Modelo de indução de tendinose de aquiles em ratos : estudo histomorfométrico

Abstract

The tendon diseases are major causes of injury in athletes undergoing excessive training. The tendinosis is one of these lesions and is characterized histologically for a hyper cellularity and increased deposition of type III collagen. There are several possible models of tendinosis induction in animals, being most effective in the mechanical reproduction of the events involved in this process. Because the driving characteristic of the hind legs, one incline of the treadmill used in the 10 degrees (acclivity) induction is necessary. The running speed, which the animals were submitted in previous models, is a factor difficult to reproduce. There is need for standardization of model induction Achilles tendinosis, reproducible. The purpose is to define and validate a model for the induction of Achilles tendinosis in rats. We used twelve male Wistar rats randomly divided into experimental group and control group. The experimental group ran on a treadmill for rats with acclivity of 10 degrees, five times per week, daily during 70 minutes at a speed of 18 m / min for a period of 12 weeks. After the protocol, the animals were sacrificad and Achilles tendons were removed left and right, fixed and processed. We have twelve tendons in each group (n=12). After preparing slides using stains of Hematoxylin-Eosin and Picrosirius Red, histomorphometric analysis was performed of the same. The cell density increased in the experimental group compared to control, 626.08 ± 18.37 versus 445.08 ± 16.48, 615.67 in field 1 and ± 13.51 versus 460.00 ± 27.49, field 2, with p < 0.05 . There was a greater deposition of type III collagen in the experimental groups (50, 55 ± 4.002 versus 9.59 ± 0.435 with p < 0.001). It can be observed that the proposed model is effective to develop a degenerative tendinosis type Achilles tendon injury.