Characterization of equine vitamin D-binding protein, development of an assay, and assessment of plasma concentrations of the protein in healthy horses and horses with gastrointestinal disease.

The research article focuses on an investigation about equine vitamin D-binding protein (VDBP), its characterization, measurement procedure, and blood plasma levels in both healthy horses and horses suffering from gastrointestinal afflictions.

Purpose & Methods

• The aim of the investigation was to cleanse and distinguish equine VDBP from horse serum, and to evaluate the plasma concentrations of VDBP in both healthy horses and horses that have suffered a gastrointestinal injury or disease.
• The study involved examining healthy laboratory animals, namely eight mice and five rabbits; along with 61 healthy horses, 12 horses having intentionally caused intestinal ischemia and reperfusion (IR), and 59 horses with sudden onset gastrointestinal diseases.
• VDBP was purified from the serum of two healthy horses and a commercial service was used to obtain recombinant equine VDBP. Furthermore, mass spectrometry was utilized to identify equine VDBP. The researchers also raised monoclonal and polyclonal antibodies against equine VDBP, and established a rocket immunoelectrophoresis assay for equine VDBP.

Results & Conclusions

• Through the experiment, researchers established a reference range for plasma VDBP concentration in healthy horses, which was found to be between 531 to1382 mg/L.
• Following one hour of ischemia in horses with IR, plasma VDBP concentrations were notably reduced compared to pre-ischemia values. Moreover, horses with gastrointestinal diseases presenting colic symptoms for less than 12 hours had significantly lower concentrations of plasma VDBP than healthy horses.
• Bringing these observations together, the study concluded that horses with acute gastrointestinal injury or disease showed significantly reduced plasma VDBP concentrations.
• Nevertheless, the researchers made it clear that more research is needed, including the creation of a clinically relevant assay, to determine the reliability of VDBP as a diagnostic and prognostic marker in horses.