title: Effects of acute and chronic administration of methylprednisolone on oxidative stress in rat lungs.
abstract: OBJECTIVE
  To determine the effects of acute and chronic administration of methylprednisolone on oxidative stress, as quantified by measuring lipid peroxidation (LPO) and total reactive antioxidant potential (TRAP), in rat lungs.
  
  
  METHODS
  Forty Wistar rats were divided into four groups: acute treatment, comprising rats receiving a single injection of methylprednisolone (50 mg/kg i.p.); acute control, comprising rats i.p. injected with saline; chronic treatment, comprising rats receiving methylprednisolone in drinking water (6 mg/kg per day for 30 days); and chronic control, comprising rats receiving normal drinking water.
  
  
  RESULTS
  The levels of TRAP were significantly higher in the acute treatment group rats than in the acute control rats, suggesting an improvement in the pulmonary defenses of the former. The levels of lung LPO were significantly higher in the chronic treatment group rats than in the chronic control rats, indicating oxidative damage in the lung tissue of the former.
  
  
  CONCLUSIONS
  Our results suggest that the acute use of corticosteroids is beneficial to lung tissue, whereas their chronic use is not. The chronic use of methylprednisolone appears to increase lung LPO levels.
authors.affiliation: Hospital Divina Providência, Porto Alegre, Brazil.
authors.forename: Ronaldo Lopes
authors.initials: RL
authors.lastname: Torres
authors.affiliation: Department of Pharmacology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Iraci Lucena da Silva
authors.initials: IL
authors.lastname: Torres
authors.affiliation: Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Laste
authors.affiliation: Department of Pharmacology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Maria Beatriz Cardoso
authors.initials: MB
authors.lastname: Ferreira
authors.affiliation: Department of Pharmacology, Heart Institute, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Paulo Francisco Guerreiro
authors.initials: PF
authors.lastname: Cardoso
authors.affiliation: Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Adriane
authors.initials: A
authors.lastname: Belló-Klein
mesh_terms: D000818:Animals; D061745:Antioxidant Response Elements; D004195:Disease Models, Animal; D005938:Glucocorticoids / Q000008:administration & dosage*; D015227:Lipid Peroxidation; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage*; D018384:Oxidative Stress / Q000187:drug effects*; D017208:Rats, Wistar
chemical_list: D005938:Glucocorticoids; D008775:Methylprednisolone