PP107

• Published in: Oral oncology Vol. 49; p. S130
• Main Authors: Paraguassú, Gardênia Matos, Vasconcelos, Rebeca Mota, Uzêda e Silva, Virgı́nia Dias, Aquino Xavier, Flávia Calo, dos Santos, Jean Nunes, Rodriguez, Tânia Tavares, Pedreira Ramalho, Maria José, Barbosa Pinheiro, Antônio Luiz, Pedreira Ramalho, Luciana Maria
• Format: Journal Article
• Language: English
• Published: 01-05-2013
• Subjects: Hematology, Oncology and Palliative Medicine; Otolaryngology
• ISSN: 1368-8375
• DOI: 10.1016/j.oraloncology.2013.03.350

Purpose Thyroid hormone deficiency has been associated to disruption of the body’s metabolism, including healing process. Laser phototherapy has been shown to be effective in improving wound healing, but their usefulness in the improvement of hypothyroidism wound healing remains unknown. Material and methods Under general anesthesia, a standard surgical wound (1 cm2 ) was created on the dorsum of 48 male Wistar rats divided into four groups of 12 animals each: EC-Control Euthyroid; EL-Euthyroid + Laser; HC-Control Hypothyroid and HL-Hypothyroid + Laser. The irradiation with Laser light GaAlAs ( λ 660 nm, 40 mW, CW, 0.04 cm2 , 24 J/cm2 per session, Twin Flex Evolution®, MMoptics) started immediately after surgery and was repeated every other day for 7 and 14 days. Hypothyroidism was induced in rats with propylthiouracil (0.05 g/100 mL) administered orally for 4 weeks and maintained until the end of the experiment. Animals were killed 8 and 15 days after surgery. Immunohistochemistry for collagen I and III was perfomed with EnVision™. Results Seven days after the surgery, the control euthyroid group (EC), euthyroid and hypothyroid groups irradiated with Laser (EL and HL) showed higher immunoexpression of collagen type I and lower immunoexpression of collagen type III in the newly formed tissue. There were increased imunoexpression of collagen I in the EC, in comparison to HC ( p = 0.019). The immunoexpression of collagen III was significantly lower in irradiated EL than in EC and irradiated HL ( p = 0.047 and p = 0.019, respectively). No significant difference was found in the experimental period of 14 days among the groups. Conclusions Our results indicate that Laser light carried out with the parameters of this investigation increased immunoexpression of collagen type I during tissue repair and improved the quality of newly formed tissue in the presence of hipothyroidism.