欢迎来到天天文库
浏览记录
ID:62093857
大小:547.50 KB
页数:31页
时间:2021-04-15
《最新乙酰胆碱受体杀虫剂药理学教学讲义ppt.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、乙酰胆碱受体杀虫剂药理学1.nerveimpulsearrives2.voltage-gatedCa2+channelsopen3.Synapticvesiclesfusewithplasmamembraneanddumpcontents4.SignallingmoleculecausesresponseinpostsynapticmembraneSequenceofevents2二、氯化烟酰、沙蚕毒素类杀虫剂3Nicotine,intheformoftobaccoextract,hasbeenusedasaninsecticidesincethemid-eighteen
2、thcenturyandstillranksasanexcellentcontactinsecticide.PlantinsecticideBotanicalinsecticide1Nicotine7Nicotineattacksacetylcholinereceptors,whichresemblecholinesterases.Nicotineselectivelyattackstheneuromuscularjunctionofmammalsandthesynapticganglionofinsectswithoutseverelyattackingotherkno
3、wnacetylcholinereceptors.1Nicotine8Nicotine↓AChR(acetylcholinereceptor)↓SodiumChannelOpen↓SodiumInflux↓NerveImpulse1Nicotine9Themostconspicuousfeatureofnicotinepoisoningininsectsisitsselectiveinhibitoryactionsonnervegangliaandsynapses.Itappearsthatnicotineisveryselectiveinchoosingthebindi
4、ngsitesinbothinsectsandmammals.1Nicotine10Nicotineselectivelyattackstheneuromuscularjunctionofmammalsandthesynapticgangliaofinsectswithoutseverelyattackingotherknownacetylcholinereceptorsortheacetylcholinesterase,whichisknowntobesimilarinproteinstructuretotheacetylcholinereceptors.1Nicoti
5、ne11Nicotinecanmimictheactionofacetylcholineinvivoundertheproperconditions.Itislikelythatthereceptorssusceptibletonicotinecannotdistinguishbetweenacetylcholineandnicotine.1Nicotine12本剂为植物源杀虫剂,其有效杀虫成分为由烟草中提取的烟碱。纯品为无色油状液体,性质不稳定。易挥发,能溶于水和有机溶剂。遇光和空气易变成褐色,有奇臭味和强烈刺激性。对害虫有胃毒、触杀和熏蒸作用,还有杀卵作用。烟碱易挥发
6、,故残效期较短,而它的盐类(如硫酸烟碱)则较稳定,残效期长。1Nicotine132Imidacloprid(吡虫啉)Chloronicotinylinsecticide(氯化烟酰类杀虫剂)Becauseofhighmammaliantoxicityandrelativelylowinsecticidalactivitynicotineitselfhasnotbeenwidelyusedasapesticidesincethe1940s.142Imidacloprid(吡虫啉)Beginningwithnithiazinein1979somerelatedsyntheti
7、csubstancereactingatthesamereceptorasnicotinewerediscovered.Imidaclopridwasintroducedin1992asanewneonicotinoidinsecticides.152Imidacloprid(吡虫啉)Imidaclopridhassimilaritiestonicotineandacomparablemodeofaction.Itisactiveagainstsuckinginsectsbecauseoftheuniqueplant-syst
此文档下载收益归作者所有