Effect of firocoxib or flunixin meglumine on recovery of ischemic-injured equine jejunum.

This research paper explores how administering the drugs firocoxib and flunixin meglumine affects the recovery of a horse’s small intestine (jejunum) after it experiences oxygen deprivation (ischemic injury). Compared to flunixin meglumine, firocoxib was found to not hinder tissue healing and was efficacious as an analgesic, suggesting its usefulness in treating equine ischemic intestinal injuries.

Methodology and Procedures

• The experiment involved 18 horses divided evenly into three groups. Each group received either saline solution, flunixin meglumine, or firocoxib before being subject to two hours of jejunal ischemia, a condition where the jejunum tissue is deprived of oxygen.
• The horses’ pain levels were tracked using pain scores, while the opioid drug butorphanol was administered for pain relief.
• Upon 18 hours, intestinal tissues, both injured and healthy, were evaluated in Ussing chambers to measure electrical resistance across the tissues and their permeability to lipopolysaccharide, a molecule which could imply bacterial infection.
• Surface area of the damaged villus (small, finger-like projections inside the intestine) was assessed using histomorphometry, a procedure that quantitatively analyzes microscopic structure.
• The researchers conducted Western Blot analyses, a method to detect specific proteins, for Cyclooxygenase-1 (COX-1) and Cyclooxygenase-2 (COX-2).
• Levels of thromboxane B(2) and prostaglandin E(2) metabolite (PGEM) – substances related to inflammation and blood flow regulation – were determined in the blood.

Key Findings

• Post-surgery pain scores did not noticeably differ in horses treated with flunixin meglumine or firocoxib.
• Remarkably, the electrical resistance of the oxygen-deprived jejunum was significantly lower in horses treated with flunixin meglumine compared to others. This could suggest poorer tissue integrity in these animals.
• Likewise, lipopolysaccharide permeability was significantly increased in the flunixin meglumine group, implying increased vulnerability to bacterial infections.
• Treatment did not affect epithelial restitution, or repair of the intestinal lining.
• COX-1 protein was always detected and COX-2 protein expression increased after the jejunum suffered ischemia.
• Notably, thromboxane B(2) levels dropped with flunixin meglumine treatment but rose in horses receiving firocoxib or saline. Both flunixin meglumine and firocoxib prevented an increase in PGEM levels after surgery.

Conclusions

• Overall, these observations show that treatment with flunixin meglumine hampered the mucosal recovery of oxygen-deprived jejunum, whereas firocoxib did not. This suggests that firocoxib might be the preferable drug in horses recovering from ischemic intestinal injuries.