有机氯杀虫剂药理学.ppt
- 文档编号:2008357
- 上传时间:2022-10-26
- 格式:PPT
- 页数:26
- 大小:123.50KB
有机氯杀虫剂药理学.ppt
《有机氯杀虫剂药理学.ppt》由会员分享,可在线阅读,更多相关《有机氯杀虫剂药理学.ppt(26页珍藏版)》请在冰豆网上搜索。
第五章第五章有机氯杀虫剂药理学有机氯杀虫剂药理学lAlthoughtheorganochlorineinsecticideswerewidelyusedinagricultureandmalarialcontrolprogramsfromthe1940sto1960swithdramaticbenefits,theyfellintodisfavourbecauseoftheirpersistenceintheenvironment,wildlife,andhumans.1organochlorineinsecticideslTherelativelylowcostoftheseinsecticidesandunavailabilityofcompletesubstitutes(particularlyforDDT),however,ensuretheircontinueduseinafewcountries,butitseemslikelythatthiswillstilldecline.2organochlorineinsecticideslTheuseofDDTisstillacontroversialtopicandsometimes,politicalcorrectnessmayhavecontributedtolackofmalarialcontrolduetorestrictionofitsuse.3organochlorineinsecticideslIn2001theUnitedNationsDevelopmentProgrammeagreedthatDDTcouldbeusedincertaincircumstancestoprotectagainstmalariawhereresistancetoothervectorcontrolshaddevelopedespeciallyinthelightofitscontinuedeffectiveness.4organochlorineinsecticideslSymptomslIngeneral,thesignsofpoisoningproducedbydifferentorganochlorineinsecticidesaresimilar,thatisexpressionsofneuronalhyperactivity.5organochlorineinsecticideslRoutesofabsorptionlAllorganochlorineinsecticidescanbeabsorbedthroughtheskinaswellasbyrespiratoryandoralroutes,buttheimportanceofdermalabsorptionvariesgreatlyforthedifferentcompounds.6organochlorineinsecticideslDistribution,metabolismandexcretionlOrganochlorineinsecticideshavebecomeinfamousbecauseoftheirtendencytoaccumulateinhumans,animals,birds,andthegeneralenvironment.7organochlorineinsecticideslAftersingleorrepeateddoses,mostofthesechemicalseventuallyreachtheirhighestconcentrationsinadiposetissue.lChlorinatedhydrocarboninsecticidescanbemetabolizedbymicrosomalP-450systemtohydroxylderivatives.8organochlorineinsecticideslParentinsecticidesusuallyareexcretedeitherinthebile,orpossiblythroughtheintestinalwall,forfaecalexcretion.lMetabolitesareexcretedintheurineiftheyareofrelativelyhighpolaritysuchasglucuronides(葡(萄)糖苷酸).9organochlorineinsecticideslEffectsontheliverlDDTandotherorganochlorineinsecticidescausemarkedchangesintheliversofvariousrodents,andinsomespecies,especiallythemouse,thesechangesprogresstotumours.10organochlorineinsecticideslReproductiveinfluencelManyofthechlorinatedinsecticideshaveendocrinedisruptingproperties,perhapsbyactingasweakoestrogens.lSomestudieshaveimplicatedachronicoxidativestressinmechanismsofteratologicalactionoforganochlorinepesticides.11Lindanel1,2,3,4,5,6-Hexachlorocyclohexane(HCH)haseightseparablestericisomers.lLindane:
GammaHCHl-isomer,lindane:
accountedfortheinsecticidalproperties.12LindanelNeurotoxicityandbehaviorlThedifferentisomersofHCHhaveoppositepharmacologicalactions.Lindaneisastimulantofthenervoussystem,causingviolentepileptiform(癫痫样的)convulsionsthatarerapidinonsetandgenerallyfollowedbydeathorrecoverywithin24h.13LindanelLindanebindsspecificallytotheGABA-receptor-ionophorecomplex.14LindanelMutationandcarcinogenesislInhost-mediatedtestinmiceandindirecttestsonindicatororganisms,HCHwasnotmutagenic.Otherinvitrotestshaveshownlittleevidenceofgenotoxicormutagenicactivityoflindaneeither.15LindanelEffectsonreproductionlChronicadministrationoflindaneaffectsbreedingparametersinrats.16CyclodieneinsecticidelThecyclodieneandrelatedinsecticidesarealdrin,diedrin,endosulfanlendosulfanlAcuteoraltoxicity:
moderatetoxiclDecomposedeasilylSlightactivityinmutationalorchromosomalaberrationassay.17DDTlSynthesizedin1874lInsecticidalpropertiesdiscoveredin1939lUsedintheSecondWorldWarforcontrollingtyphusandmalariabothinpopulationsandtroops.lTheimportanceofDDTtothewareffortafter1943wasasimportantaspenicillin.18DDTlTheuseofDDTwasamajorreasonfortheeradicationofmalariaintheUnitedStatesandmanypartofEurope.lIthasbeenestimatedthatthenumberoflivessavedbyDDTrunsintomillions.19DDTlAbsorptionanddistributionlDDTisstoredinalltissuesandparticularlyhighconcentrationsarefoundinfat.20DDTlNeurotoxicitylThemajoreffectofDDTclearlyisonthenervoussystem,andthisseemstooccurbyslowingdowntheclosingof“gate”inaxonionchannels.lDDTisknowntoprolongopeningoftheiongatesofthesodiumchannel,perhapsbyaffectingphosphorylationofthe-sunbunit.21DDTlAnothereffectofDDTappearstobeonaxonalmembranesandinhibitionofNa+,K+,Mg2+ATPasesandCa2+-ATPaseregulatingcalciumlevelsattheaxonsurface.22DDTlMutationandCarcinogenesislIninvivostudieshighlevelsofDDThavebeenshowntoinducelivertumoursinratsandmice.lDDTpromotescarcinogenesisinitiatedbyaflatoxin(黄曲霉毒素)andotherchemicals.23DDTlChronicexposureandresponselThesafetyrecordforhumansintheuseofDD
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 有机 杀虫剂 药理学