Characterization of collagen fibrils after equine suspensory ligament injury: an ultrastructural and biochemical approach.

The research article focuses on studying changes in collagen fibrils in horses’ suspensory ligaments after injury using biochemical and ultrastructural methods. It has been found that injuries lead to alterations in the fibril’s organization and composition, potentially impacting the tissue’s quality and mechanical properties.

Research Objectives and Methodologies

The study aimed to understand the changes in horses’ suspensory ligament (SL) collagen fibrils after injury. The reasons for this investigation are:

• SL injuries are a major cause of lameness in horses.
• The quality and mechanical properties of ligament tissues are largely dependent on collagen fibril’s morphology and types.

To carry out this research, the team selected eight Warmblood horses that showed visible signs of injury in one forelimb SL. The steps to investigate included:

• Examining specimens of these injured SLs under a transmission electron microscope (TEM) for abnormalities in fibril organization, diameter, and shape.
• Using a biochemical method to purify collagen types I, III, and V from these samples.
• Analyzing the levels of these collagen types in damaged tissues via densitometric analysis after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

Findings of The Study

TEM revealed changes in the fibrils’ organization, diameter, and shape in the injured ligaments, indicating abnormal collagen behavior due to injury.

The densitometric analysis after SDS-PAGE revealed noteworthy changes in collagen content:

• The percentage of type III and type V collagen was significantly higher in the damaged tissues compared to normal ones, with an average increase of 20.9% and 17.3%, respectively.
• Conversely, the level of type I collagen was significantly lower in the damaged tissues with a mean decrease of 15.2%.

Conclusion and Implication

These changes in collagen fibril organization and types are seen as indicators of a decrease in the quality and mechanical properties of affected ligament tissues. The findings hold significance for future research focusing on tissue regeneration, potentially leading to the development of more effective treatment strategies for SL injuries in horses.