Low-level laser therapy restores the oxidative stress balance in acute lung injury induced by gut ischemia and reperfusion

Photochem Photobiol. 2013 Jan-Feb;89(1):179-88. doi: 10.1111/j.1751-1097.2012.01214.x. Epub 2012 Nov 19.


It remains unknown if the oxidative stress can be regulated by low-level laser therapy (LLLT) in lung inflammation induced by intestinal reperfusion (i-I/R). A study was developed in which rats were irradiated (660 nm, 30 mW, 5.4 J) on the skin over the bronchus and euthanized 2 h after the initial of intestinal reperfusion. Lung edema and bronchoalveolar lavage fluid neutrophils were measured by the Evans blue extravasation and myeloperoxidase (MPO) activity respectively. Lung histology was used for analyzing the injury score. Reactive oxygen species (ROS) was measured by fluorescence. Both expression intercellular adhesion molecule 1 (ICAM-1) and peroxisome proliferator-activated receptor-y (PPARy) were measured by RT-PCR. The lung immunohistochemical localization of ICAM-1 was visualized as a brown stain. Both lung HSP70 and glutathione protein were evaluated by ELISA. LLLT reduced neatly the edema, neutrophils influx, MPO activity and ICAM-1 mRNA expression. LLLT also reduced the ROS formation and oppositely increased GSH concentration in lung from i-I/R groups. Both HSP70 and PPARy expression also were elevated after laser irradiation. Results indicate that laser effect in attenuating the acute lung inflammation is driven to restore the balance between the pro- and antioxidants mediators rising of PPARy expression and consequently the HSP70 production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Lung Injury / metabolism
  • Acute Lung Injury / pathology
  • Acute Lung Injury / radiotherapy*
  • Animals
  • Bronchoalveolar Lavage Fluid / cytology
  • Cell Count
  • Gene Expression Regulation
  • Glutathione / biosynthesis
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / metabolism
  • Intestinal Mucosa / metabolism
  • Intestines / pathology
  • Intestines / radiation effects*
  • Low-Level Light Therapy*
  • Lung / metabolism
  • Lung / pathology
  • Lung / radiation effects*
  • Male
  • Neutrophils / pathology
  • Oxidative Stress
  • PPAR gamma / genetics
  • PPAR gamma / metabolism
  • Peroxidase / metabolism
  • Pulmonary Edema / metabolism
  • Pulmonary Edema / pathology
  • Pulmonary Edema / radiotherapy*
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / pathology
  • Reperfusion Injury / radiotherapy*


  • HSP70 Heat-Shock Proteins
  • PPAR gamma
  • Reactive Oxygen Species
  • Intercellular Adhesion Molecule-1
  • Peroxidase
  • Glutathione