Pesticide Mixtures Induce Immunotoxicity: Potentiation of Apoptosis and Oxidative Stress

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dc.contributor.authorRabideau, Christine L.en
dc.contributor.committeechairMisra, Hara P.en
dc.contributor.committeememberCrisman, Mark V.en
dc.contributor.committeememberGregory, Eugene M.en
dc.contributor.departmentBiomedical Sciences and Pathobiologyen
dc.date.accessioned2014-03-14T20:43:30Zen
dc.date.adate2001-08-16en
dc.date.available2014-03-14T20:43:30Zen
dc.date.issued2001-07-10en
dc.date.rdate2002-08-16en
dc.date.sdate2001-08-15en
dc.description.abstractThe three insecticides of interest were lindane (an organochlorine), malathion (an organophosphate) and piperonyl butoxide (PBO; a synergist). Based on minimum cytotoxicity (> LC25), the following concentrations were chosen for the pesticide mixture studies: 70μM lindane (Lind), 50μM malathion (Mal) and 55μM PBO. In the AlamarBlue cytotoxicity assay, individual pesticide and mixtures of malathion/PBO (MP) and malathion/lindane (ML) prompted cytotoxicity with varying intensities (Mal 18.8%, Lind 20.4%, PBO 23.5%, ML 53.6% and MP 64.9%). Cytopathological analysis revealed apoptotic features in treated cells and the DNA Ladder Assay confirmed the presence of DNA fragments. The specific mode of cell death was examined via the 7-aminoactinomycin D (7-AAD) Staining Assay. Apoptosis was detected in each treatment (Mal 6.5%, Lind 12.0%, PBO 13.2%, ML 19.3% and MP 23.4%). Furthermore, 7-AAD staining in combination with fluorescent-labeled monoclonal antibodies, PE-CD45RB/220 and FITC-CD90, was performed. B-cells were more susceptible to Mal and PBO treatments than were T-cells. The pro-oxidant activity of the pesticides was monitored via the Dichlorofluorescin Diacetate assay. Exposure to pesticides for 15 minutes increased H2O2 production above the controls, Mal 21.1%; Lind 10.8%; PBO 25.9%; ML 26.8%; MP 37.8%. The activities of antioxidant enzymes, glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were altered by these treatments. GR was significantly reduced for the pesticide mixtures only (control: 51.7; Mal: 48.2; Lind: 50; PBO: 52.3; ML: 40.5; MP: 42 Units/mg). GSH-Px activity was severely reduced for all the pesticide treatments (control: 44.9; Mal: 30.2; Lind: 30.6; PBO: 32.4; ML: 21.1; MP: 21.1 Units/mg). These results indicate that exposure to these pesticide and pesticide mixtures induces apoptosis and oxidative stress.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-08152001-144213en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08152001-144213/en
dc.identifier.urihttp://hdl.handle.net/10919/34547en
dc.publisherVirginia Techen
dc.relation.haspartThesisFinalETDver2.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectantioxidant enzymesen
dc.subjectpesticidesen
dc.subjectlindaneen
dc.subjectmalathionen
dc.subjectpiperonyl butoxideen
dc.subjectApoptosisen
dc.subjectsplenocytesen
dc.subjectin vitroen
dc.subjectsuperoxide dismutaseen
dc.subjectglutathione peroxidaseen
dc.subjectimmune cellsen
dc.subjectcatalaseen
dc.subjectglutathione reductaseen
dc.subjectcytotoxicityen
dc.subjectchemical mixturesen
dc.subjectoxidative stressen
dc.titlePesticide Mixtures Induce Immunotoxicity: Potentiation of Apoptosis and Oxidative Stressen
dc.typeThesisen
thesis.degree.disciplineBiomedical Sciences and Pathobiologyen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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