Preconditioning with lidocaine and xylazine in experimental equine jejunal ischaemia.

The research investigates the potential preconditioning effects of lidocaine and xylazine on equine jejunal ischaemia, a common gastrointestinal condition in horses. The study found that xylazine might have potential beneficial effects in easing ischaemia/reperfusion injury, while lidocaine showed no clear impact.

Study Methodology

• The study applied an in vivo experiment, conducted on ten horses under general anesthesia.
• These horses were divided into two groups: one was preconditioned with xylazine (group X), and the other with lidocaine (group L).
• A historical untreated control group (group C) was used for comparative analysis.
• The researchers applied a pre-established experimental model of equine jejunal ischaemia and collected intestinal samples pre-ischaemia, post-ischaemia, and following reperfusion.
• These samples were then subjected to a histomorphological examination based on a modified Chiu score and immunohistochemical staining for cleaved caspase-3, TUNEL, and calprotectin.

Study Results

• There was no significant progression of histomorphological mucosal injury from ischaemia to reperfusion among the groups, and neither were there remarkable differences in histomorphology.
• Post-ischaemia, the group preconditioned with xylazine (group X) had significantly fewer caspase-positive cells than the control group.
• Following reperfusion, group X also displayed substantially lower counts of calprotectin-positive cells compared to the control group.
• All groups exhibited an increase in caspase- and calprotectin-positive cells during reperfusion and a decrease in TUNEL-positive cells after reperfusion.

Study Limitations and Conclusions

• The researchers acknowledged the limitations of their study, citing the small sample size and the use of a historical control group as potential pitfalls.
• They suggested that the potential preconditioning effects of the drugs under investigation may be obscured by the impact of the protective anaesthetic agent, isoflurane, used during the experiment.
• Notably, preconditioning with lidocaine did not yield any observable effect on the studied variables, while xylazine demonstrated potential benefits with reduced cell counts of caspase- and calprotectin-positive cells.
• However, they point out that due to the lack of a concurrent reduction in histomorphological injury, the clinical significance of these results remains uncertain.