title: Effects of methylene blue in acute lung injury induced by oleic acid in rats.
abstract: BACKGROUND
  In acute lung injury (ALI), rupture of the alveolar-capillary barrier determines the protein-rich fluid influx into alveolar spaces. Previous studies have reported that methylene blue (MB) attenuates such injuries. This investigation was carried out to study the MB effects in pulmonary capillary permeability.
  
  
  METHODS
  Wistar rats were divided into five groups: (I) Sham: saline bolus; (II) MB, MB infusion for 2 h; (III) oleic acid (OA), OA bolus; (IV) MB/OA, MB infusion for 2 h, and at 5 min after from the beginning, concurrently with an OA bolus; and (V) OA/MB, OA bolus, and after 2 h, MB infusion for 2 h. After 4 h, blood, bronchoalveolar lavage (BAL), and lung tissue were collected from all groups for analysis of plasma and tissue nitric oxide, calculation of the wet weight to dry weight ratio (WW/DW), and histological examination of lung tissue. Statistical analysis was performed using nonparametric test.
  
  
  RESULTS
  Although favourable trends have been observed for permeability improvement parameters (WW/WD and protein), the results were not statistically significant. However, histological analysis of lung tissue showed reduced lesion areas in both pre- and post-treatment groups.
  
  
  CONCLUSIONS
  The data collected using this experimental model was favourable only through macroscopic and histological analysis. These observations are valid for both MB infusions before or after induction of ALI.
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Ana Paula
authors: AP
authors: Cassiano Silveira
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Daniella Alves
authors: DA
authors: Vento
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Agnes Afrodite Sumarelli
authors: AA
authors: Albuquerque
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Andrea Carla
authors: AC
authors: Celotto
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Cristiane
authors: C
authors: Tefé-Silva
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Simone Gusmão
authors: SG
authors: Ramos
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Tales
authors: T
authors: Rubens de Nadai
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Alfredo José
authors: AJ
authors: Rodrigues
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Omero Benedicto
authors: OB
authors: Poli-Neto
authors: 1 Department of Surgery and Anatomy, 2 Department of Pathology, 3 Department of Gynecology and Obstetrics, Ribeirão Preto Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors: Paulo Roberto Barbosa
authors: PR
authors: Evora
keywords: Acute lung injury (ALI); methylene blue (MB); oleic acid (OA); soluble guanylate cyclase (sGC)