title: Effects of exposure to amitraz on noradrenaline, serotonin and dopamine levels in brain regions of 30 and 60 days old male rats.
abstract: The effects of amitraz oral exposure (20, 50 and 80mg/kg bw, 5 days) on brain region monoamine levels of male rats at 30 and 60 days of age were examined. The amitraz-treated rats at the oral doses of 20 and 50mg/kg bw had no visible injury, i.e., any clinical signs of dysfunction observed in any of the animals. However, rats treated with amitraz at the highest dose (80mg/kg bw, 5 days) showed a slight motor incoordination after 1-2h of treatment. These signs were reversible approximately at 6h after dose. After the last dose of amitraz, NE, DA and 5-HT and its metabolites levels were determined in the brain regions hypothalamus, midbrain, prefrontal cortex, striatum and hippocampus by HPLC. Amitraz caused changes in the NE, DA and 5-HT and their metabolite levels in a brain regional-, dose- and age-related manner. In the brain regions studied, amitraz induced a statistically significant increase in 5-HT, NE and DA content with age interaction, but the NE increases in prefrontal cortex and hippocampus was without age interaction. Moreover, in the brain regions studied, amitraz induced a statistically significant decrease in the metabolite 5-HIAA, MHPG, DOPAC and HVA levels displaying an age interaction, excepting the 5-HIAA decrease in midbrain and the DOPAC decrease in hypothalamus and striatum which were without age interaction. Furthermore, amitraz evoked a statistically significant decrease in 5-HT, NE and DA turnover in the brain regions studied. The present findings indicate that amitraz significantly altered CNS monoaminergic neurotransmitters in a brain regional-, dose- and age-related manner.
authors.affiliation: Department of Toxicology and Pharmacology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040 Madrid, Spain. jdelpino@pdi.ucm.es
authors.forename: J
authors.initials: J
authors.lastname: Del Pino
authors.forename: M A
authors.initials: MA
authors.lastname: Martínez
authors.forename: V
authors.initials: V
authors.lastname: Castellano
authors.forename: E
authors.initials: E
authors.lastname: Ramos
authors.forename: M R
authors.initials: MR
authors.lastname: Martínez-Larrañaga
authors.forename: A
authors.initials: A
authors.lastname: Anadón
mesh_terms: D000367:Age Factors; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D014052:Toluidines / Q000633:toxicity*
chemical_list: D014052:Toluidines; D012701:Serotonin; C014983:amitraz; D004298:Dopamine; D009638:Norepinephrine