The role of cyclooxygenase inhibitors in repair of ischaemic-injured jejunal mucosa in the horse.

This research investigates the impact of cyclooxygenase inhibitors, such as flunixin meglumine and etodolac, on the recovery of ischaemic intestinal injury in horses. The study suggests that the use of specific COX-2 inhibitors could be beneficial for horses suffering from colic.

Exploration of Cyclooxygenase Inhibitors

• The research focuses on cyclooxygenase inhibitors, which are administered to horses to mitigate the production of prostaglandins induced by endotoxin. Prostaglandins PGE2 and PGI2 activate the repair of an injured intestine.
• Cyclooxygenase consists of two isoforms: COX-1 and COX-2. COX-1 consistently produces prostaglandins while COX-2 prompts inflammation.

Hypothesis and Method

• The authors hypothesised that a nonspecific cyclooxygenase inhibitor called flunixin meglumine could slow down the repair of ischaemic intestinal injury since it prevents the production of reparative prostaglandins. On the other hand, they speculate that the selective COX-2 inhibitor, etodolac, could enable repair because it maintains COX-1 prostaglandin production.
• The study conducted experiments on sections of equine jejunum that were exposed to ischaemia for an hour and recovered in Ussing chambers for 4 hours.

Observations and Findings

• In tissues affected by ischaemia and treated with flunixin meglumine, the production of PGE2 and PGI2 was restricted, with no visible evidence of recovery based on measurements of transepithelial resistance.
• In contrast, untreated ischaemic tissues or those treated with etodolac, showed marked increases in PGE2 and PGI2 levels, alongside significant recovery of transepithelial resistance.

Conclusion

• The findings suggest that specific COX-2 inhibitors like etodolac could potentially be a better alternative to nonspecific cyclooxygenase inhibitors such as flunixin meglumine in treating horses with colic.