Effect of laser therapy on skeletal muscle repair process in diabetic rats

Author(s)

Franca, Cristiane Miranda ^[1] ; Santana, Cristiano de Loura ^[1] ; Takahashi, Camila Borin ^[2] ; Alves, Agnelo Neves ^[1] ; De Souza Mernick, Ana Paula ^[2] ; Santos Fernandes, Kristianne Porta ^[1] ; Teixeira da Silva, Daniela de Fatima ^[1] ; Bussadori, Sandra Kalil ^[3] ; Mesquita-Ferrari, Raquel Agnelli ^[1]

Affiliation

^[1] Univ Nove de Julho, Postgrad Program Biophoton Appl Hlth Sci, BR-01504001 Sao Paulo - Brazil

^[2] Univ Nove de Julho, Sch Dent, BR-01504001 Sao Paulo - Brazil

^[3] Univ Nove de Julho, Postgrad Program Rehabil Sci, BR-01504001 Sao Paulo - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 28, n. 5, p. 1331-1338, SEP 2013.
• Web of Science Citations: 16

Abstract

Skeletal muscle myopathy is a common source of disability in diabetic patients. This study evaluated whether low-level laser therapy (LLLT) influences the healing morphology of injured skeletal muscle. Sixty-five male Wistar rats were divided as follows: (1) sham; (2) control; (3) diabetic; (4) diabetic sham; (5) nondiabetic cryoinjured submitted to LLLT (LLLT); (6) diabetic cryoinjured submitted to LLLT (D-LLLT); and (7) diabetic cryoinjured non-treated (D). Diabetes was induced with streptozotocin. Anterior tibialis muscle was cryoinjured and received LLLT daily (780 nm, 5 J/cm(2), 10 s per point; 0.2 J; total treatment, 1.6 J). Euthanasia occurred on day 1 in groups 1, 2, 3, and 4 and on days 1, 7, and 14 in groups 5, 6, and 7. Muscle samples were processed for H\&E and Picrosirius Red and photographed. Leukocytes, myonecrosis, fibrosis, and immature fibers were manually quantified using the ImageJ software. On day 1, all cryoinjured groups were in the inflammatory phase. The D group exhibited more myonecrosis than LLLT group (p < 0.05). On day 14, the LLLT group was in the remodeling phase; the D group was still in the proliferative phase, with fibrosis, chronic inflammation, and granulation tissue; and the D-LLLT group was in an intermediary state in relation to the two previous groups. Under polarized light, on day 14, the LLLT and D-LLLT groups had organized collagen bundles in the perimysium, whereas the diabetic groups exhibited fibrosis. LLLT can have a positive effect on the morphology of skeletal muscle during the tissue repair process by enhancing the reorganization of myofibers and the perimysium, reducing fibrosis. (AU)

• FAPESP's process: 11/04452-8 - Photobiomodulation on regulatory myogenic factors expression during skeletal muscle repair following cryolesion in rats
• Grantee: Agnelo Neves Alves
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 11/20867-3 - Immunolocalization of skeletal muscle laminin and fibronectin in the healing process of diabetic rats treated with low level lasertherapy
• Grantee: Camila Borin Takahashi
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 11/17638-2 - Effects of low level laser on regulatory myogenic factors expression and matrix metalloprotease 2 activity during skeletal muscle repair following cryolesion in rats
• Grantee: Raquel Agnelli Mesquita Ferrari
• Support Opportunities: Regular Research Grants