TurkJZool 26(2002)97-100 ©TÜB‹TAK ResearchArticle LevelofLactateDehydrogenase(LDH)inResistantandSusceptible StrainsofCulicineMosquitoesoftheKarachiRegionafter TreatmentwithDDT,MalathionandCyfluthrin M.ArshadAZMI,ImtiazAHMAD,S.N.H.NAQVIandKahkashanAKHTAR ToxicologyLaboratory,DepartmentofZoology,UniversityofKarachi,Karchi-75270,PAKISTAN Received:10.11.2000 Abstract: TheeffectsofMalathion,Cyfluthrin,andDDTwereobservedontheactivityoflactatedehydrogenase(LDH)insusceptible andresistantstrainsofculicinemosquitoes. Biochemicalestimation(colorimetry)revealedaremarkableincreaseintheenzymeactivityinCulexfatigans (L.Y.strain).Incontrast, inCulexfatigans (G.I.strain)andCulexfatigans (K.Ustrain),inhibitionofenzymeactivitywasfoundaftertreatmentwithpesticides. KeyWords: Malathion,Cyfluthrin,DDT,LDH,Mosquitolarvae DDT,MalathionileCyfluthrinUygulamas›ndanSonraDayan›kl›veDayan›ks›z Culex Sivrisinek Soylar›ndaLactateDehydrogenase(LDH)Düzeyleri Özet: Malathion,CyfluthrinileDDT’nin,gerekdirençligerekseduyarl› Culex sivrisineksoylar›ndakilaktatdehidrogenaz(LDH) aktivitesiüzerineetkilerigözlenmifltir. Biyokimyasalhesaplamada(kolorimetri) Culexfatigans’ta(L.Y.soyu)enzimaktivitesindekaydade¤erbirartmagözlenmemifltir. Bunakarfl›nCulexfatigans G.I.ileCulexfatigans K.U.soylar›ndaböcekzehiriuygulamas›ndansonraenzimaktivitesininengellendi¤i görülmüfltür. AnahtarSözcükler: Malathion,Cyfluthrin,DDT,LDH,Sivrisineklarvas› Introduction havebeenconducted.Tofillthisgapthepresentstudies Mosquitoeshaveagreatimpactonhumanwelfare wereundertakenwiththreeinsecticides(DDT becausethefemalesofapproximately300speciesof (organochlorine),Cyfluthrin(Pyrethroid),andMalathion mosquitoesarebloodsucking,manyofwhichbiteman (Organophosphate))usedagainst Culexfatigans to andserveasvectorsofseveralsignificanthuman determinethelevelofresistancebydeterminingthe diseases.Mosquitoesaremoreharmful,infact,thanall enzymelevelthroughthecolorimetricmethod. speciesofratsandlicecombinedandtheircomplete controlisyetnotinsight.Investigationsondifferent MaterialsandMethods aspectsoforganochlorine,organophosphateand pyrethroidshavebeencarriedoutbyvariousworkers. Fortherearingofallstrains,thetechniqueofAshrafi Mostofthesestudiesdealwithsclerotization,fecundity, etal.(19)wasfollowedandintheexperimintsonlylate rd toxicity,morphologicalabnormalitiesandenzymelevels 3 instarlarvaewereused.Thethreestrainsof C. (1-9).Onenzymeestimationintheresistant,treatedand fatigans rearedweretheK.U.strain,collectedform non-treatedinsects,verylittleworkhasbeencarriedout campus,theL.Y.strain,collectedfromLyari,andtheG.I. (10-13).InPakistan,only,afewinvestigationshavebeen strain,collectedfromGulshan-e-IqbalinKarachi.The reportedonresistanceinmosquitoes(14-18),andno rearingwascariedoutattheinsectoryoftheDepartment systematicstudiesonthedeterminationofthelevelof ofZoology,UniversityofKarachi.Duringrearingperiod resistanceintheculicinemosquitopopulationinKarachi therelativehumidityandthetemperaturewere 97 LevelofLactateDehydrogenase(LDH)inResistantandSusceptibleStrainsofCulicine MosquitoesoftheKarachiRegionafterTre atmentwithDDT, MalathionandCyfluthrin maintainedat65±5%and28±3Crespcetively.The Results rd late3 instarlarvaeofeachstrainweretreatedwith Biochemicalestimation(colorimetry)afteroneminute LC50concentrationsofinsecticidefollowingtheWHO incubationrevealedthatMalathiondecreasedLDH standardmethod.After24h,larvaewere activity30%intheK.U.strainand58.33%intheG.I. homogenized.Thehomogenateswerecentrifiugedat strain,andincreasedactivity22.22%intheL.Y.Strain 1500rpmandthensupernatantswereseparatedand (Tables1-3);Cyfluthrindecreasedactivity33.33%inthe subjectedtobiochemical(colorimetry)tests.Forthe K.U.strainand50%intheG.I.strain,andincreased determinationoflactatedehydrogenase(LDH)activity, activity7.20%intheL.Y.strain(Tables4-6);andDDT BoehringerMannheimGmbhdignosticKitno.124885 decreasedactivity50%intheK.U.strainand66.66%in wasused,Readingsweretakenafterexactly1minute theG.I.strain,andincreasedactivity41.66%intheL.Y. at340nm. strain(Tables7-9). Table1. EffectofMalathiontreatment Compound Meanofenzymeunit S.D. S.E. 95% % (0.225ppmfor24h)onLDH (U/L) Confidencelimit Inhibition activityinthelarvaeoftheK.U. strain.Intervaltime(A)......1min. Control 30 14.2 8.25 14.15-46.5 0.0 Malathion 21 13.74 7.93 5.44-36.55 30.0 Table2. EffectofMalathiontreatment(0.44 Compound Meanofenzymeunit S.D. S.E. 95% % ppmfor24h)onLDHactivityin (U/L) Confidencelimit Inhibition thelarvaeoftheG.I.strain.Interval time(A)......1min. Control 36 24.37 14.0 9.07-64.25 0.0 Malathion 15 5.19 3.0 9.12-20.88 58.33 Table3. EffectofMalathiontreatment(0.5 Compound Meanofenzymeunit S.D. S.E. 95% % ppmfor24h)onLDHactivityin (U/L) Confidencelimit Inhibition thelarvaeoftheL.Y.strain.Interval time(A)......1min. Control 21 13.74 7.93 5.44-36.55 0.0 Malathion 27 9.0 5.19 16.81-37.18 22.22 Table4. EffectofCyfluthrintreatment Compound Meanofenzymeunit S.D. S.E. 95% % (0.000165ppmfor24h)onLDH (U/L) Confidencelimit Inhibition activityinthelarvaeoftheK.U. strain.Intervaltime(A)......1min. Control 36 5.19 3.0 18.12-29.88 0.0 Cyfluthrin 24 18.5 10.68 15.39-57.27 33.33 Table5. EffectofCyfluthrintreatment Compound Meanofenzymeunit S.D. S.E. 95% % (0.00018ppmfor24h)onLDH (U/L) Confidencelimit Inhibition activityinthelarvaeoftheG.I. strain.Intervaltime(A)......1min. Control 42 14.29 8.25 26.49-58.84 0.0 Cyfluthrin 21 10.30 6.0 9.24-32.76 50.0 Table6. EffectofCyfluthrintreatment Compound Meanofenzymeunit S.D. S.E. 95% % (0.00045ppmfor24h)onLDH (U/L) Confidencelimit Inhibition activityinthelarvaeoftheL.Y. strain.Intervaltime(A)......1min. Control 38 19.21 11.09 16.91-60.41 0.0 Cyfluthrin 41 25.40 14.66 12.92-70.41 7.20 98 M.A.AZMI,I.AHMAD,S.N.H.NAQVI,K.AKHTAR Table7. EffectofDDTtreatment(0.175 Compound Meanofenzymeunit S.D. S.E. 95% % ppmfor24h)onLDHactivityin (U/L) Confidencelimit Inhibition thelarvaeoftheK.U.strain. Intervaltime(A)......1min. Control 30 21.36 12.33 6.16-54.5 0.0 DDT 15 5.19 3.0 9.12-20.88 50.0 Table8. EffectofDDTtreatment(0.325 Compound Meanofenzymeunit S.D. S.E. 95% % ppmfor24h)onLDHactivityin (U/L) Confidencelimit Inhibition thelarvaeoftheG.I.strain.Interval time(A)......1min. Control 36 18.5 10.68 15.39-57.27 0.0 DDT 12 5.19 3.0 6.12-17.88 66.66 Table9. EffectofDDTtreatment(0.425 Compound Meanofenzymeunit S.D. S.E. 95% % ppmfor24h)onLDHactivityin (U/L) Confidencelimit Inhibition thelarvaeoftheL.Y.strain.Interval time(A)......1min. Control 21 7.93 13.74 5.44-36.55 0.0 DDT 36 18.5 10.68 15.39-57.27 41.55 Discussion hadtoxiceffects.ChangeandJordan(25)reported Insecticidesgenerallyaffecttheenzymaticactivitiesof reducedesteraseactivitybysyntheticpyrethroid insects.Inthepresentinvestigationtheeffectsof treatment.Azmietal.(17-18)reportedtheactivityof organochlorine(DDT),organophosphate(Malathion)and Phosphomonoesterasesinsusceptibleandresistant pyrethroids(Cyfluthrin)wereobservedonthelactate strainsof C.fatigans .SaleemandShakoori(26), dehydrogenase(LDH)activityinthelarvaeofC.fatigans. reportingresistancein Triboliumcastaneum (Pakstrain) Someworkersinthepastalsostudiedtheseeffects;for againstMalathion,reportedtheabsenceofcross instance,Ashrafietal.(20)foundthattheacetone resistanceinthisstrainagainstpermethrinand (check)inhibitstheactivityofphosphataseabout30% cypermethrin.IntheCTC-12straintheyfoundresistance andthisinhibitonwasrestoredinMalathion,Parathion againstPyethroid.Theyreportedincreased andPetkolin(OC)(inacetonesolvent)treatedinsects. carboxylesterase,cholinesterase,protease,andlactate ThisconfirmstheLDHinhibitonbyDDTandMalathionin dehydrogenaseactivities,butreducedacidphosphatase thepresentsuspecptiblestrain.InthecaseoftheL.Y. activity.InthepresentfindingsLDHactivitywashigherin strain,whichisresistanttosomeextent,thereisan thetreaatedinsectsthaninthoseinthecontrolbatch. increaseinLDHactivity. Thusthepresentfindingsconfirmtheirresults.The differencesmaybedueeithertostraindifferenceorto HayaokaandDauterman(21)reportedthat someunknownfactors. chlorinatedhydrocarbonsweremoreeffectiveinducersof glutathioneS-tansferaseactivitythantheotherpesticides Formtheabovediscussion,itisprobablethatthe evaluated.Likewise,VermaandRahman(22)reported levelsofsomeenzymesincreaseinresistantstrains,as theeffectofcertaininsecticidesontransaminasesin C. reportedbyanumberoftheabovewerkers.Itishoped fatigans whereasMeanyandPocker(23)observed thatthepresentstudywillcontributetoabetter inactivationofLDHbyorganochlorine.Scottand understandingoftheresistanceofmosquitoesofKarachi Matsumura(24)reportedthatcypermethrinand regionandwouldhelppreventindiscriminateuseofsuch deltamethrindidnotcauseapparentnerveexcitationbut pesticides. 99 LevelofLactateDehydrogenase(LDH)inResistantandSusceptibleStrainsofCulicine MosquitoesoftheKarachiRegionafterTre atmentwithDDT, MalathionandCyfluthrin References 1. 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