title: Manganese alters rat brain amino acids levels.
abstract: Manganese (Mn) is an essential element and it acts as a cofactor for a number of enzymatic reactions, including those involved in amino acid, lipid, protein, and carbohydrate metabolism. Excessive exposure to Mn can lead to poisoning, characterized by psychiatric disturbances and an extrapyramidal disorder. Mn-induced neuronal degeneration is associated with alterations in amino acids metabolism. In the present study, we analyzed whole rat brain amino acid content subsequent to four or eight intraperitoneal injections, with 25 mg MnCl₂/kg/day, at 48-h intervals. We noted a significant increase in glycine brain levels after four or eight Mn injections (p < 0.05 and p < 0.01, respectively) and arginine also after four or eight injections (p < 0.001). Significant increases were also noted in brain proline (p < 0.01), cysteine (p < 0.05), phenylalanine (p < 0.01), and tyrosine (p < 0.01) levels after eight Mn injections vs. the control group. These findings suggest that Mn-induced alterations in amino acid levels secondary to Mn affect the neurochemical milieu.
authors.affiliation: I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal. apsantos@ff.ul.pt
authors.forename: Dinamene
authors.initials: D
authors.lastname: Santos
authors.forename: M Camila
authors.initials: MC
authors.lastname: Batoreu
authors.forename: Isabel
authors.initials: I
authors.lastname: Almeida
authors.forename: Ruben
authors.initials: R
authors.lastname: Ramos
authors.forename: M
authors.initials: M
authors.lastname: Sidoryk-Wegrzynowicz
authors.forename: Michael
authors.initials: M
authors.lastname: Aschner
authors.forename: A P
authors.initials: AP
authors.lastname: Marreilha dos Santos
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects*; D002712:Chlorides / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D005116:Extrapyramidal Tracts / Q000187:drug effects / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008297:Male; D008345:Manganese / Q000032:analysis; D017895:Manganese Compounds / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics; D020149:Manganese Poisoning / Q000378:metabolism*; D019636:Neurodegenerative Diseases / Q000209:etiology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D020258:Neurotoxicity Syndromes / Q000378:metabolism* / Q000503:physiopathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D015854:Up-Regulation / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002712:Chlorides; D017895:Manganese Compounds; D008345:Manganese; D005680:gamma-Aminobutyric Acid; C025340:manganese chloride