Effect of low-level laser therapy on hemorrhagic lesions induced by immune complex in rat lungs.
OBJECTIVE
The aim of this study was to investigate if low-level laser therapy (LLLT) can modulate formation of hemorrhagic lesions induced by immune complex.


BACKGROUND
There is a lack of information on LLLT effects in hemorrhagic injuries of high perfusion organs, and the relative efficacy of LLLT compared to anti-inflammatory drugs.


METHODS
A controlled animal study was undertaken with 49 male Wistar rats randomly divided into seven groups. Bovine serum albumin (BSA) i.v. was injected through the trachea to induce an immune complex lung injury. The study compared the effect of irradiation by a 650-nm Ga-Al-As laser with LLLT doses of 2.6 Joules/cm(2) to celecoxib, dexamethasone, and control groups for hemorrhagic index (HI) and myeloperoxide activity (MPO) at 24 h after injury.


RESULTS
The HI for the control group was 4.0 (95% CI, 3.7-4.3). Celecoxib, LLLT, and dexamethasone all induced significantly (p < 0.01) lower HI than control animals at 2.5 (95% CI, 1.9-3.1), 1.8 (95% CI, 1.2-2.4), and 1.5 (95% CI, 0.9-2.1), respectively, for all comparisons to control. Dexamethasone, but not celecoxib, induced a slightly, but significantly lower HI than LLLT (p = 0.04). MPO activity was significantly decreased in groups receiving celecoxib at 0.87 (95% CI, 0.63-1.11), dexamethasone at 0.50 (95% CI, 0.24-0.76), and LLLT at 0.7 (95% CI, 0.44-0.96) when compared to the control group, at 1.6 (95% CI, 1.34-1.96; p < 0.01), but there were no significant differences between any of the active treatments.


CONCLUSIONS
LLLT at a dose of 2.6 Joules/cm(2) induces a reduction of HI levels and MPO activity in hemorrhagic injury that is not significantly different from celecoxib. Dexamethasone is slightly more effective than LLLT in reducing HI, but not MPO activity.
Aimbire
F
F
Laboratory of Animal Experimentation, Research and Development Institute (IP&D), Vale do Paraíba University (UNIVAP), São José dos Campos, Brazil.
Lopes-Martins
R A B
RA
Albertini
R
R
Pacheco
M T T
MT
Castro-Faria-Neto
H C
HC
Martins
P S L L
PS
Bjordal
J M
JM
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000068579:Celecoxib; D003907:Dexamethasone / Q000494:pharmacology; D006470:Hemorrhage / Q000188:drug therapy / Q000209:etiology / Q000532:radiotherapy*; D007105:Immune Complex Diseases / Q000150:complications*; D028022:Low-Level Light Therapy; D008171:Lung Diseases / Q000188:drug therapy / Q000209:etiology / Q000532:radiotherapy*; D008297:Male; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013449:Sulfonamides / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D011720:Pyrazoles; D013449:Sulfonamides; D003907:Dexamethasone; D000068579:Celecoxib