The effects of phenylbutazone on the morphology and prostaglandin concentrations of the pyloric mucosa of the equine stomach.

The research examines the impact of the nonsteroidal anti-inflammatory drug phenylbutazone on the stomach lining of horses, exploring its role in inducing gastric ulcers.

Research Process

• The researchers administered phenylbutazone daily to 12 horses through an IV at a dose of 13.46 mg/kg body weight. The horses were euthanized at different times following the initial injection (24, 48, 72, and 96 hours). Eight untreated horses were used as controls for comparison.
• Post-treatment, the study identified the presence of pyloric erosions, which worsened over time, starting from 24 hours after the initial injection. These erosions featured characteristics such as sloughing of the surface epithelium, formation of subepithelial blebs, necrosis of the lamina propria, degeneration of capillary walls, and microthrombosis of the pyloric mucosa capillaries.
• These erosion sites displayed abundant neutrophils, fibrin, and cellular debris. The damaged pyloric mucosa was then scrutinized for morphological defects, including cellular swelling of endothelium, pericytes, and smooth muscle cells, and significant alterations in the state of capillaries and venules.
• Blood leakage and edema were noted. None of these conditions were witnessed in the control horses.

Results and Conclusion

• The study revealed that phenylbutazone causes a microvascular injury that correlates with the formation of pyloric erosions. It confirmed the negative impacts of using this medication on the stomach health of horses.
• In addition to exploring the morphological damage, the study measured concentrations of prostacyclin and prostaglandin E2 in the pyloric mucosa at 48 and 96 hours post injection. No significant deviation from the controls was noted.
• These findings indicate that there’s little correlation between prostaglandin concentrations in the mucosa and the manifestation of pyloric erosions after 48 hours. Thus, while phenylbutazone does result in significant gastric health concerns, it doesn’t appear to significantly affect these specific prostaglandin levels.