title: Environmental tobacco smoke induces oxidative stress in distinct brain regions of infant mice.
abstract: Environmental tobacco smoke (ETS) leads to the death of 600,000 nonsmokers annually and is associated with disturbances in antioxidant enzyme capacity in the adult rodent brain. However, little is known regarding the influence of ETS on brain development. The aim of this study was to determine levels of malonaldehyde (MDA) and 3-nitrotyrosine (3-NT), as well as enzymatic antioxidant activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD), in distinct brain structures. BALB/c mice were exposed to ETS twice daily for 1 h from postnatal day 5 through postnatal day 18. Acute exposure was performed for 1 h on postnatal day 18. Mice were euthanized either immediately (0) or 3 h after the last exposure. Immediately after an acute exposure there were higher GR and GST activities and MDA levels in the hippocampus, higher GPx and SOD activities in the prefrontal cortex, and higher GST activity and MDA levels in the striatum and cerebellum. Three hours later there was an increase in SOD activity and MDA levels in the hippocampus and a decrease in the activity of all enzymes in the prefrontal cortex. Immediately after final repeated exposure there were elevated levels of GST and GR activity and decreased GPx activity in the hippocampus. Moreover, a rise was found in GPx and GST activities in the prefrontal cortex and increased GST and GPx activity in the striatum and cerebellum, respectively. After 3 h the prefrontal cortex showed elevated GR and GST activities, and the striatum displayed enhanced GST activity. Data showed that enzymatic antioxidant system in the central nervous system responds to ETS differently in different regions of the brain and that a form of adaptation occurs after several days of exposure.
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Larissa Helena
authors.initials: LH
authors.lastname: Lobo Torres
authors.forename: Wallace Luiz
authors.initials: WL
authors.lastname: Moreira
authors.forename: Raphael Caio
authors.initials: RC
authors.lastname: Tamborelli Garcia
authors.forename: Raquel
authors.initials: R
authors.lastname: Annoni
authors.forename: Ana Laura
authors.initials: AL
authors.lastname: Nicoletti Carvalho
authors.forename: Simone Aparecida
authors.initials: SA
authors.lastname: Teixeira
authors.forename: Maurílio
authors.initials: M
authors.lastname: Pacheco-Neto
authors.forename: Marcelo Nicolas
authors.initials: MN
authors.lastname: Muscará
authors.forename: Rosana
authors.initials: R
authors.lastname: Camarini
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: de Melo Loureiro
authors.forename: Mauricio
authors.initials: M
authors.lastname: Yonamine
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
authors.forename: Tania
authors.initials: T
authors.lastname: Marcourakis
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants; D001921:Brain / Q000187:drug effects*; D002248:Carbon Monoxide / Q000737:chemistry; D002263:Carboxyhemoglobin; D003367:Cotinine / Q000097:blood; D015227:Lipid Peroxidation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D009538:Nicotine / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects*; D012906:Smoke / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D000975:Antioxidants; D012906:Smoke; D014028:Tobacco Smoke Pollution; D009538:Nicotine; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin; D003367:Cotinine