Joint action of phoxim and fenvalerate on reproduction in male rats

Aim: To evaluate the joint action of phoxim and fenvalerate on the reproductive function in male Sprague-Dawley rats. Methods: The 2×2 factorial analysis experiment was used in the study. The pesticides were orally given at daily doses of phoxim (Pho) 8.2 nig/kg, fenvalerate (Fen) 3.3 mg/kg and Pho 8.2+Fen 3,3 mg/kg (Pho:Fen = 5:2), 5 days a week for 60 days. Sperm motility was measured with computer-assisted sperm motility analysis (CASA) and daily sperm production estimated. Immunoenzymatic method and electron microscopy were used to evaluate the serum testosterone and the testicular morphology, respectively. Results: There were significant decreases in sperm motility parameters in the treated animals, including straight line velocity (VSL), beat cross frequency (BCF), linearity (LIN) and straightness (STR). After treated with Fen, significant decreases in VSL, LIN and STR were demonstrated. Significant decreases of daily sperm production were seen in animals treated with Pho and Pho+Fen in comparison with the controls. Serum testosterone levels were not significantly changed in the treated groups. Factorial ANOVA showed that no significant interactions were noted between Pho and Fen in sperm motility, sperm production and serum testosterone. Both the single and mixed pesticides caused various degrees of testicular lesions, involving vacuolation of endoplasmic reticulum and necrosis of Sertoli cells. Conclusion: The pesticides may cause sperm motility changes and testicular lesions in male rats. The action of Pho and Fen may be additive.

Fenvalerate-induced Alterations in Calcium Homeostasis in Rat Ovary

Objective To observe the effects of fenv＇,derate on calcium homeostasis in rat ovary. Methods Female SpragueDawley rats were orally given fenvalerate at dally doses of 0.00, 1.91, 9.55, and 31.80 mg/kg for four weeks. The ovary ultrastucture was observed by electron microscopy. Serum free calcium concentration was measured by atomic absorption spectrophotometry. The activities of phosphorylase a in rat ovary were evaluated by the chromatometry. The total content of calmodulin in ovary was estimated by ELISA at each stage of estrous cycle. Radioimmunoassay （R/A） was used to evaluate the level of serum progesterone. Results Histopathologically, damages of ovarian corpus luteum cells were observed. An increase in serum fi＇ee calcium concentration was observed in rats treated with 31.80mg/kg fenvalerate. The activities of phosphorylase a enhanced in all treated groups, and fenvalerate increased the total content of calmodulin significantly in estrus period. Serum progesterone levels declined in fenvalerate exposed rats in diestrus. Conclusion Fenvalerate interferes with calcium homeostasis in rat ovary. Also, the inhibitory effects of fenvalerate on serum progesterone levels may be mediated partly through calcium signals.

Sub-Lethal Effects of Fenvalerate on the Development, Fecundity, and Juvenile Hormone Esterase Activity of Diamondback Moth, Plutella xylostella (L.)

The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.

Relative Toxicity of Aldrin, Fenvalerate, Captan and Diazinon to the Freshwater Food-Fish, Clarias Batrachus

The median lethal concentrations (LC50s) of aldrin, fenvalerate, captan and diazinon were determined for Clarias batrachus by trimmed Spearman-Karber method. The potency ratios of toxicity among them were analysed by parallel-line bioassay with quantal responses. The LC50s for 40 day of exposure of aldrin, fenvalerate, captan and diazinon were 0.00036,0.0094, 0.5473 and 2.4186 ppm respectively. These values were lower than those obtained for an exposure of 96 hour. It shows the greater toxicity of the pesticides in a long-term exposure. The relative toxic potency of aldrin fenvalerate, captan and diazinon was in a ratio of 6807:241:4:1 respectively. Thus the chemically different groups of pesticides exhibit an order of toxicity as aldrin > fenvalerate >captan > diazinon for the freshwater catfish, Clarias batrachus. It infers that the catfish is most sensitive to aldrin and least sensitive to diazinon. The comparison of the sensitivity of various species tested against these pesticidal chemicals has also been done to review the available information.

Hepatotoxic Alterations Induced by Subchronic Exposure of Rats to Formulated Fenvalerate (20% EC) by Nose Only Inhalation

Objective Fenvalerate (20% EC) is a synthetic pyrethroid, which is commonly used in India by farmers for the protection of many food and vegetable crops against a wide variety of insects. However, its inhalation toxicity data is very limited in the literature due to the fact that the exposure levels associated with these effects were usually not reported. Hence, inhalation exposure was carried out to investigate the hepatotoxic effects. Method Adult male rats were exposed to fen for 4 h/day, 5 days a week for 90 days by using Flow Past Nose Only Inhalation Chamber. Sham treated control rats were exposed to compressed air in the inhalation chamber for the same period. Results The results indicated hepatomegaly, increased activities of serum clinical enzymes (indicative of liver damage/dysfunction) along with pronounced histopathological damage of liver. Conclusion The hepatotoxic potential of formulated Fen (20% EC) in rats exposed by nose only inhalation is being reported for the first time and warrant adequate safety measures for human beings exposed to this insecticide, particularly by inhalation route.

Cloning of Partial Sodium Channel Gene From Strains of Fenvalerate-Resistant and Susceptible Cotton Aphid(Aphis gossypii Glover)

The strain of fenvalerate-resistant cotton aphids was selected using fenvalerate insecticide in the laboratory, the resistance factor of the strain was 199.54. Three degenerate primers were designed and used to perform PCR amplification. A cDNA encoding partial sodium channel gene was cloned from the fenvalerate-resistant and -susceptible strains. There were two nucleotide acid differences between fenvalerate-resistant strain and -susceptible strain, resulting in an amino acid mutation, Met→Leu. It is predicted that the mutation is related to the cotton aphid resistance to fenvalerate.

亚致死剂量氰戊菊酯对家蚕生长发育的影响

采用浸叶法测定了氰戊菊酯对家蚕的急性毒性和生长发育毒性,为农桑混栽区害虫防治药剂选择提供参考。急性毒性试验结果表明:氰戊菊酯对2龄起蚕的96 h-LC50为0.251~0.570 mg·L^(-1),属于高毒和剧毒级别。生长发育毒性试验结果表明:亚致死剂量(0.062 8、0.020 9、0.006 98、0.002 33、0.000 775 mg·L^(-1))的氰戊菊酯处理对家蚕眠蚕体重和发育历期有一定的影响,但随着家蚕龄期的增长其影响逐渐减弱;0.002 33、0.000 775 mg·L^(-1)氰戊菊酯处理对家蚕化蛹率和死笼率有显著影响(P<0.05),对个体生长发育影响明显;0.062 8、0.020 9、0.006 98 mg·L^(-1)氰戊菊酯处理组家蚕茧层量显著低于对照组(P<0.05)。可见,氰戊菊酯对家蚕具有极高的急性毒性和慢性毒性效应。因此,在农桑混栽区使用氰戊菊酯时应注意,避免雾滴漂移或其他农事活动污染桑园引起家蚕中毒。

海洋生物体中氯氰菊酯、氰戊菊酯、溴氰菊酯残留测定的不确定度分析

根据计量的不确定度判断方法和表示理论,在标准溶液、试样称重、样品定容、标定曲线、仪器检测和试样测量六大领域,对气相色谱法检测的海洋生物体中溴氰菊酯、氰戊菊酯、次溴氰菊酯等有机物的不确定性分析与评价。结果表明,标准曲线所用溶液配制过程对测量结果的不确定度贡献较大,占总比重的28%。样品重复性测定和仪器重复性测量也引入了较多的不确定度,这为准确测量海洋生物体中的氯氰菊酯、氰戊菊酯和溴氰菊酯,减少测量不确定度,提升测量精度提供改进方向。

离子液体-分散液液微萃取结合高效液相色谱法快速分析茯苓中氰戊菊酯和联苯菊酯农药残留

离子液体-分散液液萃取法被成功地应用于萃取和富集中药材茯苓中氰戊菊酯和联苯菊酯。1-辛基-3-甲基咪唑六氟磷酸盐([C_8mim][PF_6])作为萃取溶剂,1-丁基-3-甲基咪唑四氟硼酸盐([C_4mim][BF_4])为分散剂。整个萃取过程不需要加入任何有机溶剂,萃取过程快速,3min内就可以达到萃取平衡。茯苓中目标化合物的加样回收率在95.7%~98.3%之间,检出限为0.50和0.40 ng·mL^(-1)之间,结果令人满意,说明该实验方法适用于检测中药材中氰戊菊酯和联苯菊酯农药残留。

氰戊菊酯对大鼠睾丸Leydig细胞睾酮合成的影响及其机制

目的探讨氰戊菊酯(Fen)对大鼠睾丸Leydig细胞睾酮合成的影响及其可能机制。方法采用差速贴壁法分离提纯SD大鼠睾丸Leydig细胞。用0、25、50和100μmol/L Fen处理Leydig细胞1、12和24 h,采用ELISA法检测睾酮水平。设置空白对照组(加入0.1%DMSO处理)、Fen暴露组(加入100μmol/L Fen处理)、Fen+NAC组(加入100μmol/L Fen和5 mmol/L NAC处理)、Fen+CsA组(加入100μmol/L Fen和2 mmol/L CsA处理),给药后继续培养24 h。采用流式细胞仪检测活性氧(ROS)和线粒体膜电位变化,ELISA法检测睾酮水平及谷胱甘肽(GSH)、cAMP含量,化学发光法检测ATP含量,Western blotting检测超氧化物歧化酶(SOD)、类固醇激素合成急性调节蛋白(StAR)、3β-羟类固醇脱氢酶(3β-HSD)和细胞色素P450胆固醇侧链裂解酶(CYP11A1)的表达。结果选择100μmol/L Fen处理24 h进行实验。与空白对照组比较,Fen暴露组Leydig细胞睾酮合成水平,GSH、SOD、ATP、cAMP含量,线粒体膜电位,以及StAR、3β-HSD、CYP11A1蛋白相对表达量明显降低(P<0.01),ROS含量明显升高(P<0.01);与Fen暴露组比较,Fen+NAC组、Fen+CsA组Leydig细胞睾酮合成水平,GSH、SOD、ATP、cAMP含量,线粒体膜电位,以及StAR、3β-HSD、CYP11A1蛋白相对表达量明显升高(P<0.05或P<0.01),ROS含量明显降低(P<0.01)。结论Fen可能通过诱导氧化应激引起大鼠睾丸Leydig细胞线粒体损伤,致使ATP和cAMP合成受阻,从而抑制依赖cAMP/PKA信号通路的睾酮合成相关蛋白和酶的表达,最终导致Leydig细胞睾酮合成障碍。

氰戊菊酯通过诱导mPTP开放干扰小鼠睾丸间质细胞睾酮合成的机制

目的探讨氰戊菊酯(Fen)干扰小鼠睾丸间质细胞(TM3细胞)睾酮合成的机制。方法TM3细胞随机分为对照组(Control group,0μmol/L Fen)、25μmol/L Fen暴露组、25μmol/L Fen+5 mmol/L NAC组、25μmol/L Fen+10μmol/L BAPTA-AM组;采用CCK-8法检测染不同浓度及不同作用时间的细胞增殖情况;ELISA法检测小鼠睾酮(T)和cAMP的含量;DCFH-DA荧光探针检测细胞内活性氧(ROS)含量;Fluo-4/AM探针检测细胞内Ca^(2+)浓度;JC-1荧光探针检测线粒体膜电位(MMP)变化情况;生化比色法测定细胞ATP含量;Western blot检测3β-HSD、StAR、ANT4和CyPD表达水平。结果Fen暴露后,TM3细胞ROS水平和胞内Ca^(2+)浓度上升(P<0.01),线粒体膜通透性转运孔(mPTP)组成成分ANT4和CyPD表达水平上升(P<0.01),MMP水平下降(P<0.01),细胞ATP和cAMP合成能力降低(P<0.01),cAMP/PKA信号通路依赖性的StAR蛋白和3β-HSD表达水平下降(P<0.01),睾酮合成能力随之下降(P<0.01);与25μmol/L Fen暴露组比较,25μmol/L Fen+5 mmol/L NAC组和25μmol/L Fen+10μmol/L BAPTA-AM组TM3细胞睾酮合成水平显著上升(P<0.05)。结论Fen暴露后,TM3细胞ROS和胞浆Ca^(2+)浓度上升,二者通过协同效应引起mPTP开放,细胞ATP和cAMP合成障碍,cAMP/PKA信号通路依赖性的睾酮合成蛋白和酶表达下降,TM3细胞睾酮合成受阻。本研究的结果提示抑制ROS和Ca^(2+)的信号作用可能有助于抑制Fen诱导的TM3细胞mPTP开放并改善Fen暴露所致TM 3细胞睾酮合成障碍。

氰戊菊酯过度激活Ca^(2+)/CaM/CaMKⅡ信号通路诱发线粒体损伤干扰TM3细胞睾酮合成

目的利用胞内Ca^(2+)螯合剂BAPTA-AM和CaM阻断剂TFP探讨Ca^(2+)/CaM/CaMKⅡ信号通路在氰戊菊酯(Fen)诱发小鼠睾丸间质细胞(TM3细胞)线粒体损伤和睾酮合成障碍中的作用。方法TM3细胞实验分为对照组、Fen暴露组(25μmol/L Fen)、Fen+BAPTA-AM组(25μmol/L Fen+5 mmol/L BAPTA-AM)、Fen+TFP组(25μmol/L Fen+10μmol/L TFP),Fen暴露时长为24 h。采用ELISA法检测TM3细胞的睾酮和环磷酸腺苷(cAMP)水平,化学比色法检测TM3细胞的ATP水平,Flou-4/AM探针测定细胞内Ca^(2+)水平,JC-1染色法测定TM3细胞的线粒体膜电位(MMP)改变,蛋白免疫印迹法检测CYP11A1、3β-HSD、StAR、CaM、p-CaMKⅡ、CaMKⅡ、Bax和Bcl-2的蛋白表达水平。结果Fen暴露组TM3细胞的T、ATP和cAMP含量下降,MMP水平降低,睾酮合成的相关蛋白和酶CYP11A1、3β-HSD、StAR表达减少(P<0.01);同时,TM3细胞胞内的Ca^(2+)水平显著上升(P<0.01),CaM、p-CaMKⅡ/CaMKⅡ、Bax蛋白表达升高(P<0.01),Bcl-2蛋白表达下降(P<0.01)。Fen+BAPTA-AM组和Fen+TFP组TM3细胞的睾酮、ATP和cAMP含量上升,MMP水平升高(P<0.01),睾酮合成相关的蛋白和酶CYP11A1、3β-HSD、StAR表达增加(P<0.01),CaM、p-CaMKⅡ/CaMKⅡ及Bax蛋白表达下降,Bcl-2蛋白表达增加(P<0.01)。结论Fen诱发的TM3细胞mPTP开放以及睾酮合成障碍可能与Fen暴露后TM3细胞胞内Ca^(2+)超载、CaM和p-CaMKⅡ表达上调引起的Ca^(2+)/CaM/CaMKⅡ信号通路过度激活有关。

杀灭菊酯的微生物降解及酶促降解

测定了降解菌ＹＦ１１及其胞内酶对杀灭菊酯的降解特性．在纯培养系统中，菌量为ＯＤ４１５ｎｍ０．２０时，ＹＦ１１对大于３０ｍｇ／Ｌ的杀灭菊酯的降解呈零级动力学特征，浓度为３０－１００ｍｇ／Ｌ时，降解速率为１．８７６—２．１２４ｍｇ／（Ｌｈ）；浓度大于２００ｍｇ／Ｌ的杀灭菊酯对降解菌ＹＦ１１的降解产生抑制作用．降解速率与菌量近似成正比关系；１０ｍｇ／Ｌ杀灭菊酯的降解曲线呈一级动力学特征．从ＹＦ１１提取的粗酶液在３２．５℃、ｐＨ８．０时对杀灭菊酯显示最大的降解活性，其最大降解速率为２１１．８ｎｍｏｌ／（ｍｉｎｍｇ蛋白）、米氏常数（Ｋｍ）为４１．

氰戊菊酯及代谢物对土壤过氧化氢酶活性的影响

通过试验研究了氰戊菊酯及其代谢产物对土壤过氧化氢酶活性的影响,结果表明,不同浓度的氰戊菊酯对土壤过氧化氢酶活性的影响也不同,浓度越高,对供试土壤过氧化氢酶活性的影响越强烈;在氰戊菊酯浓度为1,10,40,150g/g时,其影响过程为先抑制后激活再恢复,而在高浓度(150g/g)的氰戊菊酯作用下,激活作用最强;氰戊菊酯的代谢产物(水解和光解产物)对供试土壤过氧化氢酶活性的影响均略小于氰戊菊酯原药;随着光照时间的延长,氰戊菊酯光解产物对土壤过氧化氢酶活性的影响减弱,即对供试土壤生态环境影响减弱.

氰戊菊酯对雄性大鼠生殖内分泌系统的影响

目的 :研究氰戊菊酯 (Fen)对雄性生殖内分泌系统的损害作用及其机制。 方法 :将不同剂量的Fen(0、2 .4、12、6 0mg/kg) ,每日分别对雄性成年SD大鼠连续灌胃 ,染毒 15、30d ,应用RIA法测定大鼠血清中FSH、LH、T和睾丸匀浆中T的水平 ,同步测定睾丸标志酶ACP、γ GT的活性 ,并采用精子头计数法观测每日精子生成量 (Spr)的变化。 结果 :与对照组相比 ,染毒 15d时 ,血清中FSH水平在≤ 12mg/kg剂量组均明显升高 (P <0 .0 1) ,血清中LH含量在 12mg/kg剂量组显著增加 (P <0 .0 1) ,而睾丸匀浆中T在≥ 12mg/kg剂量组中表现为显著下降 (P<0 .0 1) ;染毒至 30d时 ,血清中FSH水平在≥ 12mg/kg剂量范围继续呈现显著增加 (P <0 .0 1) ,睾丸匀浆中T在2 .4mg/kg剂量组则降低 (P <0 .0 5 )。ACP活性在染毒 15d时 2 .4mg/kg剂量组表现为升高 (P <0 .0 5 ) ,继续染毒至 30d时 6 0mg/kg剂量组则显著减低 (P <0 .0 5 ) ;γ GT活性则始终随染毒剂量的增加而降低 (P <0 .0 5 )。Spr与染毒剂量有明显的剂量依赖关系 ,在≥ 12mg/kg剂量范围显著减少 (P <0 .0 1)。 结论 :Fen对雄性大鼠有明显的生殖毒性 ,可影响其血清及睾丸性激素水平和酶活性 。

毒死蜱、氰戊菊酯和高效氯氰菊酯在甘蓝中的残留动态研究

采用气相色谱法(GC-ECD)进行农药残留检测,研究了毒死蜱、氰戊菊酯和高效氯氰菊酯在春季结球甘蓝中的残留降解动态和最终残留量。结果表明,3种农药的半衰期不同,在甘蓝中不具有积累性残留效果。按照农药推荐使用量,毒死蜱、高效氯氰菊酯和氰戊菊酯的半衰期分别为2.1、3.7和2.8d。参照我国、日本和国际法典委员会(CAC)规定的残留限量要求,计算出3种农药的安全间隔期,建议高效氯氰菊酯的安全间隔期为3d,适合在甘蓝种植中使用;其他两种农药的安全间隔期范围在3～14d之间,应该执行良好农业操作,严格遵照农药标签说明使用。结论认为3种农药不同的最大残留限量(MRL)都在其理论MRL的范围内,都具有安全属性。

氰戊菊酯对原生动物群落的毒性

以PFU采集的原生动物群落为受试对象,研究了氰戊菊酯 48h的急性毒性,得出半数致死浓度LC50为 15. 83mgL-1, 安全浓度LC10为 2. 09mgL-1.加入氰戊菊酯后,原生动物的群落结构发生变化,各个功能类群均受到不同程度的损伤,一些食菌和碎屑者类原生动物对氰戊菊酯表现出较高的耐受性, 随着氰戊菊酯浓度的增加,其在群落中的优势度更加明显.氰戊菊酯的加入致使原生动物群落结构简单化,对生态系统的物质循环和能量流动产生较大影响.图 1表 1参

氰戊菊酯和锐劲特对原生动物群落的联合毒性试验研究

氰戊菊酯和锐劲特两种农药被广泛用于茶树、果树、水稻、蔬菜等的病虫害防治,它们同时出现在同一环境中的机会非常多,但有关两种农药对生态系统的复合毒性效应却未见有研究报道.与单种生物毒性试验相比,群落级生物毒性试验对毒物胁迫的反映更具环境真实性.以PFU在天然淡水中采集到的原生动物群落为靶生物,研究了氰戊菊酯和锐劲特2种农药对淡水原生动物群落的毒性效应,对于水生生态环境的保护有特殊的意义.研究结果表明,2种农药单独存在时对原生动物群落的48h半数致死浓度分别为15 93mg·L-1和35 83mg·L-1;2种物质以等毒性比(单一LC50的比值)混和,进行联合毒性试验研究,用Marking相加指数法进行评价,其AI值为0 9,表现为协同作用.氰戊菊酯和锐劲特进入水环境后,将使水环境中原生动物群落的结构和组成发生变化,原生动物种类数减少,群落结构变得简单.在所有种类中,纤毛虫受损最大,水生生态系统的物质循环和能量流动将会受到一定程度的影响.

氰戊菊酯与甲苯对小鼠脑细胞氧化性损伤作用的研究

单独用氰戊菊酯或甲苯染毒时小鼠脑组织中丙二醛和氧化型谷胱甘肽含量均显著增加。还原型谷胱甘肽含量和超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶的活性均有不同程度的下降。并呈一定的剂量－反应关系。说明氰戊菊酯和甲苯对小鼠脑细胞具有一定的氧化毒性。但当氰戊菊酯和甲苯以４：５混合染毒时，引起丙二醛、氧化型和还原型谷胱甘肽的含量、抗氧化性酶活性的变化反而减少。提示二者对小鼠脑细胞的氧化毒性具有一定的拮抗作用。

叶类蔬菜低农药残留基因型筛选研究

采用气相色谱法(GC-NPD,ECD)测定毒死蜱和氰戊菊酯残留量,研究了菠菜(Spinacia oleracea L.)和不结球白菜(Brassicaca mpestris L.ssp.Chinensis Makino var.communis Tsen et Lee)中毒死蜱、氰戊菊酯的残留动态。结果表明,菠菜中毒死蜱残留量、不结球白菜中毒死蜱和氰戊菊酯残留量存在着明显的基因型差异。同一不结球白菜基因型,毒死蜱和氰戊菊酯的残留量达到《GB2763-2005食品中农药最大残留限量》中规定的叶类蔬菜农药最大残留限量所需要的时间存在明显差异,且毒死蜱达到最大残留限量所需要的时间比氰戊菊酯长,因此在选择低农药残留基因型时,应首先考虑农药残留时间长、最大农药残留限量低的农药品种。菠菜品种sp0723、卡尔以及不结球白菜品种矮抗青、无锡605和青选3号属于低农药残留的基因型,在生产上推广应用有利于提高叶类蔬菜的食用安全水平。