Effects of phenylbutazone, indomethacin, prostaglandin E2, butyrate, and glutamine on restitution of oxidant-injured right dorsal colon of horses in vitro.

This research investigates the impact of certain drugs and compounds on the recovery of damaged colon tissue in horses. It finds that glutamine aids in the restoration process, whereas phenylbutazone, indomethacin and others do not provide any significant recovery benefits.

Methodology

• The study used the right dorsal colon from 9 adult horses that were euthanized for reasons unrelated to gastrointestinal tract disease.
• Mucosal segments from the colon were exposed to Hypochlorous acid (HOCl), inducing damage mimicking that of oxidants.
• These damaged segments were then incubated in solutions containing various compounds namely phenylbutazone, indomethacin, prostaglandin E2 (PGE2), glutamine, and butyrate.
• Using a device known as Ussing chambers, researchers measured the resistance across the epithelial layer of the mucosa and its permeability to mannitol, a type of sugar alcohol used to test permeability.
• All treated sections of the mucosa were histologically examined to assess changes at a microscopic level.

Results

• The researchers found that the HOCl-exposed mucosa had a lower resistance and higher permeability to mannitol, as compared to healthy tissue. This implies that the damaged tissues had a compromised barrier function, allowing more substances to pass through.
• Phenylbutazone and indomethacin neither significantly improved resistance nor reduced permeability. Similarly, Butyrate and PGE2 also had no evident effects.
• In contrast, the resistance of the damaged mucosa partially recovered during the incubation period when treated with glutamine. It also decreased the permeability of the mucosa to mannitol.
• The histologic changes observed correlated with changes in resistance and permeability, reflecting the improvements seen with glutamine treatment.

Conclusion

• Based on the results, the study concluded that phenylbutazone and indomethacin do not significantly contribute to the healing process of oxidant-damaged mucosa of the equine colon when tested in vitro.
• Glutamine, however, was found to improve recovery, indicating it could be beneficial to facilitate mucosal restitution following injury.
• Hence, this study highlights a potential therapeutic role for glutamine in treating colon injuries in horses.