Effects of 830-nm laser light on preventing bone loss after ovariectomy.
OBJECTIVE
The aim of this study was to investigate the effects of low-level laser therapy (LLLT; infrared, 830 nm) on the bone properties and bone strength of rat femora after ovariectomy (OVX).


BACKGROUND
Osteoporosis affects 30% of postmenopausal women, and it has been recognized as a major public health problem. Based on the stimulatory effects of LLLT on proliferation of bone cells, we hypothesized that LLLT would be efficient in preventing bone mass loss in OVX rats.


METHODS
Forty female rats were divided into four groups: sham-operated control (SC), OVX control (OC), sham-operated irradiated at a dose of 120 J/cm(2) (I120), and OVX irradiated at a dose of 120 J/cm(2) (O120). Animals were operated at the age of 90 days. Laser irradiation was initiated 1 day after the operation and was performed three times a week, for 2 months. Femora were submitted to a biomechanical test and a physical properties evaluation.


RESULTS
Maximal load of O120 was higher than in control groups. Wet weight, dry weight, and bone volume of O120 did not show any difference when compared with SC.


CONCLUSIONS
The results of the present study indicate that LLLT was able to prevent bone loss after OVX in rats. However, further studies are needed to investigate the effects of different parameters, wavelengths, and sessions of applications on OVX rats.
Renno
Ana Claudia Muniz
AC
Department of Physiotherapy, Federal University of São Carlos, São Carlos, Brazil.
de Moura
Fernanda Mendes
FM
dos Santos
Nádia Slemer Andrade
NS
Tirico
Renata Passarelli
RP
Bossini
Paulo Sérgio
PS
Parizotto
Nivaldo Antonio
NA
D000818:Animals; D015519:Bone Density / Q000528:radiation effects; D005260:Female; D005269:Femur / Q000528:radiation effects; D007834:Lasers; D009929:Organ Size / Q000528:radiation effects; D010024:Osteoporosis / Q000517:prevention & control*; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar