The effects of low laser irradiation on angiogenesis in injured rat tibiae

• Autor(a) principal: Garavello, I. [UNESP]
• Data de Publicação: 2004
• Outros Autores: Baranauskas, V., Da Cruz-Höfling, Maria Alice
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/67615
• topic: Angiogenesis; Bone wound healing; He-Ne laser; Rat; Tibia; angiogenesis; animal experiment; animal model; animal tissue; bone injury; bone marrow; bone matrix; bone regeneration; comparative study; controlled study; cortical bone; density; diaphysis; helium neon laser; histology; low level laser therapy; male; microscopy; molecular dynamics; nonhuman; quantitative analysis; radiation dose; rat; tibia; wound healing; Animals; Helium; Laser Therapy, Low-Level; Lasers; Male; Neon; Neovascularization, Physiologic; Rats; Rats, Wistar; Time Factors; Wound Healing; Animalia

The influence of He-Ne laser radiation on the formation of new blood vessels in the bone marrow compartment of a regenerating area of the mid-cortical diaphysis of the tibiae of young adult rats was studied. A small hole was surgically made with a dentistry burr in the tibia and the injured area received a daily laser therapy over 7 or 14 days transcutaneously starting 24 h from surgery. Incident energy density dosages of 31.5 and 94.5 Jcm-2 were applied during the period of the tibia wound healing investigated. Light microscopic examination of histological sections of the injured area and quantification of the newly-formed blood vessels were undertaken. Low-level energy treatment accelerated the deposition of bone matrix and histological characteristics compatible with an active recovery of the injured tissue. He-Ne laser therapy significantly increased the number of blood vessels after 7 days irradiation at an energy density of 94.5 Jcm-2, but significantly decreased the number of vessels in the 14-day irradiated tibiae, independent of the dosage. These effects were attributed to laser treatment, since no significant increase in blood vessel number was detected between 8 and 15 non-irradiated control tibiae. Molecular mechanisms involved in low-level laser therapy of angiogenesis in post-traumatic bone regeneration needs further investigation.