Presence of Myeloperoxidase in Lamellar Tissue of Horses Induced by an Euglycemic Hyperinsulinemic Clamp.
Authors: Storms Nazare, Medina Torres Carlos, Franck Thierry, Sole Guitart Albert, de la Rebière Geoffroy, Serteyn Didier
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Metabolic laminitis remains poorly understood compared to systemic inflammatory forms, particularly regarding the cellular mechanisms driving tissue breakdown at the dermal-epidermal junction. This descriptive study used prolonged euglycemic hyperinsulinaemic clamping (pEHC)—a gold-standard protocol for inducing insulin dysregulation—to investigate whether neutrophil activation markers appear in lamellar tissue during early endocrinopathic laminitis, examining three treated horses and two healthy controls. Within 48 hours of pEHC treatment, immunohistochemical analysis revealed significantly elevated myeloperoxidase (MPO) concentrations in the dermal lamellae of treated horses alongside characteristic histopathological changes of insulin-induced laminitis, whereas control tissue showed minimal MPO staining. These findings suggest that neutrophil degranulation and the subsequent release of destructive enzymatic compounds—previously established as central to systemic inflammatory laminitis—also play a direct role in metabolic laminitis pathogenesis. For practitioners managing equine metabolic disease, this work strengthens the rationale for aggressive glycaemic control and tight insulin management in susceptible individuals, and potentially supports investigation of anti-inflammatory therapies targeting neutrophil activation as adjunctive treatments during acute metabolic laminitis episodes.
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Practical Takeaways
- •Neutrophil-mediated inflammation contributes to metabolic laminitis, suggesting anti-inflammatory strategies targeting neutrophil activity may be therapeutically relevant
- •Early lamellar changes in hyperinsulinemic horses involve inflammatory cascades detectable at histological level before clinical lameness becomes obvious
- •Understanding the neutrophil activation pathway in endocrinopathic laminitis may lead to novel diagnostic or preventive interventions beyond traditional metabolic management
Key Findings
- •Myeloperoxidase presence was significantly increased in dermal lamellae of horses subjected to prolonged euglycemic hyperinsulinemic clamp compared to healthy controls
- •Histopathological changes characteristic of insulin-induced laminitis were observed in lamellar tissue after 48 hours of pEHC treatment
- •Neutrophil activation appears to play a role in endocrinopathic laminitis pathophysiology, similar to SIRS-associated laminitis