title: Low-level laser therapy (LLLT) acts as cAMP-elevating agent in acute respiratory distress syndrome.
abstract: The aim of this work was to investigate if the low-level laser therapy (LLLT) on acute lung inflammation (ALI) induced by lipopolysaccharide (LPS) is linked to tumor necrosis factor (TNF) in alveolar macrophages (AM) from bronchoalveolar lavage fluid (BALF) of mice. LLLT has been reported to actuate positively for relieving the late and early symptoms of airway and lung inflammation. It is not known if the increased TNF mRNA expression and dysfunction of cAMP generation observed in ALI can be influenced by LLLT. For in vivo studies, Balb/c mice (n = 5 for group) received LPS inhalation or TNF intra nasal instillation and 3 h after LPS or TNF-α, leukocytes in BALF were analyzed. LLLT administered perpendicularly to a point in the middle of the dissected bronchi with a wavelength of 660 nm and a dose of 4.5 J/cm(2). The mice were irradiated 15 min after ALI induction. In vitro AM from mice were cultured for analyses of TNF mRNA expression and protein and adenosine3':5'-cyclic monophosphate (cAMP) levels. One hour after LPS, the TNF and cAMP levels in AM were measured by ELISA. RT-PCR was used to measure TNF mRNA in AM. The LLLT was inefficient in potentiating the rolipram effect in presence of a TNF synthesis inhibitor. LLLT attenuated the neutrophil influx and TNF in BALF. In AM, the laser increased the cAMP and reduced the TNF-α mRNA. LLLT increases indirectly the cAMP in AM by a TNF-dependent mechanism.
authors.affiliation: Research and Development Institute - IP&D, Av. Shishima Hifumi, 2911 - Urbanova, Po Box 12244-00, São José dos Campos, SP, Brazil.
authors.forename: Flávia Mafra
authors.initials: FM
authors.lastname: de Lima
authors.forename: Leonardo M
authors.initials: LM
authors.lastname: Moreira
authors.forename: A B
authors.initials: AB
authors.lastname: Villaverde
authors.forename: Regiane
authors.initials: R
authors.lastname: Albertini
authors.forename: Hugo C
authors.initials: HC
authors.lastname: Castro-Faria-Neto
authors.forename: Flávio
authors.initials: F
authors.lastname: Aimbire
mesh_terms: D000818:Animals; D001483:Base Sequence; D000242:Cyclic AMP / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004195:Disease Models, Animal; D008070:Lipopolysaccharides / Q000633:toxicity; D028022:Low-Level Light Therapy; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D058988:Phosphodiesterase 4 Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000532:radiotherapy*; D020889:Rolipram / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D008070:Lipopolysaccharides; D058988:Phosphodiesterase 4 Inhibitors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000242:Cyclic AMP; D020889:Rolipram