Immunolocalization of skeletal muscle laminin and fibronectin in the healing process of diabetic rats treated with low level lasertherapy

Abstract

Skeletal muscle shows a great plasticity and an unique ability to reconstruct themselves when injured. In diabetic individuals there is a delay or complete impairment of repair, because of a lower cellular proliferation and migration, decreased extracellular matrix proteins (ECM) production and because of a unbalance between protein synthesis and proteolysis, seen as in the skeletal muscle as in ECM components. Lasertherapy is a useful option to reestablish tissue homeostasis and to accelerate repair, including in cutaneous wound healing in diabetic patients. The purpose of this study is to evaluate the immune localization of the laminin and fibronectin from rat criolesionated skeletal muscle treated with low-level laser therapy. It will be used 60 male Wistar rats (Rattus novergicus albinus) randomly divided in 6 groups as follows: (1) sham n=5; (2) control n=5; (3) diabetic control n=5; (4) control criolesionated with lasertherapy n=15; (5) diabetic criolesionated n=15; (6) diabetic criolesionated with lasertherapy n=15. Diabetes induction will be performed by an intraperitoneal injection of streptozocin in a unique dose of 50mg/kg. After the onset of hyperglycemia, the animals will be submitted to a criolesion in the anterior tibiallis muscle. Lasertherapy will be administrated daily in 8 points of the lesion (780nm, 5J/cm2, 10s per point; total energy: 3,2J) . The euthanasia will occur at day 1 for the animals from groups 1, 2, and 3, and at days 1, 7, and 14 for the animals of days 4, 5 and 6. The muscle samples will be colleted, fixed in buffered 10% formalin, and routinely processed for hematoxylin and eosin stain to perform the morphological analysis of skeletal muscle repair. Then, it will be done the immunohistochemistry to the spatial and temporal immunolocalization of the laminin and fibronectin. To this, it will be used a light microscope and a reticular grid, and data will be submitted to appropriate statistical analysis.(AU)