Effect of lipopolysaccharide infusion on gene expression of inflammatory cytokines in normal horses in vivo.
Authors: Nieto J E, MacDonald M H, Braim A E Poulin, Aleman M
Journal: Equine veterinary journal
Summary
# Editorial Summary Bacterial endotoxin (lipopolysaccharide or LPS) triggers rapid and profound inflammatory responses in horses, a critical consideration given the prevalence of endotoxaemia in colic cases and other systemic conditions. Nieto and colleagues administered intravenous LPS to six healthy horses whilst monitoring gene expression of five key inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-8, and TNF-α) via real-time PCR, comparing responses to saline controls over a three-hour period. All cytokine genes upregulated sharply following LPS challenge, though with distinct kinetic profiles: IL-1α, IL-1β, IL-8, and TNF-α peaked at 60 minutes post-infusion, whilst IL-6 expression peaked later at 90 minutes, with IL-1β and IL-6 remaining elevated above baseline at three hours whilst the others had resolved. Understanding these differential inflammatory response patterns is valuable for practitioners managing endotoxaemic cases, as it demonstrates that cytokine production is both rapid and prolonged, supporting the rationale for early intervention in conditions such as colic, endotoxic shock, and severe infections where sustained cytokine elevation drives systemic complications and clinical deterioration.
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Practical Takeaways
- •Understanding the temporal kinetics of inflammatory cytokine expression helps interpret clinical responses to endotoxaemia in colic cases
- •Different cytokines have different peak expression times and recovery periods, which may inform the window for therapeutic intervention in endotoxic horses
- •IL-1β and IL-6 sustained elevation may be particularly important monitoring targets in managing horses with endotoxaemic episodes
Key Findings
- •All inflammatory cytokine genes (IL-1α, IL-1β, IL-6, IL-8, TNF-α) were upregulated following LPS infusion in healthy horses
- •IL-1α, IL-1β, IL-8 and TNF-α peaked at 60 minutes post-LPS administration, while IL-6 peaked at 90 minutes
- •IL-1β and IL-6 messenger RNA remained elevated above baseline 3 hours post-infusion, whereas IL-1α, IL-8 and TNF-α returned to baseline by 3 hours