Assessment of cytoskeleton and endoplasmic reticulum of fibroblast cells subjected to low-level laser therapy and low-intensity pulsed ultrasound.
OBJECTIVE
The aim of the present study was to compare the effect of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on the cytoskeleton and endoplasmic reticulum of L929 cells. Thermal and non-thermal physical mechanisms such as LLLT and LIPUS induce clinically significant responses in cells, tissues, and organs.


METHODS
L929 fibroblast cell cultures were irradiated with LLLT and subjected to LIPUS. Cultures irradiated with the laser (904 nm) were divided into three groups: group I, control (no irradiation); group II, irradiated at 6 J/cm(2); and group III, irradiated at 50 mJ/cm(2). Cultures subjected to ultrasound were divided into five groups: group I, control (no LIPUS); group II, LIPUS at 0.2 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group III, LIPUS at 0.6 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group IV, LIPUS at 0.2 W/cm(2) in pulsed mode at 20% (2:8 duty cycle); and group V, LIPUS at 0.6 W/cm(2) in pulsed mode at 20% (2:8 duty cycle). Each group was irradiated at 24-h intervals, with the following post-treatment incubation times: 24, 48, and 72 h. The effects of LLLT and LIPUS on the cytoskeleton and endoplasmic reticulum was evaluated by the use of fluorescent probes and with fluorescence microscopy analysis.


RESULTS
The results following LLLT and LIPUS demonstrate that ultrasound was more effective than laser on fibroblast cell cultures when the endoplasmic reticulum was assessed, whereas there was a better distribution of the filaments of the cytoskeleton in the cells subjected to laser irradiation.


CONCLUSIONS
The study demonstrated that both LLLT and LIPUS promote changes on the cellular level. However, LIPUS was more effective than LLLT at the doses used here, as assessed by fluorescence microscopy, which revealed increased reticulum activity and increased protein synthesis. However, when the organization of actin filaments was assessed, LLLT achieved a better result.
Oliveira
Deise A A Pires
DA
Laboratório de Dinâmica de Compartimento Celular, Instituto de Pesquisa e Desenvolvimento (IP&D), UNIVAP, São José dos Campos, São Paulo, Brazil.
De Oliveira
Rodrigo Franco
RF
Magini
Márcio
M
Zangaro
Renato Amaro
RA
Soares
Cristina Pacheco
CP
D000818:Animals; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000528:radiation effects*; D004721:Endoplasmic Reticulum / Q000528:radiation effects*; D005347:Fibroblasts / Q000528:radiation effects*; D028022:Low-Level Light Therapy; D051379:Mice; D008856:Microscopy, Fluorescence; D014464:Ultrasonic Therapy