Assessment of peripheral blood neutrophil respiratory burst, phagocytosis and apoptosis in obese non-insulin dysregulated horses.

The study investigates the effect of obesity on the function of neutrophils, a type of white blood cell, in horses that don’t have insulin dysregulation. It found that these horses’ neutrophils produced more reactive oxygen species (ROS), a process called oxidative burst, but their ability to engulf particles (phagocytosis) and undergo programmed cell death (apoptosis) was unchanged.

Objective and Methodology

• The study aimed to evaluate how obesity affects different neutrophil functions: oxidative burst, phagocytosis and apoptosis in horses that aren’t insulin dysregulated.
• A total of 12 horses were evaluated: 7 lean horses with a body condition score (BCS) of 4-6/9, and 5 obese horses with a BCS of 8-9.
• To ensure the horses selected for the study were not insulin dysregulated, all the animals had to undergo two metabolic tests: an oral glucose test (OGT) and an insulin response test (IRT).
• Neutrophils from the horses were isolated through a discontinuous density gradient approach using a single blood sample from each animal.
• The study then performed assays to measure the neutrophils’ phagocytosis, apoptosis, and ROS production capabilities.

Key Findings

• The results show that neutrophils from obese, non-insulin dysregulated horses produced significantly more ROS (P < 0.0001).
• No significant changes were observed in the capability of the neutrophils to undergo phagocytosis or apoptosis when compared with the lean group (P > 0.05).

Conclusion and Relevance

• The study concludes that obesity itself − regardless of other potential endocrine disorders − modifies the capability of the neutrophils to produce ROS.
• This research provides valuable insights into how obesity affects the equine immune system and contributes to our understanding of obesity’s role in the development of endocrine disorders in horses.
• More research is needed to deepen our understanding of the implications of this discovery for equine health.