Characterization of a sterile soft-tissue inflammation model in thoroughbred horses.

The research paper discusses a new method for eliciting sterile soft-tissue inflammation in Thoroughbred horses via subcutaneous tissue chambers injecting with sterile lambda carrageenan solution, and the subsequent effects of this inflammation on various measures of tissue fluid and temperature.

Model and Procedure

• The researchers conducted this study by using tissue chambers, placed under the skin of the horse. The purpose of these chambers was to create a controlled, isolate area where inflammation could be induced and monitored.
• Inflammation was initiated by injecting a sterile solution of lambda carrageenan into these tissue chambers. Lambda carrageenan is a substance extracted from red seaweed which is known to create inflammation responses in the body.

Measurements and Results

• Over the course of the experiment, the researchers observed and recorded multiple changes in the inflamed tissue chambers and control (non-inflamed) chambers. They monitored temporal changes in certain aspect of the tissue fluid including oxygen and carbon dioxide tensions, pH, bicarbonate, protein, albumin, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) concentrations, and cell counts, in particular leucocytes which are key for immune response.
• Furthermore, skin temperatures over the inflamed and control chambers were compared to see if the inflammation caused any noticeable difference.
• The results showed that the carrageenan-induced inflammation resulted in significant increases in tissue-fluid carbon dioxide tension, leucocyte count, albumin, and PGE2 and LTB4 concentrations, which are biomarkers associated with inflammation in the body.
• Interestingly, they also found that the inflammation caused a significant decrease in tissue fluid’s pH and bicarbonate concentration, suggesting an accumulation of acids due to inflammation.
• However, no significant changes were noted in tissue-fluid protein concentration, differential cell counts, or skin temperature over the chambers after inflammation was induced.

Conclusions and Implications

• The authors concluded that this subcutaneous tissue chamber model could be an effective method for studying the pathophysiology of self-contained, non-immune inflammatory processes.
• The researchers suggest the model could also be very useful in studying the distribution and effects of anti-inflammatory drugs on various aspects of the inflammatory process, which opens up avenues for new research into the treatment of inflammation in racehorses and other equine species.