title: Investigate the chronic neurotoxic effects of diquat.
abstract: Chronic exposure to agricultural chemicals (pesticides/herbicides) has been shown to induce neurotoxic effects or results in accumulation of various toxic metabolic by-products. These substances have the relevant ability to cause or increase the risk for neurodegeneration. Diquat is an herbicide that has been extensively used in the United States of America and other parts of the world. Diquat is constantly released into the environment during its use as a contact herbicide. Diquat structurally resembles 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) and paraquat. Rotenone, paraquat, maneb and MPTP reproduce features of movement disorders in experimental animal models. Based on the structural similarity to other neurotoxins, chronic exposure of diquat can induce behavioral and neurochemical alterations associated with dopaminergic neurotoxicity. However, in the present study, diquat unlike other neurotoxins (rotenone, 6-hydroxydopamine, MPTP, paraquat and maneb) did not induce dopamine depletion in the mouse striatum. Although, notable exacerbation in motor impairment (swimming score, akinesia and open field) were evident that may be due to the decreased dopamine turnover and mild nigrostriatal neurodegeneration. These data indicate that, despite the apparent structural similarity to other dopaminergic neurotoxins, diquat did not exert severe deleterious effects on dopamine neurons in a manner that is unique to rotenone and MPTP.
authors.affiliation: Division of Pharmacology and Toxicology, Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA.
authors.forename: Senthilkumar S
authors.initials: SS
authors.lastname: Karuppagounder
authors.forename: Manuj
authors.initials: M
authors.lastname: Ahuja
authors.forename: Manal
authors.initials: M
authors.lastname: Buabeid
authors.forename: Koodeswaran
authors.initials: K
authors.lastname: Parameshwaran
authors.forename: Engy
authors.initials: E
authors.lastname: Abdel-Rehman
authors.forename: Vishnu
authors.initials: V
authors.lastname: Suppiramaniam
authors.forename: Muralikrishanan
authors.initials: M
authors.lastname: Dhanasekaran
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004178:Diquat / Q000633:toxicity*; D004298:Dopamine / Q000378:metabolism; D006540:Herbicides / Q000633:toxicity*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012701:Serotonin / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D006540:Herbicides; D012701:Serotonin; D004178:Diquat; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine