Efeito da fotobiomodulação e/ou tratamento hormonal no reparo ósseo de ratas ovariectomizadas

Abstract

Bone injuries are more frequent in postmenopausal women and in the elderly due to lack of estrogen hormone, which causes a decrease in bone density. Some experi- mental studies have shown that Photobiomodulation (PBM) could be an interesting therapy to aid in bone repair without known side effects. The aim of this study was to evaluate the effects of Hormonal (H) treatment with Estrogen and Progenterone and Photobiomodulation (PBM) therapy, used independently and associated in the bone repair process after induction of the tibial Injury (I) of ovariectomized rats (OVX). Ma- terials and Methods: were used 28 Wistar rats aged 75-105 days, weighing between 193-233g and distributed randomly in the following groups: G1: Sham; G2: I; G3: CTL (OVX) ; G4: NT (OVX+ I); G5: H (OVX+I+H - equivalent to 280 µg/kg of 17β estradiol in single-dose I.M.); G6: PBM (OVX+I+PBM - 808nm, 60s, 6J; 100mW) and G7: H+PBM (OVX+I+H+PBM). After 7 days of ovariectomy, bone lesion will be induced in both tibias and 30 days after injury the animals were euthanized. The tibias and blood were collected for analysis: Mechanical properties (MP), Morphology (histology) and Biochemistry (alkaline phosphatase (ALP), tartarate resistant acid phosphatase (ACP)). Results: All groups with ovariectomy presented reduction in MP when com- pared to the CTL group. The NT group presented worsening in the MP and a higher delay in bone repair. The groups treated with H and PBM presented better organization in the bone tissue, with results similar to the tissue without injury in the OVX rats. Con- clusion: The use of PBM therapy associated with hormonal treatment maintained the improvement of bone repair and considering the analgesic and anti-inflammatory ef- fects of PBM, the use of this association (H+PBM) could be interesting for the treatment of bone lesions.