Insect juvenile hormones: Induction of detoxifying enzymes in the housefly and detoxication by housefly enzymes

The cecropia juvenile hormone and three of its analogs were compared as inducers of microsomal epoxidase, O-demethylase, and DDT dehydrochlorinase in the housefly, Musca domestica L. The compounds were the cecropia juvenile hormone, methoprene, hydroprene, 6,7-epoxy-3,7-diethyl-1-[3,4-(methylenedioxy)phenoxy]-2-octene, and piperonyl butoxide, a well known insecticide synergist. The compounds were administered by feeding at levels up to 1% in the diet for 3 days to 1-day-old female adults. Enzymes were then prepared and assayed for their activity using heptachlor, p-nitroanisole, and DDT as substrates.There was approximately a twofold increase in the microsomal oxidases and a 50% increase in DDT dehydrochlorinase after the treatment with the cecropia juvenile hormone, while methoprene had some activity as an inducer of the epoxidase (30% increase) but no activity in the case of the O-demethylase or the dehydrochlorinase. Hydroprene had no effect on any of the enzyme systems, while 6,7-epoxy-3,7-diethyl-1-[3,4-(methylenedioxy)phenoxy]-2-octene was an inhibitor of the two microsomal oxidases. The latter compound and piperonyl butoxide were strong inducers of DDT dehydrochlorinase, causing approximately twofold increases in the activity of this enzyme.There was evidence that the microsomal preparations were able to metabolize and inactivate methoprene and hydroprene, the action being oxidative in the case of methoprene and both oxidative and hydrolytic in the case of hydroprene. The oxidative metabolism of the two juvenile hormone analogs by the microsomal preparations was inducible by the cecropia juvenile hormone and by phenobarbital and dieldrin.     

蓖麻提取液对甜菜夜蛾幼虫解毒酶活性的影响

为探讨植物提取液对甜菜夜蛾解毒酶系活性的影响效应,采用浸渍法测定了不同浓度蓖麻碱(3.80、1.90、0.95、0.48和0.24g/L)对甜菜夜蛾幼虫碱性磷酸酯酶(AKP)、酸性磷酸酯酶(ACP)和谷胱甘肽S-转移酶(GSTs)活性的影响。结果表明:与清水对照组相比,不同浓度处理48h和72h对AKP的抑制作用均达到显著水平,而3.80g/L处理24h即可显著抑制AKP活性;与对照组相比,不同浓度蓖麻碱处理72h均会显著降低其ACP活性,而浓度大于0.24g/L时处理24h和48h即可显著降低ACP活性;蓖麻碱处理组GSTs活性在处理后24、48和72h都显著低于对照组,但不同浓度间无显著差异;本研究揭示了蓖麻碱对这3种解毒酶均有较强的抑制作用,且抑制作用随蓖麻碱浓度升高和作用时间延长而增强。     

松油烯-4-醇对家蝇体内几种酶系的影响

测定了松油烯-4-醇对家蝇成虫的毒杀活性及其体内几种酶系活性的影响.结果表明:松油烯-4-醇对家蝇具有较强的触杀作用,24h的LD50为23.91μg/虫;对家蝇的致毒症状可明显地分为兴奋、痉挛、麻痹、死亡或复苏等几个阶段;对Na ,K -ATPase具有较强的抑制作用,在兴奋期、痉挛期、麻痹期和复苏期,酶抑制率分别为23.2l%、20.27%、61.84%和58.35%;离体条件下,对Na ,K -ATPase的I50为0.8379×103μg·mL-1;对AChE有一定的抑制作用;可激活酯酶,在复苏期,酶比活力为对照的1.42倍.     

Phenobarbital induction of detoxifying enzymes in resistant and susceptible houseflies

Houseflies, Musca domestica, L., were treated with the drugs phenobarbital and 3-methylcholanthrene to study the effects of these compounds as inducing agents of the microsomal oxidases, heptachlor epoxidase, and p-nitroanisole O-demethylase, and of DDT-dehydrochlorinase. Phenobarbital was active when applied by injection or as part of the diet but inactive when topically applied. The resulting increases in heptachlor epoxidase activity were as much as 25-fold that of the untreated controls. The net increase in enzyme activity after phenobarbital treatment was greater in an insecticide-susceptible strain, WHO-SRS strain, than in a carbamate-resistant strain. However, the phenobarbital induced increases in DDT-dehydrochlorinase were greater, about 2-fold, in the resistant strains than in the susceptible strain.The optimum dose for phenobarbital was 1% in the diet for a period of 3 days. None of the treatments with 3-MC, feeding, injection, exposure to residues, or topical, were effective in induction.     

Host plant stimulation of detoxifying enzymes in a phytophagous insect

The midgut microsomal aldrin epoxidase of variegated cutworm larvae (Peridroma saucia, Hübner) fed bean or peppermint leaves was up to 10 and 45 times more active, respectively, than that of larvae fed a basic control diet. Large increases in oxidase activity and cytochrome P-450 levels also occurred in larvae fed mint plant constituents such as menthol menthone, α-pinene, and β-pinene. Mint-fed larvae were more tolerant of the insecticide, carbaryl, than bean-fed larvae.     

Induction of detoxifying enzymes by allelochemicals and host plants in the fall armyworm

The effect of various plant substances and host plants on the microsomal oxidases and glutathione S-transferase was investigated in the fall armyworm (Spodoptera frugiperda (J. E. Smith)) maintained on a meridic diet. The glucosinolate, sinigrin, and the hydrolytic products of glucosinolates, β-phenylethylisothiocyanate, indole 3-acetonitrile, and indole 3-carbinol, and flavone were found to be potent inducers of the glutathione S-transferase in the armyworm. An 18-fold increase in the transferase activity was observed when larvae were fed a diet containing 0.2% indole 3-acetonitrile for 2 days. These compounds, with the exception of β-phenylethylisothiocyanate which appeared to be inhibitory, also stimulated the microsomal aldrin epoxidase significantly. In all instances, no induction of the microsomal oxidase or glutathione S-transferase was observed by the plant hormones, indole 3-acetic acid and gibberellic acid; the terpenoids, stigmasterol, sitosterol, and β-carotene; the polyphenolic gossypol; and the flavonol, quercetin; some of them were found to be inhibitory. Using corn, potato, and sweet potato as inducers of various microsomal oxidases, it was found that the inducing pattern of the N-demethylase was different from the two epoxidases and O-demethylase. Corn leaves were the most active compared with other aerial parts of corn (silks, developing corn, and husk) in inducing the microsomal oxidase. The microsomal oxidase in the younger larvae appeared to be less inducible by host plants than in the older larvae.     

唑虫酰胺对甜菜夜蛾亚致死效应及解毒酶活性的影响

为明确唑虫酰胺对甜菜夜蛾的亚致死效应以及甜菜夜蛾对唑虫酰胺的生化抗性机制, 本研究在测定10种药剂对甜菜夜蛾室内毒力的基础上, 研究了唑虫酰胺LC10、LC30和LC50浓度对甜菜夜蛾生长繁殖和解毒酶活性的影响及甜菜夜蛾的生化抗性机制。结果表明, 高浓度处理组(LC50)的甜菜夜蛾成虫寿命、羽化率和卵孵化率等均显著低于对照组, 低浓度唑虫酰胺(LC10)诱导了甜菜夜蛾谷胱甘肽 S-转移酶(GST)和羧酸酯酶(CarE)活性的上升, 显著抑制了多功能氧化酶(MFO)的活性;增效试验表明, 增效醚(PBO)和磷酸三苯酯(TPP)对唑虫酰胺有明显的增效作用。抗性种群的CarE、MFO和GST酶活都显著高于敏感种群。综上, 低浓度的唑虫酰胺对甜菜夜蛾的生长发育有显著的抑制作用, MFO、CarE和GST在甜菜夜蛾对唑虫酰胺的抗性中发挥了重要作用。     

氯虫苯甲酰胺亚致死剂量对棉铃虫生长发育和解毒酶活性的影响

在室内采用培养基混药法测定氯虫苯甲酰胺亚致死剂量(LC10、LC25和LC50)对棉铃虫生长发育和体内3种解毒酶系的影响。结果表明:各剂量处理3龄幼虫48h后饲养,各处理组当代(F0)3～6龄幼虫历期均比对照组延长0.2～3.8d,但成虫平均历期比对照组缩短0.8～2.5d,子代(F1)1～6龄幼虫历期均比对照组延长0.2～2.6d,成虫平均历期比对照组缩短0.1～0.5d;各剂量处理后,各处理组F0代3～6龄幼虫和蛹的体重、F1代4～6龄幼虫和蛹的体重均比对照组减轻,且剂量越大,体重减轻越显著;各处理组F0代种群趋势指数分别比对照组下降了16.27%、58.51%和71.17%,F1代分别下降了13.66%、52.61%和66.63%;各处理组F0代3～6龄幼虫体内的羧酸酯酶(CarE)和细胞色素P450O-脱乙基酶(P450-ECOD)比活力均高于对照组,其中6龄幼虫这两种酶比活力分别比对照组提高了5%～16%和23%～66%,但各处理组谷胱甘肽硫转移酶(GSTs)比活力均低于对照组,其中6龄幼虫GSTs比活力分别比对照组降低了16.23%、58.51%和71.17%。表明在LC10～LC50剂量范围内,氯虫苯甲酰胺处理棉铃虫3龄幼虫的亚致死剂量越高,其生长发育受抑制越显著,P450-ECOD和CarE比活力上升越高,GSTs比活力下降也越大。     

茚虫威对草地贪夜蛾的毒力及解毒酶的诱导作用

茚虫威对鳞翅目害虫幼虫具有卓越的杀虫活性,是替代传统杀虫剂及治理抗药性害虫的理想药剂。为了明确茚虫威对草地贪夜蛾的生物活性及对其主要解毒酶活性的影响,为使用茚虫威科学防治草地贪夜蛾提供参考,本研究采用浸叶法测定了广西南宁草地贪夜蛾种群3龄幼虫对茚虫威敏感性及增效醚(PBO)、磷酸三苯酯(TPP)、顺丁烯二酸二乙酯(DEM)对茚虫威的增效作用;并测定了亚致死浓度(LC_(20))茚虫威对草地贪夜蛾体内MFO、GSTs和CarE酶的诱导作用。结果表明,茚虫威对草地贪夜蛾的LC_(20)、LC_(50)和LC_(90)分别为8.95、20.62 mg/L和73.57 mg/L。DEM、PBO和TPP对茚虫威的增效倍数依次为2.24、2.05和0.50倍。亚致死浓度(LC_(20))茚虫威处理后对3龄幼虫体内GSTs的活性和MFO含量与无药剂处理(CK)相比显著升高(P0.05),而CarE活性无显著变化(P0.05)。本文结果显示,广西草地贪夜蛾仍可以用推荐剂量80 mg/L茚虫威防治,而代谢抑制剂PBO和DEM对茚虫威有明显的增效作用,且GSTs活性和MFO含量在茚虫威诱导后显著升高,初步推测这两种解毒酶可能影响将来草地贪夜蛾对茚虫威的抗药性发展。     

虫螨腈胁迫对甜菜夜蛾保护酶系和解毒酶系的诱导效应

为探明虫螨腈对甜菜夜蛾幼虫体内生化代谢的影响及酶抑制剂对虫螨腈的增效潜力,采用点滴法测定了虫螨腈对甜菜夜蛾3、4、5龄幼虫的毒力和顺丁烯二酸二乙酯(DEM)、增效醚(PBO)、磷酸三苯酯(TPP)对虫螨腈的增效作用,并采用生化分析法测定了LD₂₅和LD₅₀剂量虫螨腈对甜菜夜蛾体内保护酶系和解毒酶系的影响。结果表明,虫螨腈对甜菜夜蛾不同龄期幼虫的毒力差异不大,处理后24h和48h的LD₅₀基本相同。PBO对虫螨腈有拮抗作用,增效比为0.21,而DEM和TPP对虫螨腈无增效作用。虫螨腈对甜菜夜蛾幼虫体内超氧化物歧化酶具有激活作用,对过氧化氢酶、过氧化物歧化酶及羧酸酯酶具有先抑制后诱导的作用;虫螨腈处理后6~24h,谷胱甘肽-S-转移酶活性显著提高,最高为对照的1.85倍;处理6h后,甜菜夜蛾体内细胞色素P450含量明显下降,而12~24h后,又明显上升,最高时为对照的1.86倍。     

甲氨基阿维菌素苯甲酸盐亚致死剂量对不同敏感性棉铃虫解毒酶活性的影响

室内用甲维盐对棉铃虫选育20代,获得敏感性降低2.32倍的汰选种群(RP20)。分别采用甲维盐对同源对照种群(CP)和RP20的亚致死浓度LC25对应处理两种群的3龄初幼虫48 h,测定试虫在3~6龄不同龄期内羧酸酯酶(CarE)和谷胱甘肽S 转移酶(GST)活性,分析酶活性变化动态。结果表明,(1)两种群(CP和RP20)均随龄期的增长,CarE比活力显著增大,而GST比活力先降低后趋于稳定。(2)CK处理下,RP20与CP相比,CarE比活力在3~6龄均增大且4~6龄差异显著,而GST比活力变化较小,仅3龄和6龄显著增大。(3)与CK处理相比,甲维盐LC25处理,两种群各龄期CarE比活力均增大,且CP试虫在4龄、6龄GST比活力显著增大,在3龄、5龄无显著差异,而RP20的3龄幼虫体内GST比活力被显著抑制,在4~6龄GST比活力无明显变化。初步判断,棉铃虫对甲维盐敏感性降低与CarE比活力增大有关;甲维盐亚致死剂量对棉铃虫CarE活性具有一定的诱导作用。     

Spectral and inhibitory interactions of methylenedioxyphenyl compounds with southern armyworm (Spodoptera eridania) midgut microsomes

Characteristics of the Type III optical difference spectra of 13 methylenedioxyphenyl compounds in NADPH-fortified armyworm midgut microsomes varied with the nature of the substituents in the aromatic ring. Compounds with electron-donating substituents yielded spectra with large $\text{427}\text{458}\text{nm}$ peak ratios, whereas those with electron-withdrawing groups exhibited low $\text{427}\text{458}\text{nm}$ peak ratios. Small amounts of carbon monoxide were generated during incubation of the 4,5-dihalo derivatives with midgut microsomes, and cis- and trans-methylenedioxycyclohexanes exhibited spectra with a major Soret peak at about 430 nm and a very weak absorbance maximum at about 480 nm. Formation of the Type III spectral complex occurred very rapidly and was associated with a marked decrease (up to 72%) in cytochrome P-450 levels as measured by carbon monoxide binding. Although a 24% reduction of cytochrome P-450 was observed in the absence of any measureable 458-nm spectral complex a linear relationship existed between further decreases in the cytochrome and the increase in Type III complex formation (458 nm). Inhibitory potencies of the compounds towards aldrin epoxidase and benzopyrene hydroxylase activities were not clearly correlated with either spectral complex formation or decrease in cytochrome P-450 and it is apparent that different factors are involved in the inhibition of different monooxygenase reactions.     

Effects of carbaryl and azinphos methyl on juvenile rainbow trout (Oncorhynchus mykiss) detoxifying enzymes

In this study, the effects of sublethal exposures to the anticholinesterase insecticides azinphos methyl (AzMe) and carbaryl on the detoxifying responses of juvenile rainbow trout Oncorhynchus mykiss were investigated. Juvenile specimen were exposed to sublethal concentrations of AzMe (2.5 and 5 μg/L) and carbaryl (1 and 3 mg/L) for 24, 48 and 96 h. Carboxylesterase (CbE), catalase (CAT) and glutathione S-transferase (GST) activities as well as reduced glutathione (GSH) and cytochrome P450-1A (CYP1A) levels were monitored in liver and/or kidney. In all exposed groups liver CbE was significantly inhibited. Liver and kidney GSH level was reduced after sublethal exposure to both compounds. Carbaryl induced CAT activity during the first 48 h of exposure, followed by a significant decrease, whereas AzMe continuously decreased CAT activity. GST activity and CYP1A were transiently induced at 24 h by carbaryl exposure (3 mg/L) but sublethal exposure to AzMe did not affect GST activity or CYP1A. Our results show that the O. mykiss detoxifying system are a target for carbaryl and AzMe action, probably affecting redox balance. Although the responses showed similar trends in both organs, they were more important in liver than in kidney. The early inhibitory effect in CAT activity and GSH content produced by AzMe may be associated with a high degree of oxidative stress. Early induction of CYP1A, GST and CAT by carbaryl followed by enzyme inhibition suggests a milder or delayed oxidative stress, revealing differences between both pesticides metabolization. CbE inhibition is a good biomarker for AzMe and carbaryl exposure.     

虱螨脲亚致死浓度对小菜蛾保护酶系和解毒酶系活力的影响

为阐明虱螨脲对小菜蛾亚致死效应的生化机制,采用室内生物测定法测定了LC_(10)和LC_(25)亚致死浓度处理小菜蛾3龄幼虫1、6、12、24、48和72 h后其体内保护酶系和解毒酶系的活力变化。结果表明:虱螨脲LC_(10)处理对小菜蛾幼虫体内超氧化物歧化酶(SOD)活力表现为早期诱导、后期抑制的作用,而对过氧化物酶(POD)则表现为先抑制后诱导的作用,对过氧化氢酶(CAT)仅在72h时具有诱导作用;LC_(25)处理对SOD表现为诱导-抑制-诱导-抑制的作用,对POD具有抑制作用,而对CAT具有诱导作用。经虱螨脲亚致死浓度处理后,小菜蛾幼虫体内酯酶和多功能氧化酶活力被明显抑制,且基本表现为浓度越高抑制作用越强;而谷胱甘肽S-转移酶(GST)活力仅在处理后1 h被诱导,之后被显著抑制。表明虱螨脲进入小菜蛾幼虫体内后,初期可诱导SOD、CAT和GST活力升高,以适应外界毒害的影响;但随着时间的延长,3种解毒酶活力被抑制,使其难以代谢,从而增强了对小菜蛾的毒性。     

辽阳地区稻水象甲对六种杀虫剂的敏感性及解毒酶活性测定

分别于2010和2011年采用点滴法测定了辽宁省辽阳地区张台子、柳壕和大石桥3个稻水象甲Lissorhoptrus oryzophilus Kuschel田间种群对吡虫啉等6种杀虫剂的敏感性。发现不同种群对同一药剂的敏感性相差可达4.2~49.4倍;2011年大石桥种群对阿维菌素等3种药剂的敏感性较2010年有所下降。通过室内毒力测定筛选出了5种可有效防治稻水象甲的药剂组合:阿维菌素和三唑磷、氯虫苯甲酰胺和三唑磷分别按质量比1∶1和1∶3组合,多杀菌素和辛硫磷按质量比1∶3组合。比较了3个种群稻水象甲成虫羧酸酯酶(CarE)、乙酰胆碱酯酶(AChE)和谷胱甘肽S-转移酶(GSTs)的活性,初步探讨了其敏感性不同的可能机制。研究结果可为该地区稻水象甲的有效控制提供参考。     

Effect of host plants on fitness traits and detoxifying enzymes activity of Helopeltis theivora, a major sucking insect pest of tea

Helopeltis theivora Waterhouse (Heteroptera: Miridae) is a major sucking insect pest of tea (Camellia sinensis) which feeds on a wide variety of alternative host plants. Feeding biology and fitness traits of H. theivora, on two alternative host plants, viz., Mikania micrantha (Asteraceae) and Psidium guajava (Myrtaceae), besides C. sinensis (Theaceae), were studied along with corresponding levels of xenobiotic defense enzymes. C. sinensis is the preferred host of H. theivora. The development time of H. theivora is significantly shorter on C. sinensis (13.3?±?0.16?days) than on the two other hosts, M. micrantha (14.2?±?0.22?days) and P. guajava (14.7?±?0.23?days). Similarly, the fecundity (C. sinensis: 172.6?±?4.5 eggs/female, M. micrantha: 128.6?±?4.4 eggs/female, P. guajava: 118.7?±?3.3 eggs/female), oviposition period (C. sinensis: 24.1?±?0.7?days, M. micrantha: 22.5?±?0.6?days, P. guajava: 21.7?±?0.8?days) and hatchability (C. sinensis: 80.9?±?1.9%, M. micrantha: 69.4?±?1.6%, P. guajava: 64.1?±?1.7%) are recorded to be significantly higher on C. sinensis. The age at reproductive maturity and egg incubation periods were lower on C. sinensis than on the two other host plants. Host-based variation in H. theivora fitness traits is interpreted in light of differential activity of three principal xenobiotic detoxifying enzymes, the general esterases (GEs), glutathione S-transferases (GSTs) and cytochrome P450 monooxygenases (CYPs). The activities of these enzymes in H. theivora were significantly enhanced when the insect fed on M. micrantha and P. guajava as compared with on C. sinensis.     

四种植物源化合物对亚洲小车蝗存活率、解毒酶和保护酶活性的影响

为开发防控亚洲小车蝗Oedaleus asiaticus的生物农药,本研究于室内测定芦丁、单宁酸、烟碱和苦参碱4种植物源化合物处理后亚洲小车蝗3龄蝗蝻的存活率以及体内活性氧簇(reactive oxygen species,ROS)浓度、3种解毒酶和3种保护酶的活性.结果 显示:芦丁、单宁酸、烟碱和苦参碱处理后,亚洲小...     

The in vivo effect of mirex on soluble hepatic enzymes in the rat

Adult male and female rats fed dietary mirex in concentrations of 10, 20, 30, 40, and 50 ppm for 4 weeks exhibited significant decreases in liver levels of lactic dehydrogenase, malic dehydrogenase, sorbitol dehydrogenase, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase as compared to control levels. Enzyme losses were cytoplasmic and decreased in magnitude with increased time of exposure and dietary mirex concentrations. Serum sorbitol dehydrogenase levels were increased above control levels during the first week of mirex exposure while hepatic sorbitol dehydrogenase levels were concomitantly decreased below the control levels. Hepatic glutamic oxaloacetic transaminase levels were significantly decreased during the first week for all dietary mirex concentrations as were the other enzymes at the 40 and 50 ppm mirex concentrations. The magnitude of the enzyme decreases in female rat tissue was consistently lower than enzyme decreases in the male rat tissue fed equivalent dietary mirex dosages. Liver weights for male rats increased significantly at all dietary mirex levels during week one. However, only animals receiving the 40 and 50 ppm dietary mirex levels showed significant liver weight increases at the end of week 4. Female rat liver weights were increased at the 30 and 40 ppm mirex dietary levels after 4 weeks. No significant differences in body weights were observed for any dietary level of mirex. Mirex hepatic residues appeared to be equal for both sexes. No gross histological alterations were observed following treatment.