg和400 mg/kg分别为Cd与Zn复合胁迫的关键含量。研究表明,低含量Cd与Zn复合胁迫能显著促进麦长管蚜生长发育,而高含量Cd与Zn复合胁迫并不能促进麦长管蚜的生长发育。 相似文献
20.
BACKGROUND: Carbofuran is a carbamate insecticide that inhibits AChE. Although toxic by ingestion in mammals, it has low dermal toxicity, with relatively few confirmed worker illnesses. This risk assessment describes its time of onset, time to peak effect and time to recovery in rats using brain AChE inhibition in acute and 21 day dermal studies; in vitro rat/human relative dermal absorption for granular (5G) and liquid (4F) formulations; occupational exposure estimates using the Pesticide Handlers' Exposure Database and Agricultural Handlers' Exposure Database (PHED/AHED). RESULTS: The point of departure for acute risk calculation (BMDL10) was 6.7 mg kg?1 day?1 for brain AChE inhibition after 6 h exposure. In a 21 day study, the BMDL10 was 6.8 mg kg?1 day?1, indicating reversibility. At 75 mg kg?1 day?1, time of onset was ?30 min and time to peak effect was 6–12 h. Rat skin had ca tenfold greater dermal absorption of carbofuran (Furadan® 5G or 4F) than human skin. Exposure estimates for 5G in rice and 4F in ten crops had adequate margins of exposure (>100). CONCLUSION: Rat dermal carbofuran toxicity was assessed in terms of dose and time‐related inhibition of AChE. Comparative dermal absorption in rats was greater than in humans. Worker exposure estimates indicated acceptable risk for granular and liquid formulations of carbofuran. Copyright © 2011 Society of Chemical Industry 相似文献