寄主植物对棉铃虫体内解毒酶活性的影响

通过离体酶活性测定 ,研究取食小麦、豌豆等寄主植物和人工饲料对棉铃虫羧酸酯酶、谷胱甘肽 S-转移酶和乙酰胆碱酯酶活性的影响。结果表明取食不同寄主植物的棉铃虫体内羧酸酯酶活性不仅存在量的差异 ,而且存在质的差异 ,寄主植物对棉铃虫谷胱甘肽 S-转移酶、乙酰胆碱酯酶活性有显著影响     

白背飞虱羧酸酯酶与乙酰胆碱酯酶的体躯与亚细胞分布特征

白背飞虱Sogatella furcifera(Horváth)羧酸酯酶(CaE)和乙酰胆碱酯酶(AchE)的体躯及亚细胞分布特征研究结果表明，若虫头、胸、腹部中CaE活性分别占50.8%，26.0%和23.2%，雌成虫各占33.0%，23.5%和43.5%，雄成虫各占26.5%，23.2%和50.3%。若虫、雌雄成虫的AchE活性均主要分布于头部，各占总活性的87.7%，71.1%和74.7%。差速离心结果表明，该飞虱CaE主要位于胞质溶胶层中，其活性占57.0％～66.9%；AchE活性在胞质溶胶层中仅占5.8%～17.0%，而62.8%～76.9%的活性则分布于线粒体层、细胞核和细胞碎片层中。最后就上述两种酶在细胞中的存在形式作了讨论。     

甲氰菊酯对尼罗罗非鱼组织乙酰胆碱酯酶、谷丙转氨酶和谷胱甘肽活性的影响

用急性染毒法研究6种浓度(0、0.4、0.6、0.8、1.0、1.5 μg/L)的甲氰菊酯对(34.89±9.99)g的尼罗罗非鱼(Tilapia nilotica)分别处理6、12、24、48、96 h后,其组织内乙酰胆碱酯酶(AChE)、谷丙转氨酶(GPT)和谷胱甘肽( GSH)的动态变化.结果显示:AChE活性在...     

不同地理种群甘薯茎线虫乙酰胆碱酯酶对抑制剂的敏感性

用改进的Ellman方法测定了河北省昌黎、涿州、卢龙和抚宁四个不同地理种群甘薯茎线虫Ditylenchus destructor的乙酰胆碱酯酶（AChE）的生化特性及其对抑制剂涕灭威和毒扁豆碱的敏感性差异。结果表明：甘薯茎线虫AChE至少存在两种类型，一种类型对毒扁豆碱的IC50值小于10^-6mol／L，另一种类型大于10^-4mol／L。当抑制剂毒扁豆碱浓度为10^-6～10^10mol／L、涕灭威浓度为10^-5～10^10mol／L时，甘薯茎线虫昌黎种群AChE的敏感性抑制率明显高于涿州、抚宁、卢龙三地的甘薯茎线虫种群AChE的抑制率。各地种群AChE对抑制剂敏感性差异是由于甘薯茎线虫AChE的多态性和各分子型综合性改变的结果。     

甲酸乙酯对米象乙酰胆碱酯酶和羧酸酯酶的影响

报道了甲酸乙酯对米象[Sitophilus oryzae(Linnaeus)]乙酰胆碱酯酶(AChE)和羧酸酯酶(CarE)的活性影响,甲酸乙酯对米象表现出很高的毒力,25℃下熏蒸处理24 h的LC₅₀为28.65μL/L。亚致死剂量的甲酸乙酯可以使米象成虫体内AChE的比活力显著下降,用20μL/L的浓度处理24 h,AChE的比活力由15.684 nmol/mg.min下降至9.530 nmol/mg.min;酶动力学研究表明,甲酸乙酯可使米象成虫体内AChE的K_m值明显增加。对于羧酸酯酶,在活体条件下表现为先抑制后激活的规律,离体条件下则主要表现为抑制作用,且随着药剂浓度的增大抑制率也增大。     

不同地理种群棉蚜三种关键性酶活差异及其与抗性相关性

【目的】研究新疆不同地理种群棉蚜3种酶的活性及抗药性的差异。【方法】测定新疆库尔勒、五家渠、石河子、奎屯、哈密地区棉蚜和实验室敏感种群羧酸酯酶、谷胱甘肽-S-转移酶、乙酰胆碱酯酶活性,并分析3种酶活性与吡虫啉抗性之间的关系。【结果】库尔勒、五家渠、石河子、奎屯和哈密地区乙酰胆碱酯酶和谷胱甘肽-S-转移酶的比活力比值分别为4.2、2.7、2.3、2.5、2.1倍和2.3、1.5、1.3、2.5、2.1倍,差异显著（P<0.05）;羧酸酯酶比活力比值为6.5、4.2、3.4、2.7、1.2倍,除哈密地区相对接近外,其余地区均明显高于1.0,差异显著（P<0.05）,2种棉蚜关键解毒酶和1种神经传导关键性酶与抗药性之间存在一定相关性。【结论】各地理种群棉蚜3种酶活性均显著高于敏感种群（P<0.05）,且彼此之间存在差异性,羧酸酯酶在棉蚜感受到吡虫啉杀虫剂胁迫时极有可能起到重要作用。     

Stimulation of acetylcholinesterase activity by triiodothyronine in the brain of Singi fish,Heteropneustes fossilis (Bloch)

Three consecutive days of injections of triiodothyronine (T₃)(0.038, 0.075, 0.15 and 1.54 nmoles/g) significantly elevated the acetylcholinesterase (AchE) activity in the brain of Singi fish, Heteropneustes fossilis (Bloch). The higher doses of 0.075, 0.15 and 1.54 nmoles of T₃/g induced a greater increase in enzyme activity than 0.038 nmoles/g. A T₃ dose of 0.019 nmoles/g was found to be ineffective. The T₃ action on AchE activity was blocked by cycloheximide. Thiourea treatment for 30 days decreased the AchE activity below the control level. This reduced level of the enzyme activity was brought back even above the control level by T₃ injections. It is, therefore, suggested that thyroid hormone is involved in the sustenance of AchE activity in fish brain.     

Characterization of acetylcholinesterase and its molecular forms in organs of five freshwater teleosts

The activity and molecular forms of acetylcholinesterase (AChE, EC 3.1.1.7) were characterized in the brain, heart, white skeletal muscle and liver of the Siberian sturgeon (Acipenser baeri), European eel (Anguilla anguilla), wels (Silurus glanis), common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix), belonging in four families. The brain had the highest (between 183.2±10.6 and 1361.2±189.7 mU mg^-1 protein and between 4.7±0.4 and 23.5±2.7 U g^-1 wet tissue) and the liver the lowest (between 25.3±1.9 and 126.5±22.7 mU mg^-1 protein and between 1.0±0.1 and 4.5±0.5 U g^-1 wet tissue) activity in all these fish, with the exception of the wels, where the heart contained the smallest amount of AChE (26.2±7.5 mU mg^-1 protein and 1.2±0.3 U g^-1 wet tissue). The highest tissue AChE activity was found in the carp and lowest in the sturgeon. The solubility properties and molecular forms of AChE in the four tissues were studied by extraction in high-salt medium (1.0 M NaCl) with and without the detergent Triton X-100 (0.5%, v/v). The proportions of detergent-soluble (DS) and salt-soluble (SS) forms of AChE varied considerably from one species to another, but a general tendency could be observed: the proportion of DS AChE was generally higher in the brain (between 70.4±4.1 and 82.5±1.2%) and lower in the heart (between 12.0±2.0 and 51.3±2.3%) and skeletal muscle (between 16.0±2.0 and 64.4±0.7%). Velocity sedimentation centrifugation revealed that most tissues contained the G₄ or A₄ form. Three tissues (brain, heart, and liver) of the Siberian sturgeon contained a relatively high proportion of the G1 form (between 24.3±2.4 and 28.6±4.9%), while the skeletal muscle of the wels contained only the most complex type of AChE, i.e., A₁₂. Amongst the tissues studied, the brain and liver mostly contained amphiphilic globular forms of the G₄ type, while the heart and skeletal muscle were rich in asymmetric forms (A₄ and A₁₂). It was concluded that the differences revealed in the activities of AChE and in the distribution of its molecular forms may be connected with the variation in behavioral habits (feeding and swimming patterns), and the developmental stage of the nervous system.     

丹皮、泽泻混和物对黄粉虫幼虫体内蛋白酶和乙酰胆碱酯酶活性的影响

以中药材丹皮、泽泻及其混和物为饲料对黄粉虫幼虫体内蛋白酶和乙酰胆碱酯酶活性的影响进行了研究结果表明:丹皮能显著抑制幼虫体内的蛋白酶活性,在处理5d后,也抑制幼虫的乙酰胆碱酯酶活性;而丹皮泽泻饮片混和物与泽泻相比,幼虫体内蛋白酶和乙酰胆碱酯酶活性没有受到显著影响,但与面粉相比,在一定时间内幼虫的蛋白酶活性受到了影响,说明丹皮影响了幼虫对蛋白质的水解作用,随着时间的延长对幼虫的神经传导也有影响;而混和物在一定时间内可影响幼虫对蛋白质的水解作用而对幼虫的神经传导没有显著影响     

Evidence for occurrence of an organophosphate-resistant type of acetylcholinesterase in strains of sea lice (Lepeophtheirus salmonis Krøyer)

Acetylcholinesterase (AChE) is the target of a major pesticide family, the organophosphates, which were extensively used as control agents of sea lice on farmed salmonids in the early 1990s. From the mid‐1990s the organophosphates dichlorvos and azamethiphos were seriously compromised by the development of resistance. AChE insensitive to organophosphate chemotherapeutants has been identified as a major resistance mechanism in numerous arthropod species, and in this study, target‐site resistance was confirmed in the crustacean Lepeophtheirus salmonis Krøyer isolated from several fish‐farming areas in Norway and Canada. A bimolecular rate assay demonstrated the presence of two AChE enzymes with different sensitivities towards azamethiphos, one that was rapidly inactivated and one that was very slowly inactivated. To our knowledge this is the first report of target‐site resistance towards organophosphates in a third class of arthropods, the Crustacea. Copyright © 2004 Society of Chemical Industry