Immunolocalization of decorin, a small leucin-rich proteoglycan, in the normal and injured horse tendon

Abstract

The aim of this study was to evaluate the intensity of decorin in normal and the injured equine cadaver limbs. The study was carried out using superficial digital flexor tendon (SDFT) samples harvested from equine cadaver limbs. Randomly assigned left or right equine distal forelimbs were collected in normal (7 - 14 years old ± 2.86 SD) and injured (6 - 16 years old ± 3.64 SD) SDFT. Small pieces of approximately 5 x 5 x 3 mm were collected from normal and the injured areas at the mid-most metacarpal regions and fixed in 4% paraformaldehyde at room temperature. They were routinely prepared for H&E staining in order to confirm whether they were normal or injured. Then they were prepared for immunological assay, the primary and the secondary antibodies were prepared in a standard ratio. The results showed that the distribution of decorin was varied between fascicles and the interfascicular matrix (IFM), and the latter showed greater intensity than the fascicles. The injured tendons showed up-regulation of decorin, it was intensively expressed in all the cases of injured tendon, particularly fascicles showed significant up-regulation when compared to the normal tendon. It was concluded that decorin was varied regionally, and the injured tendons presented a significant up-regulation.

Keywords

• sdft
• proteoglycan
• decorin
• tendinopathy