Inhibitory effect of triamcinolone acetonide on synthesis of inflammatory mediators in the equine.

This study investigates the effect of an anti-inflammatory drug, triamcinolone acetonide (TA), on inflammation mediators in horses. The findings suggest that TA suppresses the synthesis of bioactive eicosanoids, substances involved in inflammation, thus affirming its anti-inflammatory role.

Study Overview

• The study was aimed at understanding how TA affects the concentrations of bioactive eicosanoids in equine (horse) blood plasma.
• This is especially important as glucocorticoids, the class of drugs to which TA belongs, are commonly used in veterinary practice and can also mask pain in equine athletes, thus potentially increasing the risk of injury.

Methodology

• TA was administered intravenously to the horses at a dosage of 0.04 mg/kg.
• Equine whole blood samples were collected both before and after TA administration and subjected to different stimuli: methanol, calcium ionophore A-23187 (CI), or lipopolysaccharide (LPS) to stimulate ex-vivo synthesis of eicosanoids.
• The concentrations of eicosanoids in the plasma were then quantified using a technique called LC-MS/MRM.

Results

• Treatment with TA did not affect levels of a particular eicosanoid, thromboxane B2 (TXB2), when the blood was stimulated with CI.
• However, when treated with LPS, TXB2 along with three other eicosanoids (PGE2, PGF2α, and 15-(s)-HETE) decreased during 2-8 hours post-TA administration, but returned to normal levels after 24 hours.
• When the blood was treated with CI, another eicosanoid, LTB4, was suppressed after TA administration.
• But, when the blood collected post-TA administration was stimulated with LPS, the concentrations of LTB4 were not significantly different from the pre-TA administration samples.

Conclusion

• Through this study, it was concluded that a therapeutic dose of TA can suppress the biosynthesis of bioactive eicosanoids, thereby indicating its anti-inflammatory role in horses.
• These findings potentially have implications for the use of TA and similar glucocorticoids in veterinary practice, particularly in managing inflammation or pain in equine athletes.