Related Experiment Video
Updated: Mar 26, 2026
Mouse Model of Oleic Acid-Induced Acute Respiratory Distress Syndrome
Published on: June 2, 2022
Effects of methylene blue in acute lung injury induced by oleic acid in rats
Ana Paula Cassiano Silveira1, Daniella Alves Vento1, Agnes Afrodite Sumarelli Albuquerque1
11 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.
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.
