Evaluation of the possible role of prostaglandin F(2 alpha) in laminitis induced in horses by nasogastric administration of black walnut heartwood extract.

This research studied the role of a compound called prostaglandin F(2 alpha) in the early stages of a painful and debilitating hoof disease called laminitis in horses which was induced by a substance found in black walnut heartwood extract.

Objective and Methods

• The study aimed to shed light on the role of a specific molecule, prostaglandin F(2 alpha) (PGF(2 alpha)), during the early stages of laminitis in horses. Laminitis was induced by giving the horses black walnut heartwood extract (BWHE).
• To achieve this, the researchers divided 10 adult mixed-breed horses into two groups. For one group, laminitis was induced using BWHE, while the other group was given a placebo (water).
• Blood samples were drawn to assess the plasma concentrations of PGF(2 alpha) at regular intervals after administration of either BWHE or the placebo.
• The responses of the horses’ blood vessels, specifically the laminar arteries and veins, to varying concentrations of PGF(2 alpha) were measured. Responses were gauged both before and after the blood vessels had been preincubated with several prostanoid and thromboxane receptor antagonists.

Results and Findings

• After being given BWHE, the horses exhibited increased concentrations of PGF(2 alpha) in their blood and decreased white blood cell counts.
• Under normal (control) conditions, PGF(2 alpha) induced contraction in the laminar veins of the horses, but not their laminar arteries. The same selectivity was observed after the horses had been given BWHE, but with a lower degree of venous contraction.
• When prostanoid antagonist SQ 29,548 was used to preincubate the laminar veins, control horses experienced a minor degree of dilation in response to PGF(2 alpha), while those given BWHE did not.

Conclusion and Implications

• The study concluded that PGF(2 alpha) may be involved in the inflammatory and vascular dysfunction that occur in the early stages of laminitis.
• The researchers suggest that PGF(2 alpha) and other similar molecules (prostanoids) could be potential targets for preventing acute laminitis in horses.