title: Hippocampus lipid peroxidation induced by residual oil fly ash intranasal instillation versus habituation to the open field.
abstract: Epidemiological studies have demonstrated the adverse effects of particulate matter (PM) inhalation on the respiratory and cardiovascular systems. It has been reported that air pollution may affect the central nervous system and decrease cognitive function. In rats, residual oil fly ash (ROFA) instillation causes decreased motor activity and increased lipid peroxidation in the striatum and the cerebellum. Our objective was to determine whether chronic instillation of particles induces changes in learning and memory in rats and whether oxidants in the hippocampus may contribute to these adverse effects. Forty-five-day-old male Wistar rats were exposed to ROFA by intranasal instillation and were treated with N-acetylcysteine (NAC) at 150 mg/kg i.p. for 30 days. Control groups were exposed to ROFA, NAC, or neither. On days 1, 8, and 30 of the protocol, rats were submitted to the open field test to evaluate habituation. After the last open field session, the rats were killed by decapitation. The hippocampus was used to determine lipid peroxidation (LP) by the thiobarbituric acid-reactive substances test. ROFA instillation induced an increase in LP in the hippocampus compared to all treatment groups (p = .012). NAC treatment blocked these changes. All of the treatment groups presented a decrease in the frequency of peripheral walking (p = .001), rearing (p = .001), and exploration (p = .001) over time. Our study demonstrates that exposure to particles for 30 days and/or NAC treatment do not modify habituation to an open field, a simple form of learning and memory in rats, and that oxidative damage induced by ROFA does not modulate these processes.
authors.affiliation: Post-Graduate Course in Medical Sciences and Laboratory of Oxidative Stress and Atmospheric Pollution, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Zanchi
authors.forename: Mitiko
authors.initials: M
authors.lastname: Saiki
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Helena Maria Tannhauser
authors.initials: HM
authors.lastname: Barros
authors.forename: Claudia Ramos
authors.initials: CR
authors.lastname: Rhoden
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000281:Administration, Intranasal; D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D002244:Carbon / Q000633:toxicity*; D060729:Coal Ash; D004336:Drug Antagonism; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D016166:Free Radical Scavengers / Q000494:pharmacology; D006185:Habituation, Psychophysiologic / Q000187:drug effects* / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008568:Memory / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D052638:Particulate Matter / Q000633:toxicity*; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000393:Air Pollutants; D060729:Coal Ash; D016166:Free Radical Scavengers; D052638:Particulate Matter; D008315:Malondialdehyde; D002244:Carbon; D000111:Acetylcysteine